= Collections API
:page-toclevels: 1
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The Collections API is used to create, remove, or reload collections.

In the context of SolrCloud you can use it to create collections with a specific number of shards and replicas, move replicas or shards, and create or delete collection aliases.

[[create]]
== CREATE: Create a Collection

`/admin/collections?action=CREATE&name=_name_`

=== CREATE Parameters

The CREATE action allows the following parameters:

`name`::
The name of the collection to be created. This parameter is required.

`router.name`::
The router name that will be used. The router defines how documents will be distributed among the shards. Possible values are `implicit` or `compositeId`, which is the default.
+
The `implicit` router does not automatically route documents to different shards. Whichever shard you indicate on the indexing request (or within each document) will be used as the destination for those documents.
+
The `compositeId` router hashes the value in the uniqueKey field and looks up that hash in the collection's clusterstate to determine which shard will receive the document, with the additional ability to manually direct the routing.
+
When using the `implicit` router, the `shards` parameter is required. When using the `compositeId` router, the `numShards` parameter is required.
+
For more information, see also the section <<shards-and-indexing-data-in-solrcloud.adoc#document-routing,Document Routing>>.

`numShards`::
The number of shards to be created as part of the collection. This is a required parameter when the `router.name` is `compositeId`.

`shards`::
A comma separated list of shard names, e.g., `shard-x,shard-y,shard-z`. This is a required parameter when the `router.name` is `implicit`.

`replicationFactor`::
The number of replicas to be created for each shard. The default is `1`.
+
This will create a NRT type of replica. If you want another type of replica, see the `tlogReplicas` and `pullReplica` parameters below. See the section <<shards-and-indexing-data-in-solrcloud.adoc#types-of-replicas,Types of Replicas>> for more information about replica types.

`nrtReplicas`::
The number of NRT (Near-Real-Time) replicas to create for this collection. This type of replica maintains a transaction log and updates its index locally. If you want all of your replicas to be of this type, you can simply use `replicationFactor` instead.

`tlogReplicas`::
The number of TLOG replicas to create for this collection. This type of replica maintains a transaction log but only updates its index via replication from a leader. See the section <<shards-and-indexing-data-in-solrcloud.adoc#types-of-replicas,Types of Replicas>> for more information about replica types.

`pullReplicas`::
The number of PULL replicas to create for this collection. This type of replica does not maintain a transaction log and only updates its index via replication from a leader. This type is not eligible to become a leader and should not be the only type of replicas in the collection. See the section <<shards-and-indexing-data-in-solrcloud.adoc#types-of-replicas,Types of Replicas>> for more information about replica types.

`maxShardsPerNode`::
When creating collections, the shards and/or replicas are spread across all available (i.e., live) nodes, and two replicas of the same shard will never be on the same node.
+
If a node is not live when the CREATE action is called, it will not get any parts of the new collection, which could lead to too many replicas being created on a single live node. Defining `maxShardsPerNode` sets a limit on the number of replicas the CREATE action will spread to each node.
+
If the entire collection can not be fit into the live nodes, no collection will be created at all. The default `maxShardsPerNode` value is `1`. A value of `-1` means unlimited. If a `policy` is also specified then the stricter of `maxShardsPerNode` and policy rules apply.

`createNodeSet`::
Allows defining the nodes to spread the new collection across. The format is a comma-separated list of node_names, such as `localhost:8983_solr,localhost:8984_solr,localhost:8985_solr`.
+
If not provided, the CREATE operation will create shard-replicas spread across all live Solr nodes.
+
Alternatively, use the special value of `EMPTY` to initially create no shard-replica within the new collection and then later use the <<addreplica,ADDREPLICA>> operation to add shard-replicas when and where required.

`createNodeSet.shuffle`::
Controls whether or not the shard-replicas created for this collection will be assigned to the nodes specified by the `createNodeSet` in a sequential manner, or if the list of nodes should be shuffled prior to creating individual replicas.
+
A `false` value makes the results of a collection creation predictable and gives more exact control over the location of the individual shard-replicas, but `true` can be a better choice for ensuring replicas are distributed evenly across nodes. The default is `true`.
+
This parameter is ignored if `createNodeSet` is not also specified.

`collection.configName`::
Defines the name of the configuration (which *must already be stored in ZooKeeper*) to use for this collection. If not provided, Solr will use the configuration of `_default` configSet to create a new (and mutable) configSet named `<collectionName>.AUTOCREATED` and will use it for the new collection. When such a collection (that uses a copy of the _default configset) is deleted, the autocreated configset is not deleted by default.

`router.field`::
If this parameter is specified, the router will look at the value of the field in an input document to compute the hash and identify a shard instead of looking at the `uniqueKey` field. If the field specified is null in the document, the document will be rejected.
+
Please note that <<realtime-get.adoc#realtime-get,RealTime Get>> or retrieval by document ID would also require the parameter `\_route_` (or `shard.keys`) to avoid a distributed search.

`property._name_=_value_`::
Set core property _name_ to _value_. See the section <<defining-core-properties.adoc#defining-core-properties,Defining core.properties>> for details on supported properties and values.

`autoAddReplicas`::
When set to `true`, enables automatic addition of replicas when the number of active replicas falls below the value set for `replicationFactor`. This may occur if a replica goes down, for example. The default is `false`, which means new replicas will not be added.
+
While this parameter is provided as part of Solr's set of features to provide autoscaling of clusters, it is available even when you have not implemented any other part of autoscaling (such as a policy). See the section <<solrcloud-autoscaling-auto-add-replicas.adoc#the-autoaddreplicas-parameter,SolrCloud Autoscaling Automatically Adding Replicas>> for more details about this option and how it can be used.

`async`::
Request ID to track this action which will be <<Asynchronous Calls,processed asynchronously>>.

`rule`::
Replica placement rules. See the section <<rule-based-replica-placement.adoc#rule-based-replica-placement,Rule-based Replica Placement>> for details.

`snitch`::
Details of the snitch provider. See the section <<rule-based-replica-placement.adoc#rule-based-replica-placement,Rule-based Replica Placement>> for details.

`policy`:: Name of the collection-level policy. See <<solrcloud-autoscaling-policy-preferences.adoc#collection-specific-policy, Defining Collection-Specific Policies >> for details.

`waitForFinalState`::
If `true`, the request will complete only when all affected replicas become active. The default is `false`, which means that the API will return the status of the single action, which may be before the new replica is online and active.

`withCollection`::
The name of the collection with which all replicas of this collection must be co-located. The collection must already exist and must have a single shard named `shard1`.
See <<colocating-collections.adoc#colocating-collections, Colocating collections>> for more details.

`alias`::
Starting with version 8.1 when a collection is created additionally an alias can be created
that points to this collection. This parameter allows specifying the name of this alias, effectively combining
this operation with <<createalias, CREATEALIAS>>

Collections are first created in read-write mode but can be put in `readOnly`
mode using the <<modifycollection, MODIFYCOLLECTION>> action.

=== CREATE Response

The response will include the status of the request and the new core names. If the status is anything other than "success", an error message will explain why the request failed.

=== Examples using CREATE

*Input*

[source,text]
----
http://localhost:8983/solr/admin/collections?action=CREATE&name=newCollection&numShards=2&replicationFactor=1&wt=xml
----

*Output*

[source,xml]
----
<response>
  <lst name="responseHeader">
    <int name="status">0</int>
    <int name="QTime">3764</int>
  </lst>
  <lst name="success">
    <lst>
      <lst name="responseHeader">
        <int name="status">0</int>
        <int name="QTime">3450</int>
      </lst>
      <str name="core">newCollection_shard1_replica1</str>
    </lst>
    <lst>
      <lst name="responseHeader">
        <int name="status">0</int>
        <int name="QTime">3597</int>
      </lst>
      <str name="core">newCollection_shard2_replica1</str>
    </lst>
  </lst>
</response>
----

[[modifycollection]]
== MODIFYCOLLECTION: Modify Attributes of a Collection

`/admin/collections?action=MODIFYCOLLECTION&collection=_<collection-name>_&__<attribute-name>__=__<attribute-value>__&__<another-attribute-name>__=__<another-value>__&__<yet_another_attribute_name>__=`

It's possible to edit multiple attributes at a time. Changing these values only updates the z-node on ZooKeeper, they do not change the topology of the collection. For instance, increasing `replicationFactor` will _not_ automatically add more replicas to the collection but _will_ allow more ADDREPLICA commands to succeed.

An attribute can be deleted by passing an empty value. For example, `yet_another_attribute_name=` (with no value) will delete the `yet_another_attribute_name` parameter from the collection.

=== MODIFYCOLLECTION Parameters

`collection`::
The name of the collection to be modified. This parameter is required.

`_attribute_=_value_`::
Key-value pairs of attribute names and attribute values.

At least one `_attribute_` parameter is required.

The attributes that can be modified are:

* maxShardsPerNode
* replicationFactor
* autoAddReplicas
* collection.configName
* rule
* snitch
* policy
* withCollection
* readOnly
* other custom properties that use a `property.` prefix

See the <<create,CREATE action>> section above for details on these attributes.

[[readonlymode]]
==== Read-only mode
Setting the `readOnly` attribute to `true` puts the collection in read-only mode,
in which any index update requests are rejected. Other collection-level actions (eg. adding /
removing / moving replicas) are still available in this mode.

The transition from the (default) read-write to read-only mode consists of the following steps:

* the `readOnly` flag is changed in collection state,
* any new update requests are rejected with 403 FORBIDDEN error code (ongoing
  long-running requests are aborted, too),
* a forced commit is performed to flush and commit any in-flight updates.

NOTE: This may potentially take a long time if there are still major segment merges running
 in the background.

* a collection <<reload, RELOAD action>> is executed.

Removing the `readOnly` property or setting it to false enables the
processing of updates and reloads the collection.

[[reindexcollection]]
== REINDEXCOLLECTION: Re-index a Collection

`/admin/collections?action=REINDEXCOLLECTION&name=_name_`

The REINDEXCOLLECTION command re-indexes a collection using existing data from the
source collection.

NOTE: Re-indexing is potentially a lossy operation - some of the existing indexed data that is not
available as stored fields may be lost, so users should use this command
with caution, evaluating the potential impact by using different source and target
collection names first, and preserving the source collection until the evaluation is
complete.

The target collection must not exist (and may not be an alias). If the target
collection name is the same as the source collection then first a unique sequential name
will be generated for the target collection, and then after re-indexing is done an alias
will be created that points from the source name to the actual sequentially-named target collection.

When re-indexing is started the source collection is put in <<readonlymode,read-only mode>> to ensure that
all source documents are properly processed.

Using optional parameters a different index schema, collection shape (number of shards and replicas)
or routing parameters can be requested for the target collection.

Re-indexing is executed as a streaming expression daemon, which runs on one of the
source collection's replicas. It is usually a time-consuming operation so it's recommended to execute
it as an asynchronous request in order to avoid request time outs. Only one re-indexing operation may
execute concurrently for a given source collection. Long-running, erroneous or crashed re-indexing
operations may be terminated by using the `abort` option, which also removes partial results.

=== REINDEXCOLLECTION Parameters

`name`::
Source collection name, may be an alias. This parameter is required.

`cmd`::
Optional command. Default command is `start`. Currently supported commands are:
* `start` - default, starts processing if not already running,
* `abort` - aborts an already running re-indexing (or clears a left-over status after a crash),
and deletes partial results,
* `status` - returns detailed status of a running re-indexing command.

`target`::
Target collection name, optional. If not specified a unique name will be generated and
after all documents have been copied an alias will be created that points from the source
collection name to the unique sequentially-named collection, effectively "hiding"
the original source collection from regular update and search operations.

`q`::
Optional query to select documents for re-indexing. Default value is `\*:*`.

`fl`::
Optional list of fields to re-index. Default value is `*`.

`rows`::
Documents are transferred in batches. Depending on the average size of the document large
batch sizes may cause memory issues. Default value is 100.

`configName`::
`collection.configName`::
Optional name of the configset for the target collection. Default is the same as the
source collection.

There's a number of optional parameters that determine the target collection layout. If they
are not specified in the request then their values are copied from the source collection.
The following parameters are currently supported (described in details in the <<create,CREATE collection>> section):
`numShards`, `replicationFactor`, `nrtReplicas`, `tlogReplicas`, `pullReplicas`, `maxShardsPerNode`,
`autoAddReplicas`, `shards`, `policy`, `createNodeSet`, `createNodeSet.shuffle`, `router.*`.

`removeSource`::
Optional boolean. If true then after the processing is successfully finished the source collection will
be deleted.

`async`::
Optional request ID to track this action which will be <<Asynchronous Calls,processed asynchronously>>.

When the re-indexing process has completed the target collection is marked using
`property.rx: "finished"`, and the source collection state is updated to become read-write.
On any errors the command will delete any temporary and target collections and also reset the
state of the source collection's read-only flag.

=== Examples using REINDEXCOLLECTION

*Input*

[source,text]
----
http://localhost:8983/solr/admin/collections?action=REINDEXCOLLECTION&name=newCollection&numShards=3&configName=conf2&q=id:aa*&fl=id,string_s
----
This request specifies a different schema for the target collection, copies only some of the fields, selects only the documents
matching a query, and also potentially re-shapes the collection by explicitly specifying 3 shards. Since the target collection
hasn't been specified in the parameters a collection with a unique name eg. `.rx_newCollection_2` will be created and on success
an alias pointing from `newCollection` to `.rx_newCollection_2` will be created, effectively replacing the source collection
for the purpose of indexing and searching. The source collection is assumed to be small so a synchronous request was made.

*Output*

[source,json]
----
{
  "responseHeader":{
    "status":0,
    "QTime":10757},
  "reindexStatus":{
    "phase":"done",
    "inputDocs":13416,
    "processedDocs":376,
    "actualSourceCollection":".rx_newCollection_1",
    "state":"finished",
    "actualTargetCollection":".rx_newCollection_2",
    "checkpointCollection":".rx_ck_newCollection"
  }
}
----
As a result a new collection `.rx_newCollection_2` has been created, with selected documents re-indexed to 3 shards, and
with an alias pointing from `newCollection` to this one. The status also shows that the source collection
was already an alias to `.rx_newCollection_1`, which was likely a result of a previous re-indexing.

[[reload]]
== RELOAD: Reload a Collection

`/admin/collections?action=RELOAD&name=_name_`

The RELOAD action is used when you have changed a configuration in ZooKeeper.

=== RELOAD Parameters

`name`::
The name of the collection to reload. This parameter is required.

`async`::
Request ID to track this action which will be <<Asynchronous Calls,processed asynchronously>>.

=== RELOAD Response

The response will include the status of the request and the cores that were reloaded. If the status is anything other than "success", an error message will explain why the request failed.

=== Examples using RELOAD

*Input*

[source,text]
----
http://localhost:8983/solr/admin/collections?action=RELOAD&name=newCollection&wt=xml
----

*Output*

[source,xml]
----
<response>
  <lst name="responseHeader">
    <int name="status">0</int>
    <int name="QTime">1551</int>
  </lst>
  <lst name="success">
    <lst name="10.0.1.6:8983_solr">
      <lst name="responseHeader">
        <int name="status">0</int>
        <int name="QTime">761</int>
      </lst>
    </lst>
    <lst name="10.0.1.4:8983_solr">
      <lst name="responseHeader">
        <int name="status">0</int>
        <int name="QTime">1527</int>
      </lst>
    </lst>
  </lst>
</response>
----

[[rename]]
== RENAME: Rename a Collection

`/admin/collections?action=RENAME&name=_existingName_&target=_targetName_`

Renaming a collection sets up a standard alias that points to the underlying collection, so
that the same (unmodified) collection can now be referred to in query, index and admin operations
using the new name.

This command does NOT actually rename the underlying Solr collection - it sets up a new one-to-one alias
using the new name, or renames the existing alias so that it uses the new name, while still referring to
the same underlying Solr collection. However, from the user's point of view the collection can now be
accessed using the new name, and the new name can be also referred to in other aliases.

The following limitations apply:

* the existing name must be either a SolrCloud collection or a standard alias referring to a single collection.
Aliases that refer to more than 1 collection are not supported.
* the existing name must not be a Routed Alias.
* the target name must not be an existing alias.

=== RENAME Command Parameters

`name`::
Name of the existing SolrCloud collection or an alias that refers to exactly one collection and is not
a Routed Alias.

`target`::
Target name of the collection. This will be the new alias that refers to the underlying SolrCloud collection.
The original name (or alias) of the collection will be replaced also in the existing aliases so that they
also refer to the new name. Target name must not be an existing alias.

=== Examples using RENAME
Assuming there are two actual SolrCloud collections named `collection1` and `collection2`,
and the following aliases already exist:

* `col1 -&gt; collection1`: this resolves to `collection1`.
* `col2 -&gt; collection2`: this resolves to `collection2`.
* `simpleAlias -&gt; col1`: this resolves to `collection1`.
* `compoundAlias -&gt; col1,col2`: this resolves to `collection1,collection2`

The RENAME of `col1` to `foo` will change the aliases to the following:

* `foo -&gt; collection1`: this resolves to `collection1`.
* `col2 -&gt; collection2`: this resolves to `collection2`.
* `simpleAlias -&gt; foo`: this resolves to `collection1`.
* `compoundAlias -&gt; foo,col2`: this resolves to `collection1,collection2`.

If we then rename `collection1` (which is an actual collection name) to `collection2` (which is also
an actual collection name) the following aliases will exist now:

* `foo -&gt; collection2`: this resolves to `collection2`.
* `col2 -&gt; collection2`: this resolves to `collection2`.
* `simpleAlias -&gt; foo`: this resolves to `collection2`.
* `compoundAlias -&gt; foo,col2`: this would resolve now to `collection2,collection2` so it's reduced to simply `collection2`.
* `collection1` -&gt; `collection2`: this newly created alias effectively hides `collection1` from regular query and
update commands, which are directed now to `collection2`.


[[splitshard]]
== SPLITSHARD: Split a Shard

`/admin/collections?action=SPLITSHARD&collection=_name_&shard=_shardID_`

Splitting a shard will take an existing shard and break it into two pieces which are written to disk as two (new) shards. The original shard will continue to contain the same data as-is but it will start re-routing requests to the new shards. The new shards will have as many replicas as the original shard. A soft commit is automatically issued after splitting a shard so that documents are made visible on sub-shards. An explicit commit (hard or soft) is not necessary after a split operation because the index is automatically persisted to disk during the split operation.

This command allows for seamless splitting and requires no downtime. A shard being split will continue to accept query and indexing requests and will automatically start routing requests to the new shards once this operation is complete. This command can only be used for SolrCloud collections created with `numShards` parameter, meaning collections which rely on Solr's hash-based routing mechanism.

The split is performed by dividing the original shard's hash range into two equal partitions and dividing up the documents in the original shard according to the new sub-ranges. Two parameters discussed below, `ranges` and `split.key` provide further control over how the split occurs.

The newly created shards will have as many replicas as the parent shard, of the same replica types.

When using `splitMethod=rewrite` (default) you must ensure that the node running the leader of the parent shard has enough free disk space i.e., more than twice the index size, for the split to succeed. The API uses the Autoscaling framework to find nodes that can satisfy the disk requirements for the new replicas but only when an Autoscaling policy is configured. Refer to <<solrcloud-autoscaling-policy-preferences.adoc#solrcloud-autoscaling-policy-preferences,Autoscaling Policy and Preferences>> section for more details.

Also, the first replicas of resulting sub-shards will always be placed on the shard leader node, which may cause Autoscaling policy violations that need to be resolved either automatically (when appropriate triggers are in use) or manually.

Shard splitting can be a long running process. In order to avoid timeouts, you should run this as an <<Asynchronous Calls,asynchronous call>>.

=== SPLITSHARD Parameters

`collection`::
The name of the collection that includes the shard to be split. This parameter is required.

`shard`::
The name of the shard to be split. This parameter is required when `split.key` is not specified.

`ranges`::
A comma-separated list of hash ranges in hexadecimal, such as `ranges=0-1f4,1f5-3e8,3e9-5dc`.
+
This parameter can be used to divide the original shard's hash range into arbitrary hash range intervals specified in hexadecimal. For example, if the original hash range is `0-1500` then adding the parameter: `ranges=0-1f4,1f5-3e8,3e9-5dc` will divide the original shard into three shards with hash range `0-500`, `501-1000`, and `1001-1500` respectively.

`split.key`::
The key to use for splitting the index.
+
This parameter can be used to split a shard using a route key such that all documents of the specified route key end up in a single dedicated sub-shard. Providing the `shard` parameter is not required in this case because the route key is enough to figure out the right shard. A route key which spans more than one shard is not supported.
+
For example, suppose `split.key=A!` hashes to the range `12-15` and belongs to shard 'shard1' with range `0-20`. Splitting by this route key would yield three sub-shards with ranges `0-11`, `12-15` and `16-20`. Note that the sub-shard with the hash range of the route key may also contain documents for other route keys whose hash ranges overlap.

`numSubShards`::
The number of sub-shards to split the parent shard into. Allowed values for this are in the range of `2`-`8` and defaults to `2`.
+
This parameter can only be used when `ranges` or `split.key` are not specified.

`splitMethod`::
Currently two methods of shard splitting are supported:
* `splitMethod=rewrite` (default) after selecting documents to retain in each partition this method creates sub-indexes from
scratch, which is a lengthy CPU- and I/O-intensive process but results in optimally-sized sub-indexes that don't contain
any data from documents not belonging to each partition.
* `splitMethod=link` uses file system-level hard links for creating copies of the original index files and then only modifies the
file that contains the list of deleted documents in each partition. This method is many times quicker and lighter on resources than the
`rewrite` method but the resulting sub-indexes are still as large as the original index because they still contain data from documents not
belonging to the partition. This slows down the replication process and consumes more disk space on replica nodes (the multiple hard-linked
copies don't occupy additional disk space on the leader node, unless hard-linking is not supported).

`splitFuzz`::
A float value (default is 0.0f, must be smaller than 0.5f) that allows to vary the sub-shard ranges
by this percentage of total shard range, odd shards being larger and even shards being smaller.

`property._name_=_value_`::
Set core property _name_ to _value_. See the section <<defining-core-properties.adoc#defining-core-properties,Defining core.properties>> for details on supported properties and values.

`waitForFinalState`::
If `true`, the request will complete only when all affected replicas become active. The default is `false`, which means that the API will return the status of the single action, which may be before the new replica is online and active.

`timing`::
If `true` then each stage of processing will be timed and a `timing` section will be included in response.

`async`::
Request ID to track this action which will be <<Asynchronous Calls,processed asynchronously>>

=== SPLITSHARD Response

The output will include the status of the request and the new shard names, which will use the original shard as their basis, adding an underscore and a number. For example, "shard1" will become "shard1_0" and "shard1_1". If the status is anything other than "success", an error message will explain why the request failed.

=== Examples using SPLITSHARD

*Input*

Split shard1 of the "anotherCollection" collection.

[source,text]
----
http://localhost:8983/solr/admin/collections?action=SPLITSHARD&collection=anotherCollection&shard=shard1&wt=xml
----

*Output*

[source,xml]
----
<response>
  <lst name="responseHeader">
    <int name="status">0</int>
    <int name="QTime">6120</int>
  </lst>
  <lst name="success">
    <lst>
      <lst name="responseHeader">
        <int name="status">0</int>
        <int name="QTime">3673</int>
      </lst>
      <str name="core">anotherCollection_shard1_1_replica1</str>
    </lst>
    <lst>
      <lst name="responseHeader">
        <int name="status">0</int>
        <int name="QTime">3681</int>
      </lst>
      <str name="core">anotherCollection_shard1_0_replica1</str>
    </lst>
    <lst>
      <lst name="responseHeader">
        <int name="status">0</int>
        <int name="QTime">6008</int>
      </lst>
    </lst>
    <lst>
      <lst name="responseHeader">
        <int name="status">0</int>
        <int name="QTime">6007</int>
      </lst>
    </lst>
    <lst>
      <lst name="responseHeader">
        <int name="status">0</int>
        <int name="QTime">71</int>
      </lst>
    </lst>
    <lst>
      <lst name="responseHeader">
        <int name="status">0</int>
        <int name="QTime">0</int>
      </lst>
      <str name="core">anotherCollection_shard1_1_replica1</str>
      <str name="status">EMPTY_BUFFER</str>
    </lst>
    <lst>
      <lst name="responseHeader">
        <int name="status">0</int>
        <int name="QTime">0</int>
      </lst>
      <str name="core">anotherCollection_shard1_0_replica1</str>
      <str name="status">EMPTY_BUFFER</str>
    </lst>
  </lst>
</response>
----

[[createshard]]
== CREATESHARD: Create a Shard

Shards can only created with this API for collections that use the 'implicit' router (i.e., when the collection was created, `router.name=implicit`). A new shard with a name can be created for an existing 'implicit' collection.

Use SPLITSHARD for collections created with the 'compositeId' router (`router.key=compositeId`).

`/admin/collections?action=CREATESHARD&shard=_shardName_&collection=_name_`

The default values for `replicationFactor` or `nrtReplicas`, `tlogReplicas`, `pullReplicas` from the collection is used to determine the number of replicas to be created for the new shard. This can be customized by explicitly passing the corresponding parameters to the request.

The API uses the Autoscaling framework to find the best possible nodes in the cluster when an Autoscaling preferences or policy is configured. Refer to <<solrcloud-autoscaling-policy-preferences.adoc#solrcloud-autoscaling-policy-preferences,Autoscaling Policy and Preferences>> section for more details.

=== CREATESHARD Parameters

`collection`::
The name of the collection that includes the shard to be split. This parameter is required.

`shard`::
The name of the shard to be created. This parameter is required.

`createNodeSet`::
Allows defining the nodes to spread the new collection across. If not provided, the CREATESHARD operation will create shard-replica spread across all live Solr nodes.
+
The format is a comma-separated list of node_names, such as `localhost:8983_solr,localhost:8984_solr,localhost:8985_solr`.

`nrtReplicas`::
The number of `nrt` replicas that should be created for the new shard (optional, the defaults for the collection is used if omitted)

`tlogReplicas`::
The number of `tlog` replicas that should be created for the new shard (optional, the defaults for the collection is used if omitted)

`pullReplicas`::
The number of `pull` replicas that should be created for the new shard (optional, the defaults for the collection is used if omitted)

`property._name_=_value_`::
Set core property _name_ to _value_. See the section <<defining-core-properties.adoc#defining-core-properties,Defining core.properties>> for details on supported properties and values.

`waitForFinalState`::
If `true`, the request will complete only when all affected replicas become active. The default is `false`, which means that the API will return the status of the single action, which may be before the new replica is online and active.

`async`::
Request ID to track this action which will be <<Asynchronous Calls,processed asynchronously>>.

=== CREATESHARD Response

The output will include the status of the request. If the status is anything other than "success", an error message will explain why the request failed.

=== Examples using CREATESHARD

*Input*

Create 'shard-z' for the "anImplicitCollection" collection.

[source,text]
----
http://localhost:8983/solr/admin/collections?action=CREATESHARD&collection=anImplicitCollection&shard=shard-z&wt=xml
----

*Output*

[source,xml]
----
<response>
  <lst name="responseHeader">
    <int name="status">0</int>
    <int name="QTime">558</int>
  </lst>
</response>
----

[[deleteshard]]
== DELETESHARD: Delete a Shard

Deleting a shard will unload all replicas of the shard, remove them from `clusterstate.json`, and (by default) delete the instanceDir and dataDir for each replica. It will only remove shards that are inactive, or which have no range given for custom sharding.

`/admin/collections?action=DELETESHARD&shard=_shardID_&collection=_name_`

=== DELETESHARD Parameters

`collection`::
The name of the collection that includes the shard to be deleted. This parameter is required.

`shard`::
The name of the shard to be deleted. This parameter is required.

`deleteInstanceDir`::
By default Solr will delete the entire instanceDir of each replica that is deleted. Set this to `false` to prevent the instance directory from being deleted.

`deleteDataDir`::
By default Solr will delete the dataDir of each replica that is deleted. Set this to `false` to prevent the data directory from being deleted.

`deleteIndex`::
By default Solr will delete the index of each replica that is deleted. Set this to `false` to prevent the index directory from being deleted.

`async`::
Request ID to track this action which will be <<Asynchronous Calls,processed asynchronously>>.

=== DELETESHARD Response

The output will include the status of the request. If the status is anything other than "success", an error message will explain why the request failed.

=== Examples using DELETESHARD

*Input*

Delete 'shard1' of the "anotherCollection" collection.

[source,text]
----
http://localhost:8983/solr/admin/collections?action=DELETESHARD&collection=anotherCollection&shard=shard1&wt=xml
----

*Output*

[source,xml]
----
<response>
  <lst name="responseHeader">
    <int name="status">0</int>
    <int name="QTime">558</int>
  </lst>
  <lst name="success">
    <lst name="10.0.1.4:8983_solr">
      <lst name="responseHeader">
        <int name="status">0</int>
        <int name="QTime">27</int>
      </lst>
    </lst>
  </lst>
</response>
----

[[createalias]]
== CREATEALIAS: Create or Modify an Alias for a Collection

The `CREATEALIAS` action will create a new alias pointing to one or more collections.
Aliases come in 2 flavors: standard and routed.

*Standard aliases* are simple:  CREATEALIAS registers the alias name with the names of one or more collections provided
  by the command.
If an existing alias exists, it is replaced/updated.
A standard alias can serve as a means to rename a collection, and can be used to atomically swap
which backing/underlying collection is "live" for various purposes.
When Solr searches an alias pointing to multiple collections, Solr will search all shards of all the collections as an
  aggregated whole.
While it is possible to send updates to an alias spanning multiple collections, standard aliases have no logic for
  distributing documents among the referenced collections so all updates will go to the first collection in the list.

`/admin/collections?action=CREATEALIAS&name=_name_&collections=_collectionlist_`

*Routed aliases* are aliases with additional capabilities to act as a kind of super-collection that route
  updates to the correct collection. Routing is data driven and may be based on a temporal field or on categories
  specified in a field (normally string based).
See <<aliases.adoc#routed-aliases,Routed Aliases>> for some important high-level information
  before getting started.

[source,text]
----
localhost:8983/solr/admin/collections?action=CREATEALIAS&name=timedata&router.start=NOW/DAY&router.field=evt_dt&router.name=time&router.interval=%2B1DAY&router.maxFutureMs=3600000&create-collection.collection.configName=myConfig&create-collection.numShards=2
----

If run on Jan 15, 2018, the above will create an time routed alias named timedata, that contains collections with names prefixed
with `timedata` and an initial collection named `timedata_2018_01_15` will be created immediately. Updates sent to this
alias with a (required) value in `evt_dt` that is before or after 2018-01-15 will be rejected, until the last 60
minutes of 2018-01-15. After 2018-01-15T23:00:00 documents for either 2018-01-15 or 2018-01-16 will be accepted.
As soon as the system receives a document for an allowable time window for which there is no collection it will
automatically create the next required collection (and potentially any intervening collections if `router.interval` is
smaller than `router.maxFutureMs`). Both the initial collection and any subsequent collections will be created using
the specified configset. All collection creation parameters other than `name` are allowed, prefixed
by `create-collection.`

This means that one could, for example, partition their collections by day, and within each daily collection route
the data to shards based on customer id. Such shards can be of any type (NRT, PULL or TLOG), and rule-based replica
placement strategies may also be used.

The values supplied in this command for collection creation will be retained
in alias properties, and can be verified by inspecting `aliases.json` in ZooKeeper.

NOTE: Presently only updates are routed and queries are distributed to all collections in the alias, but future
features may enable routing of the query to the single appropriate collection based on a special parameter or perhaps
a filter on the routed field.

=== CREATEALIAS Parameters

`name`::
The alias name to be created. This parameter is required. If the alias is to be routed it also functions
as a prefix for the names of the dependent collections that will be created. It must therefore adhere to normal
requirements for collection naming.

`async`::
Request ID to track this action which will be <<Asynchronous Calls,processed asynchronously>>.

==== Standard Alias Parameters

`collections`::
A comma-separated list of collections to be aliased. The collections must already exist in the cluster.
This parameter signals the creation of a standard alias. If it is present all routing parameters are
prohibited. If routing parameters are present this parameter is prohibited.

==== Routed Alias Parameters

Most routed alias parameters become _alias properties_ that can subsequently be inspected and <<aliasprop,modified>>.

`router.name`::
The type of routing to use. Presently only `time` and `category` are valid.  This parameter is required.

`router.field`::
The field to inspect to determine which underlying collection an incoming document should be routed to.
This field is required on all incoming documents.

`create-collection.*`::
The * wildcard can be replaced with any parameter from the <<create,CREATE>> command except `name`. All other fields
are identical in requirements and naming except that we insist that the configset be explicitly specified.
The configset must be created beforehand, either uploaded or copied and modified.
It's probably a bad idea to use "data driven" mode as schema mutations might happen concurrently leading to errors.

==== Time Routed Alias Parameters

`router.start`::
The start date/time of data for this time routed alias in Solr's standard date/time format (i.e., ISO-8601 or "NOW"
optionally with <<working-with-dates.adoc#date-math,date math>>).
+
The first collection created for the alias will be internally named after this value.
If a document is submitted with an earlier value for router.field then the earliest collection the alias points to then
it will yield an error since it can't be routed. This date/time MUST NOT have a milliseconds component other than 0.
Particularly, this means `NOW` will fail 999 times out of 1000, though `NOW/SECOND`, `NOW/MINUTE`, etc. will work
just fine. This parameter is required.

`TZ`::
The timezone to be used when evaluating any date math in router.start or router.interval. This is equivalent to the
same parameter supplied to search queries, but understand in this case it's persisted with most of the other parameters
as an alias property.
+
If GMT-4 is supplied for this value then a document dated 2018-01-14T21:00:00:01.2345Z would be stored in the
myAlias_2018-01-15_01 collection (assuming an interval of +1HOUR).
+
The default timezone is UTC.

`router.interval`::
A date math expression that will be appended to a timestamp to determine the next collection in the series.
Any date math expression that can be evaluated if appended to a timestamp of the form 2018-01-15T16:17:18 will
work here.
+
This parameter is required.

`router.maxFutureMs`::
The maximum milliseconds into the future that a document is allowed to have in `router.field` for it to be accepted
without error.  If there was no limit, than an erroneous value could trigger many collections to be created.
+
The default is 10 minutes.

`router.preemptiveCreateMath`::
A date math expression that results in early creation of new collections.
+
If a document arrives with a timestamp that is after the end time of the most recent collection minus this
interval, then the next (and only the next) collection will be created asynchronously. Without this setting, collections are created
synchronously when required by the document time stamp and thus block the flow of documents until the collection
is created (possibly several seconds). Preemptive creation reduces these hiccups. If set to enough time (perhaps
an hour or more) then if there are problems creating a collection, this window of time might be enough to take
corrective action. However after a successful preemptive creation,  the collection is consuming resources without
being used, and new documents will tend to be routed through it only to be routed elsewhere. Also, note that
router.autoDeleteAge is currently evaluated relative to the date of a newly created collection, and so you may
want to increase the delete age by the preemptive window amount so that the oldest collection isn't deleted too
soon. Note that it has to be possible to subtract the interval specified from a date, so if prepending a
minus sign creates invalid date math, this will cause an error. Also note that a document that is itself
destined for a collection that does not exist will still trigger synchronous creation up to that destination collection
but will not trigger additional async preemptive creation. Only one type of collection creation can happen
per document.
Example: `90MINUTES`.
+
This property is blank by default indicating just-in-time, synchronous creation of new collections.

`router.autoDeleteAge`::
A date math expression that results in the oldest collections getting deleted automatically.
+
The date math is relative to the timestamp of a newly created collection (typically close to the current time),
and thus this must produce an earlier time via rounding and/or subtracting.
Collections to be deleted must have a time range that is entirely before the computed age.
Collections are considered for deletion immediately prior to new collections getting created.
Example: `/DAY-90DAYS`.
+
The default is not to delete.

==== Category Routed Alias Parameters

`router.maxCardinality`::
The maximum number of categories allowed for this alias.
This setting safeguards against the inadvertent creation of an infinite number of collections in the event of bad data.

`router.mustMatch`::
A regular expression that the value of the field specified by `router.field` must match before a corresponding
collection will be created. Note that changing this setting after data has been added will not alter the data already
indexed. Any valid Java regular expression pattern may be specified. This expression is pre-compiled at the start of
each request so batching of updates is strongly recommended. Overly complex patterns will produce cpu
or garbage collecting overhead during indexing as determined by the JVM's implementation of regular expressions.

=== CREATEALIAS Response

The output will simply be a responseHeader with details of the time it took to process the request.
To confirm the creation of the alias, you can look in the Solr Admin UI, under the Cloud section and find the
`aliases.json` file. The initial collection for routed aliases should also be visible in various parts of the admin UI.

=== Examples using CREATEALIAS

*Input*

Create an alias named "testalias" and link it to the collections named "anotherCollection" and "testCollection".

// tag::createalias-simple-example[]

[source,text]
----
http://localhost:8983/solr/admin/collections?action=CREATEALIAS&name=testalias&collections=anotherCollection,testCollection&wt=xml
----

//end::createalias-simple-example[]

*Output*

[source,xml]
----
<response>
  <lst name="responseHeader">
    <int name="status">0</int>
    <int name="QTime">122</int>
  </lst>
</response>
----

*Input*

Create an alias named "myTimeData" for data beginning on `2018-01-15` in the UTC time zone and partitioning daily
based on the `evt_dt` field in the incoming documents. Data more than one hour beyond the latest (most recent)
partition is to be rejected and collections are created using a configset named "myConfig".

[source,text]
----
http://localhost:8983/solr/admin/collections?action=CREATEALIAS&name=myTimeData&router.start=NOW/DAY&router.field=evt_dt&router.name=time&router.interval=%2B1DAY&router.maxFutureMs=3600000&create-collection.collection.configName=myConfig&create-collection.numShards=2
----

*Output*

[source,xml]
----
<response>
  <lst name="responseHeader">
    <int name="status">0</int>
    <int name="QTime">1234</int>
  </lst>
</response>
----


*Input*

A somewhat contrived example demonstrating the <<v2-api.adoc#top-v2-api,V2 API>> usage and additional collection creation options.
Notice that the collection creation parameters follow the v2 API naming convention, not the v1 naming conventions.

[source,json]
----
POST /api/c
{
  "create-routed-alias" : {
    "name": "somethingTemporalThisWayComes",
    "router" : {
      "name": "time",
      "field": "evt_dt",
      "start":"NOW/MINUTE",
      "interval":"+2HOUR",
      "maxFutureMs":"14400000"
    },
    "create-collection" : {
      "config":"_default",
      "router": {
        "name":"implicit",
        "field":"foo_s"
      },
      "shards":"foo,bar,baz",
      "numShards": 3,
      "tlogReplicas":1,
      "pullReplicas":1,
      "maxShardsPerNode":2,
      "properties" : {
        "foobar":"bazbam"
      }
    }
  }
}
----

*Output*

[source,xml]
----
{
    "responseHeader": {
        "status": 0,
        "QTime": 1234
    }
}
----

[[listaliases]]
== LISTALIASES: List of all aliases in the cluster

`/admin/collections?action=LISTALIASES`

The LISTALIASES action does not take any parameters.

=== LISTALIASES Response

The output will contain a list of aliases with the corresponding collection names.

=== Examples using LISTALIASES

*Input*

List the existing aliases, requesting information as XML from Solr:

[source,text]
----
http://localhost:8983/solr/admin/collections?action=LISTALIASES&wt=xml
----

*Output*

[source,xml]
----
<response>
    <lst name="responseHeader">
        <int name="status">0</int>
        <int name="QTime">0</int>
    </lst>
    <lst name="aliases">
        <str name="testalias1">collection1</str>
        <str name="testalias2">collection1,collection2</str>
    </lst>
    <lst name="properties">
        <lst name="testalias1"/>
        <lst name="testalias2">
            <str name="someKey">someValue</str>
        </lst>
    </lst>
</response>
----

[[aliasprop]]
== ALIASPROP: Modify Alias Properties for a Collection

The `ALIASPROP` action modifies the properties (metadata) on an alias. If a key is set with a value that is empty it will be removed.

`/admin/collections?action=ALIASPROP&name=_name_&property.someKey=somevalue`

WARNING: This command allows you to revise any property. No alias specific validation is performed.
         Routed aliases may cease to function, function incorrectly or cause errors if property values
         are set carelessly.

=== ALIASPROP Parameters

`name`::
The alias name on which to set properties. This parameter is required.

`property.*`::
The name of the property to be modified replaces '*', the value for the parameter is passed as the value for the property.

`async`::
Request ID to track this action which will be <<Asynchronous Calls,processed asynchronously>>.

=== ALIASPROP Response

The output will simply be a responseHeader with details of the time it took to process the request.
To confirm the creation of the property or properties, you can look in the Solr Admin UI, under the Cloud section and
find the `aliases.json` file or use the LISTALIASES api command.

=== Examples using ALIASPROP

*Input*

For an alias named "testalias2" and set the value "someValue" for a property of "someKey" and "otherValue" for "otherKey".

[source,text]
----
http://localhost:8983/solr/admin/collections?action=ALIASPROP&name=testalias2&property.someKey=someValue&property.otherKey=otherValue&wt=xml
----

*Output*

[source,xml]
----
<response>
  <lst name="responseHeader">
    <int name="status">0</int>
    <int name="QTime">122</int>
  </lst>
</response>
----

[[deletealias]]
== DELETEALIAS: Delete a Collection Alias

`/admin/collections?action=DELETEALIAS&name=_name_`

=== DELETEALIAS Parameters

`name`::
The name of the alias to delete. This parameter is required.

`async`::
Request ID to track this action which will be <<Asynchronous Calls,processed asynchronously>>.

=== DELETEALIAS Response

The output will simply be a responseHeader with details of the time it took to process the request.
To confirm the removal of the alias, you can look in the Solr Admin UI, under the Cloud section, and
find the `aliases.json` file.

=== Examples using DELETEALIAS

*Input*

Remove the alias named "testalias".

[source,text]
----
http://localhost:8983/solr/admin/collections?action=DELETEALIAS&name=testalias&wt=xml
----

*Output*

[source,xml]
----
<response>
  <lst name="responseHeader">
    <int name="status">0</int>
    <int name="QTime">117</int>
  </lst>
</response>
----

[[delete]]
== DELETE: Delete a Collection

`/admin/collections?action=DELETE&name=_collection_`

=== DELETE Parameters

`name`::
The name of the collection to delete. This parameter is required.

`async`::
Request ID to track this action which will be <<Asynchronous Calls,processed asynchronously>>.

=== DELETE Response

The response will include the status of the request and the cores that were deleted. If the status is anything other than "success", an error message will explain why the request failed.

=== Examples using DELETE

*Input*

Delete the collection named "newCollection".

[source,text]
----
http://localhost:8983/solr/admin/collections?action=DELETE&name=newCollection&wt=xml
----

*Output*

[source,xml]
----
<response>
  <lst name="responseHeader">
    <int name="status">0</int>
    <int name="QTime">603</int>
  </lst>
  <lst name="success">
    <lst name="10.0.1.6:8983_solr">
      <lst name="responseHeader">
        <int name="status">0</int>
        <int name="QTime">19</int>
      </lst>
    </lst>
    <lst name="10.0.1.4:8983_solr">
      <lst name="responseHeader">
        <int name="status">0</int>
        <int name="QTime">67</int>
      </lst>
    </lst>
  </lst>
</response>
----

[[deletereplica]]
== DELETEREPLICA: Delete a Replica

Deletes a named replica from the specified collection and shard.

If the corresponding core is up and running the core is unloaded, the entry is removed from the clusterstate, and (by default) delete the instanceDir and dataDir. If the node/core is down, the entry is taken off the clusterstate and if the core comes up later it is automatically unregistered.

`/admin/collections?action=DELETEREPLICA&collection=_collection_&shard=_shard_&replica=_replica_`

=== DELETEREPLICA Parameters

`collection`::
The name of the collection. This parameter is required.

`shard`::
The name of the shard that includes the replica to be removed. This parameter is required.

`replica`::
The name of the replica to remove.
+
If `count` is used instead, this parameter is not required. Otherwise, this parameter must be supplied.

`count`::
The number of replicas to remove. If the requested number exceeds the number of replicas, no replicas will be deleted. If there is only one replica, it will not be removed.
+
If `replica` is used instead, this parameter is not required. Otherwise, this parameter must be supplied.

`deleteInstanceDir`::
By default Solr will delete the entire instanceDir of the replica that is deleted. Set this to `false` to prevent the instance directory from being deleted.

`deleteDataDir`::
By default Solr will delete the dataDir of the replica that is deleted. Set this to `false` to prevent the data directory from being deleted.

`deleteIndex`::
By default Solr will delete the index of the replica that is deleted. Set this to `false` to prevent the index directory from being deleted.

`onlyIfDown`::
When set to `true`, no action will be taken if the replica is active. Default `false`.

`async`::
Request ID to track this action which will be <<Asynchronous Calls,processed asynchronously>>.

=== Examples using DELETEREPLICA

*Input*

[source,text]
----
http://localhost:8983/solr/admin/collections?action=DELETEREPLICA&collection=test2&shard=shard2&replica=core_node3&wt=xml
----

*Output*

[source,xml]
----
<response>
  <lst name="responseHeader">
    <int name="status">0</int>
    <int name="QTime">110</int>
  </lst>
</response>
----

[[addreplica]]
== ADDREPLICA: Add Replica

Add one or more replicas to a shard in a collection. The node name can be specified if the replica is to be created in a specific node. Otherwise, a set of nodes can be specified and the most suitable ones among them will be chosen to create the replica(s).

The API uses the Autoscaling framework to find nodes that can satisfy the disk requirements for the new replica(s) but only when an Autoscaling preferences or policy is configured. Refer to <<solrcloud-autoscaling-policy-preferences.adoc#solrcloud-autoscaling-policy-preferences,Autoscaling Policy and Preferences>> section for more details.

`/admin/collections?action=ADDREPLICA&collection=_collection_&shard=_shard_&node=_nodeName_`

=== ADDREPLICA Parameters

`collection`::
The name of the collection where the replica should be created. This parameter is required.

`shard`::
The name of the shard to which replica is to be added.
+
If `shard` is not specified, then `\_route_` must be.

`\_route_`::
If the exact shard name is not known, users may pass the `\_route_` value and the system would identify the name of the shard.
+
Ignored if the `shard` parameter is also specified.

`node`::
The name of the node where the replica should be created (optional).

`createNodeSet`::
A comma-separated list of nodes among which the best ones will be chosen to place the replicas (optional)
+
The format is a comma-separated list of node_names, such as `localhost:8983_solr,localhost:8984_solr,localhost:8985_solr`.

NOTE: If neither `node` nor `createNodeSet` are specified then the best node(s) from among all the live nodes in the cluster are chosen.

`instanceDir`::
The instanceDir for the core that will be created.

`dataDir`::
The directory in which the core should be created.

`type`::
The type of replica to create. These possible values are allowed:
+
* `nrt`: The NRT type maintains a transaction log and updates its index locally. This is the default and the most commonly used.
* `tlog`: The TLOG type maintains a transaction log but only updates its index via replication.
* `pull`: The PULL type does not maintain a transaction log and only updates its index via replication. This type is not eligible to become a leader.
+
See the section <<shards-and-indexing-data-in-solrcloud.adoc#types-of-replicas,Types of Replicas>> for more information about replica type options.

`nrtReplicas`::
The number of `nrt` replicas that should be created (optional, defaults to 1 if `type` is `nrt` otherwise 0).

`tlogReplicas`::
The number of `tlog` replicas that should be created (optional, defaults to 1 if `type` is `tlog` otherwise 0).

`pullReplicas`::
The number of `pull` replicas that should be created (optional, defaults to 1 if `type` is `pull` otherwise 0).

`property._name_=_value_`::
Set core property _name_ to _value_. See <<defining-core-properties.adoc#defining-core-properties,Defining core.properties>> for details about supported properties and values.

`waitForFinalState`::
If `true`, the request will complete only when all affected replicas become active. The default is `false`, which means that the API will return the status of the single action, which may be before the new replica is online and active.

`async`::
Request ID to track this action which will be <<Asynchronous Calls,processed asynchronously>>

=== Examples using ADDREPLICA

*Input*

Create a replica for the "test" collection on the node "192.167.1.2:8983_solr".

[source,text]
----
http://localhost:8983/solr/admin/collections?action=ADDREPLICA&collection=test2&shard=shard2&node=192.167.1.2:8983_solr&wt=xml
----

*Output*

[source,xml]
----
<response>
  <lst name="responseHeader">
    <int name="status">0</int>
    <int name="QTime">3764</int>
  </lst>
  <lst name="success">
    <lst>
      <lst name="responseHeader">
        <int name="status">0</int>
        <int name="QTime">3450</int>
      </lst>
      <str name="core">test2_shard2_replica4</str>
    </lst>
  </lst>
</response>
----

*Input*

Create a replica for the "gettingstarted" collection with one PULL replica and one TLOG replica.

[source,text]
----
http://localhost:8983/solr/admin/collections?action=addreplica&collection=gettingstarted&shard=shard1&tlogReplicas=1&pullReplicas=1
----

*Output*

[source,json]
----
{
    "responseHeader": {
        "status": 0,
        "QTime": 784
    },
    "success": {
        "127.0.1.1:7574_solr": {
            "responseHeader": {
                "status": 0,
                "QTime": 257
            },
            "core": "gettingstarted_shard1_replica_p11"
        },
        "127.0.1.1:8983_solr": {
            "responseHeader": {
                "status": 0,
                "QTime": 295
            },
            "core": "gettingstarted_shard1_replica_t10"
        }
    }
}
----

[[clusterprop]]
== CLUSTERPROP: Cluster Properties

Add, edit or delete a cluster-wide property.

`/admin/collections?action=CLUSTERPROP&name=_propertyName_&val=_propertyValue_`

=== CLUSTERPROP Parameters

`name`::
The name of the property. Supported properties names are `autoAddReplicas`, `legacyCloud` , `location`, `maxCoresPerNode` and `urlScheme`. Other properties can be set
(for example, if you need them for custom plugins) but they must begin with the prefix `ext.`. Unknown properties that don't begin with `ext.` will be rejected.

`val`::
The value of the property. If the value is empty or null, the property is unset.

=== CLUSTERPROP Response

The response will include the status of the request and the properties that were updated or removed. If the status is anything other than "0", an error message will explain why the request failed.

=== Examples using CLUSTERPROP

*Input*

[source,text]
----
http://localhost:8983/solr/admin/collections?action=CLUSTERPROP&name=urlScheme&val=https&wt=xml
----

*Output*

[source,xml]
----
<response>
  <lst name="responseHeader">
    <int name="status">0</int>
    <int name="QTime">0</int>
  </lst>
</response>
----

=== Setting Cluster-Wide Defaults

It is possible to set cluster-wide default values for certain attributes of a collection, using the `defaults` parameter.

*Set/update default values*
[source]
----
curl -X POST -H 'Content-type:application/json' --data-binary '
{
  "set-obj-property": {
    "defaults" : {
      "collection": {
        "numShards": 2,
        "nrtReplicas": 1,
        "tlogReplicas": 1,
        "pullReplicas": 1
      }
    }
  }
}' http://localhost:8983/api/cluster
----

*Unset the only value of `nrtReplicas`*
[source]
----
curl -X POST -H 'Content-type:application/json' --data-binary '
{
  "set-obj-property": {
    "defaults" : {
      "collection": {
        "nrtReplicas": null
      }
    }
  }
}' http://localhost:8983/api/cluster
----

*Unset all values in `defaults`*
[source]
----
curl -X POST -H 'Content-type:application/json' --data-binary '
{ "set-obj-property" : {
    "defaults" : null
}' http://localhost:8983/api/cluster
----

NOTE: Until Solr 7.5, cluster properties supported a `collectionDefaults` key which is now deprecated and
replaced with `defaults`. Using the `collectionDefaults` parameter in Solr 7.4 or 7.5 will continue to work
 but the format of the properties will automatically be converted to the new nested structure.
Support for the "collectionDefaults" key will be removed in Solr 9.

[[collectionprop]]
== COLLECTIONPROP: Collection Properties

Add, edit or delete a collection property.

`/admin/collections?action=COLLECTIONPROP&name=_collectionName_&propertyName=_propertyName_&propertyValue=_propertyValue_`

=== COLLECTIONPROP Parameters

`name`::
The name of the collection for which the property would be set.

`propertyName`::
The name of the property.

`propertyValue`::
The value of the property. When not provided, the property is deleted.

=== COLLECTIONPROP Response

The response will include the status of the request and the properties that were updated or removed. If the status is anything other than "0", an error message will explain why the request failed.

=== Examples using COLLECTIONPROP

*Input*

[source,text]
----
http://localhost:8983/solr/admin/collections?action=COLLECTIONPROP&name=coll&propertyName=foo&propertyValue=bar&wt=xml
----

*Output*

[source,xml]
----
<response>
  <lst name="responseHeader">
    <int name="status">0</int>
    <int name="QTime">0</int>
  </lst>
</response>
----

[[colstatus]]
== COLSTATUS: Detailed low-level status of collection's indexes
The COLSTATUS command provides a detailed description of the collection status, including low-level index
information about segments and field data.

This command also checks the compliance of Lucene index field types with the current Solr collection
schema and indicates the names of non-compliant fields, ie. Lucene fields with field types incompatible
(or different) from the corresponding Solr field types declared in the current schema. Such incompatibilities may
result from incompatible schema changes or after migration of
data to a different major Solr release.

`/admin/collections?action=COLSTATUS&collection=coll&coreInfo=true&segments=true&fieldInfo=true&sizeInfo=true`

=== COLSTATUS Parameters

`collection`::
Collection name (optional). If missing then it means all collections.

`coreInfo`::
Optional boolean. If true then additional information will be provided about
SolrCore of shard leaders.

`segments`::
Optional boolean. If true then segment information will be provided.

`fieldInfo`::
Optional boolean. If true then detailed Lucene field information will be provided
and their corresponding Solr schema types.

`sizeInfo`::
Optional boolean. If true then additional information about the index files
size and their RAM usage will be provided.

=== COLSTATUS Response
The response will include an overview of the collection status, the number of
active / inactive shards and replicas, and additional index information
of shard leaders.

=== Examples using COLSTATUS

*Input*

[source,text]
----
http://localhost:8983/solr/admin/collections?action=COLSTATUS&collection=gettingstarted&fieldInfo=true&sizeInfo=true
----

*Output*

[source,json]
----
{
    "responseHeader": {
        "status": 0,
        "QTime": 50
    },
    "gettingstarted": {
        "stateFormat": 2,
        "znodeVersion": 16,
        "properties": {
            "autoAddReplicas": "false",
            "maxShardsPerNode": "-1",
            "nrtReplicas": "2",
            "pullReplicas": "0",
            "replicationFactor": "2",
            "router": {
                "name": "compositeId"
            },
            "tlogReplicas": "0"
        },
        "activeShards": 2,
        "inactiveShards": 0,
        "schemaNonCompliant": [
            "(NONE)"
        ],
        "shards": {
            "shard1": {
                "state": "active",
                "range": "80000000-ffffffff",
                "replicas": {
                    "total": 2,
                    "active": 2,
                    "down": 0,
                    "recovering": 0,
                    "recovery_failed": 0
                },
                "leader": {
                    "coreNode": "core_node4",
                    "core": "gettingstarted_shard1_replica_n1",
                    "base_url": "http://192.168.0.80:8983/solr",
                    "node_name": "192.168.0.80:8983_solr",
                    "state": "active",
                    "type": "NRT",
                    "force_set_state": "false",
                    "leader": "true",
                    "segInfos": {
                        "info": {
                            "minSegmentLuceneVersion": "9.0.0",
                            "commitLuceneVersion": "9.0.0",
                            "numSegments": 40,
                            "segmentsFileName": "segments_w",
                            "totalMaxDoc": 686953,
                            "userData": {
                                "commitCommandVer": "1627350608019193856",
                                "commitTimeMSec": "1551962478819"
                            }
                        },
                        "fieldInfoLegend": [
                            "I - Indexed",
                            "D - DocValues",
                            "xxx - DocValues type",
                            "V - TermVector Stored",
                            "O - Omit Norms",
                            "F - Omit Term Frequencies & Positions",
                            "P - Omit Positions",
                            "H - Store Offsets with Positions",
                            "p - field has payloads",
                            "s - field uses soft deletes",
                            ":x:x:x - point data dim : index dim : num bytes"
                        ],
                        "segments": {
                            "_i": {
                                "name": "_i",
                                "delCount": 738,
                                "softDelCount": 0,
                                "hasFieldUpdates": false,
                                "sizeInBytes": 109398213,
                                "size": 70958,
                                "age": "2019-03-07T12:34:24.761Z",
                                "source": "merge",
                                "version": "9.0.0",
                                "createdVersionMajor": 9,
                                "minVersion": "9.0.0",
                                "diagnostics": {
                                    "os": "Mac OS X",
                                    "java.vendor": "Oracle Corporation",
                                    "java.version": "1.8.0_191",
                                    "java.vm.version": "25.191-b12",
                                    "lucene.version": "9.0.0",
                                    "mergeMaxNumSegments": "-1",
                                    "os.arch": "x86_64",
                                    "java.runtime.version": "1.8.0_191-b12",
                                    "source": "merge",
                                    "mergeFactor": "10",
                                    "os.version": "10.14.3",
                                    "timestamp": "1551962064761"
                                },
                                "attributes": {
                                    "Lucene50StoredFieldsFormat.mode": "BEST_SPEED"
                                },
                                "largestFiles": {
                                    "_i.fdt": "42.5 MB",
                                    "_i_Lucene80_0.dvd": "35.3 MB",
                                    "_i_Lucene50_0.pos": "11.1 MB",
                                    "_i_Lucene50_0.doc": "10 MB",
                                    "_i_Lucene50_0.tim": "4.3 MB"
                                },
                                "ramBytesUsed": {
                                    "total": 49153,
                                    "postings [PerFieldPostings(segment=_i formats=1)]": {
                                        "total": 31023,
...
                                "fields": {
                                    "dc": {
                                        "flags": "I-----------",
                                        "schemaType": "text_general"
                                    },
                                    "dc_str": {
                                        "flags": "-Dsrs-------",
                                        "schemaType": "strings"
                                    },
                                    "dc.title": {
                                        "flags": "I-----------",
                                        "docCount": 70958,
                                        "sumDocFreq": 646756,
                                        "sumTotalTermFreq": 671817,
                                        "schemaType": "text_general"
                                    },
                                    "dc.date": {
                                        "flags": "-Dsrn-------:1:1:8",
                                        "schemaType": "pdates"
                                    },
...
----


[[migrate]]
== MIGRATE: Migrate Documents to Another Collection

`/admin/collections?action=MIGRATE&collection=_name_&split.key=_key1!_&target.collection=_target_collection_&forward.timeout=60`

The MIGRATE command is used to migrate all documents having a given routing key to another collection. The source collection will continue to have the same data as-is but it will start re-routing write requests to the target collection for the number of seconds specified by the `forward.timeout` parameter. It is the responsibility of the user to switch to the target collection for reads and writes after the MIGRATE action completes.

The routing key specified by the `split.key` parameter may span multiple shards on both the source and the target collections. The migration is performed shard-by-shard in a single thread. One or more temporary collections may be created by this command during the ‘migrate’ process but they are cleaned up at the end automatically.

This is a long running operation and therefore using the `async` parameter is highly recommended. If the `async` parameter is not specified then the operation is synchronous by default and keeping a large read timeout on the invocation is advised. Even with a large read timeout, the request may still timeout but that doesn’t necessarily mean that the operation has failed. Users should check logs, cluster state, source and target collections before invoking the operation again.

This command works only with collections using the compositeId router. The target collection must not receive any writes during the time the MIGRATE command is running otherwise some writes may be lost.

Please note that the MIGRATE API does not perform any de-duplication on the documents so if the target collection contains documents with the same uniqueKey as the documents being migrated then the target collection will end up with duplicate documents.

=== MIGRATE Parameters

`collection`::
The name of the source collection from which documents will be split. This parameter is required.

`target.collection`::
The name of the target collection to which documents will be migrated. This parameter is required.

`split.key`::
The routing key prefix. For example, if the uniqueKey of a document is "a!123", then you would use `split.key=a!`. This parameter is required.

`forward.timeout`::
The timeout, in seconds, until which write requests made to the source collection for the given `split.key` will be forwarded to the target shard. The default is 60 seconds.

`property._name_=_value_`::
Set core property _name_ to _value_. See the section <<defining-core-properties.adoc#defining-core-properties,Defining core.properties>> for details on supported properties and values.

`async`::
Request ID to track this action which will be <<Asynchronous Calls,processed asynchronously>>.

=== MIGRATE Response

The response will include the status of the request.

=== Examples using MIGRATE

*Input*

[source,text]
----
http://localhost:8983/solr/admin/collections?action=MIGRATE&collection=test1&split.key=a!&target.collection=test2&wt=xml
----

*Output*

[source,xml]
----
<response>
  <lst name="responseHeader">
    <int name="status">0</int>
    <int name="QTime">19014</int>
  </lst>
  <lst name="success">
    <lst>
      <lst name="responseHeader">
        <int name="status">0</int>
        <int name="QTime">1</int>
      </lst>
      <str name="core">test2_shard1_0_replica1</str>
      <str name="status">BUFFERING</str>
    </lst>
    <lst>
      <lst name="responseHeader">
        <int name="status">0</int>
        <int name="QTime">2479</int>
      </lst>
      <str name="core">split_shard1_0_temp_shard1_0_shard1_replica1</str>
    </lst>
    <lst>
      <lst name="responseHeader">
        <int name="status">0</int>
        <int name="QTime">1002</int>
      </lst>
    </lst>
    <lst>
      <lst name="responseHeader">
        <int name="status">0</int>
        <int name="QTime">21</int>
      </lst>
    </lst>
    <lst>
      <lst name="responseHeader">
        <int name="status">0</int>
        <int name="QTime">1655</int>
      </lst>
      <str name="core">split_shard1_0_temp_shard1_0_shard1_replica2</str>
    </lst>
    <lst>
      <lst name="responseHeader">
        <int name="status">0</int>
        <int name="QTime">4006</int>
      </lst>
    </lst>
    <lst>
      <lst name="responseHeader">
        <int name="status">0</int>
        <int name="QTime">17</int>
      </lst>
    </lst>
    <lst>
      <lst name="responseHeader">
        <int name="status">0</int>
        <int name="QTime">1</int>
      </lst>
      <str name="core">test2_shard1_0_replica1</str>
      <str name="status">EMPTY_BUFFER</str>
    </lst>
    <lst name="192.168.43.52:8983_solr">
      <lst name="responseHeader">
        <int name="status">0</int>
        <int name="QTime">31</int>
      </lst>
    </lst>
    <lst name="192.168.43.52:8983_solr">
      <lst name="responseHeader">
        <int name="status">0</int>
        <int name="QTime">31</int>
      </lst>
    </lst>
    <lst>
      <lst name="responseHeader">
        <int name="status">0</int>
        <int name="QTime">1</int>
      </lst>
      <str name="core">test2_shard1_1_replica1</str>
      <str name="status">BUFFERING</str>
    </lst>
    <lst>
      <lst name="responseHeader">
        <int name="status">0</int>
        <int name="QTime">1742</int>
      </lst>
      <str name="core">split_shard1_1_temp_shard1_1_shard1_replica1</str>
    </lst>
    <lst>
      <lst name="responseHeader">
        <int name="status">0</int>
        <int name="QTime">1002</int>
      </lst>
    </lst>
    <lst>
      <lst name="responseHeader">
        <int name="status">0</int>
        <int name="QTime">15</int>
      </lst>
    </lst>
    <lst>
      <lst name="responseHeader">
        <int name="status">0</int>
        <int name="QTime">1917</int>
      </lst>
      <str name="core">split_shard1_1_temp_shard1_1_shard1_replica2</str>
    </lst>
    <lst>
      <lst name="responseHeader">
        <int name="status">0</int>
        <int name="QTime">5007</int>
      </lst>
    </lst>
    <lst>
      <lst name="responseHeader">
        <int name="status">0</int>
        <int name="QTime">8</int>
      </lst>
    </lst>
    <lst>
      <lst name="responseHeader">
        <int name="status">0</int>
        <int name="QTime">1</int>
      </lst>
      <str name="core">test2_shard1_1_replica1</str>
      <str name="status">EMPTY_BUFFER</str>
    </lst>
    <lst name="192.168.43.52:8983_solr">
      <lst name="responseHeader">
        <int name="status">0</int>
        <int name="QTime">30</int>
      </lst>
    </lst>
    <lst name="192.168.43.52:8983_solr">
      <lst name="responseHeader">
        <int name="status">0</int>
        <int name="QTime">30</int>
      </lst>
    </lst>
  </lst>
</response>
----

[[addrole]]
== ADDROLE: Add a Role

`/admin/collections?action=ADDROLE&role=_roleName_&node=_nodeName_`

Assigns a role to a given node in the cluster. The only supported role is `overseer`.

Use this command to dedicate a particular node as Overseer. Invoke it multiple times to add more nodes. This is useful in large clusters where an Overseer is likely to get overloaded. If available, one among the list of nodes which are assigned the 'overseer' role would become the overseer. The system would assign the role to any other node if none of the designated nodes are up and running.

=== ADDROLE Parameters

`role`::
The name of the role. The only supported role as of now is `overseer`. This parameter is required.

`node`::
The name of the node that will be assigned the role. It is possible to assign a role even before that node is started. This parameter is started.

=== ADDROLE Response

The response will include the status of the request and the properties that were updated or removed. If the status is anything other than "0", an error message will explain why the request failed.

=== Examples using ADDROLE

*Input*

[source,text]
----
http://localhost:8983/solr/admin/collections?action=ADDROLE&role=overseer&node=192.167.1.2:8983_solr&wt=xml
----

*Output*

[source,xml]
----
<response>
  <lst name="responseHeader">
    <int name="status">0</int>
    <int name="QTime">0</int>
  </lst>
</response>
----

[[removerole]]
== REMOVEROLE: Remove Role

Remove an assigned role. This API is used to undo the roles assigned using ADDROLE operation

`/admin/collections?action=REMOVEROLE&role=_roleName_&node=_nodeName_`

=== REMOVEROLE Parameters

`role`::
The name of the role. The only supported role as of now is `overseer`. This parameter is required.

`node`::
The name of the node where the role should be removed.


=== REMOVEROLE Response

The response will include the status of the request and the properties that were updated or removed. If the status is anything other than "0", an error message will explain why the request failed.

=== Examples using REMOVEROLE

*Input*

[source,text]
----
http://localhost:8983/solr/admin/collections?action=REMOVEROLE&role=overseer&node=192.167.1.2:8983_solr&wt=xml
----

*Output*

[source,xml]
----
<response>
  <lst name="responseHeader">
    <int name="status">0</int>
    <int name="QTime">0</int>
  </lst>
</response>
----

[[overseerstatus]]
== OVERSEERSTATUS: Overseer Status and Statistics

Returns the current status of the overseer, performance statistics of various overseer APIs, and the last 10 failures per operation type.

`/admin/collections?action=OVERSEERSTATUS`

=== Examples using OVERSEERSTATUS

*Input:*

[source,text]
----
http://localhost:8983/solr/admin/collections?action=OVERSEERSTATUS
----

[source,json]
----
{
  "responseHeader":{
    "status":0,
    "QTime":33},
  "leader":"127.0.1.1:8983_solr",
  "overseer_queue_size":0,
  "overseer_work_queue_size":0,
  "overseer_collection_queue_size":2,
  "overseer_operations":[
    "createcollection",{
      "requests":2,
      "errors":0,
      "avgRequestsPerSecond":0.7467088842794136,
      "5minRateRequestsPerSecond":7.525069023276674,
      "15minRateRequestsPerSecond":10.271274280947182,
      "avgTimePerRequest":0.5050685,
      "medianRequestTime":0.5050685,
      "75thPcRequestTime":0.519016,
      "95thPcRequestTime":0.519016,
      "99thPcRequestTime":0.519016,
      "999thPcRequestTime":0.519016},
    "removeshard",{
      "..."
  }],
  "collection_operations":[
    "splitshard",{
      "requests":1,
      "errors":1,
      "recent_failures":[{
          "request":{
            "operation":"splitshard",
            "shard":"shard2",
            "collection":"example1"},
          "response":[
            "Operation splitshard caused exception:","org.apache.solr.common.SolrException:org.apache.solr.common.SolrException: No shard with the specified name exists: shard2",
            "exception",{
              "msg":"No shard with the specified name exists: shard2",
              "rspCode":400}]}],
      "avgRequestsPerSecond":0.8198143044809885,
      "5minRateRequestsPerSecond":8.043840552427673,
      "15minRateRequestsPerSecond":10.502079828515368,
      "avgTimePerRequest":2952.7164175,
      "medianRequestTime":2952.7164175000003,
      "75thPcRequestTime":5904.384052,
      "95thPcRequestTime":5904.384052,
      "99thPcRequestTime":5904.384052,
      "999thPcRequestTime":5904.384052},
    "..."
  ],
  "overseer_queue":[
    "..."
  ],
  "..."
 }
----

[[clusterstatus]]
== CLUSTERSTATUS: Cluster Status

Fetch the cluster status including collections, shards, replicas, configuration name as well as collection aliases and cluster properties.

`/admin/collections?action=CLUSTERSTATUS`

=== CLUSTERSTATUS Parameters

`collection`::
The collection or alias name for which information is requested. If omitted, information on all collections in the cluster will be returned. If an alias is supplied, information on the collections in the alias will be returned.

`shard`::
The shard(s) for which information is requested. Multiple shard names can be specified as a comma-separated list.

`\_route_`::
This can be used if you need the details of the shard where a particular document belongs to and you don't know which shard it falls under.

=== CLUSTERSTATUS Response

The response will include the status of the request and the status of the cluster.

=== Examples using CLUSTERSTATUS

*Input*

[source,text]
----
http://localhost:8983/solr/admin/collections?action=CLUSTERSTATUS
----

*Output*

[source,json]
----
{
  "responseHeader":{
    "status":0,
    "QTime":333},
  "cluster":{
    "collections":{
      "collection1":{
        "shards":{
          "shard1":{
            "range":"80000000-ffffffff",
            "state":"active",
            "replicas":{
              "core_node1":{
                "state":"active",
                "core":"collection1",
                "node_name":"127.0.1.1:8983_solr",
                "base_url":"http://127.0.1.1:8983/solr",
                "leader":"true"},
              "core_node3":{
                "state":"active",
                "core":"collection1",
                "node_name":"127.0.1.1:8900_solr",
                "base_url":"http://127.0.1.1:8900/solr"}}},
          "shard2":{
            "range":"0-7fffffff",
            "state":"active",
            "replicas":{
              "core_node2":{
                "state":"active",
                "core":"collection1",
                "node_name":"127.0.1.1:7574_solr",
                "base_url":"http://127.0.1.1:7574/solr",
                "leader":"true"},
              "core_node4":{
                "state":"active",
                "core":"collection1",
                "node_name":"127.0.1.1:7500_solr",
                "base_url":"http://127.0.1.1:7500/solr"}}}},
        "maxShardsPerNode":"1",
        "router":{"name":"compositeId"},
        "replicationFactor":"1",
        "znodeVersion": 11,
        "autoCreated":"true",
        "configName" : "my_config",
        "aliases":["both_collections"]
      },
      "collection2":{
        "..."
      }
    },
    "aliases":{ "both_collections":"collection1,collection2" },
    "roles":{
      "overseer":[
        "127.0.1.1:8983_solr",
        "127.0.1.1:7574_solr"]
    },
    "live_nodes":[
      "127.0.1.1:7574_solr",
      "127.0.1.1:7500_solr",
      "127.0.1.1:8983_solr",
      "127.0.1.1:8900_solr"]
  }
}
----

[[requeststatus]]
== REQUESTSTATUS: Request Status of an Async Call

Request the status and response of an already submitted <<Asynchronous Calls,Asynchronous Collection API>> (below) call. This call is also used to clear up the stored statuses.

`/admin/collections?action=REQUESTSTATUS&requestid=_request-id_`

=== REQUESTSTATUS Parameters

`requestid`::
The user defined request ID for the request. This can be used to track the status of the submitted asynchronous task. This parameter is required.

=== Examples using REQUESTSTATUS

*Input: Valid Request ID*

[source,text]
----
http://localhost:8983/solr/admin/collections?action=REQUESTSTATUS&requestid=1000&wt=xml
----

*Output*

[source,xml]
----
<response>
  <lst name="responseHeader">
    <int name="status">0</int>
    <int name="QTime">1</int>
  </lst>
  <lst name="status">
    <str name="state">completed</str>
    <str name="msg">found 1000 in completed tasks</str>
  </lst>
</response>
----

*Input: Invalid Request ID*

[source,text]
----
http://localhost:8983/solr/admin/collections?action=REQUESTSTATUS&requestid=1004&wt=xml
----

*Output*

[source,xml]
----
<response>
  <lst name="responseHeader">
    <int name="status">0</int>
    <int name="QTime">1</int>
  </lst>
  <lst name="status">
    <str name="state">notfound</str>
    <str name="msg">Did not find taskid [1004] in any tasks queue</str>
  </lst>
</response>
----

[[deletestatus]]
== DELETESTATUS: Delete Status

Deletes the stored response of an already failed or completed <<Asynchronous Calls,Asynchronous Collection API>> call.

`/admin/collections?action=DELETESTATUS&requestid=_request-id_`

=== DELETESTATUS Parameters

`requestid`::
The request ID of the asynchronous call whose stored response should be cleared.

`flush`::
Set to `true` to clear all stored completed and failed async request responses.

=== Examples using DELETESTATUS

*Input: Valid Request ID*

[source,text]
----
http://localhost:8983/solr/admin/collections?action=DELETESTATUS&requestid=foo&wt=xml
----

*Output*

[source,xml]
----
<response>
  <lst name="responseHeader">
    <int name="status">0</int>
    <int name="QTime">1</int>
  </lst>
  <str name="status">successfully removed stored response for [foo]</str>
</response>
----

*Input: Invalid Request ID*

[source,text]
----
http://localhost:8983/solr/admin/collections?action=DELETESTATUS&requestid=bar&wt=xml
----

*Output*

[source,xml]
----
<response>
  <lst name="responseHeader">
    <int name="status">0</int>
    <int name="QTime">1</int>
  </lst>
  <str name="status">[bar] not found in stored responses</str>
</response>
----

*Input: Clear All Stored Statuses*

[source,text]
----
http://localhost:8983/solr/admin/collections?action=DELETESTATUS&flush=true&wt=xml
----

*Output*

[source,xml]
----
<response>
  <lst name="responseHeader">
    <int name="status">0</int>
    <int name="QTime">1</int>
  </lst>
  <str name="status"> successfully cleared stored collection api responses </str>
</response>
----

[[list]]
== LIST: List Collections

Fetch the names of the collections in the cluster.

`/admin/collections?action=LIST`

=== Examples using LIST

*Input*

[source,text]
----
http://localhost:8983/solr/admin/collections?action=LIST
----

*Output*

[source,json]
----
{
  "responseHeader":{
    "status":0,
    "QTime":2011},
  "collections":["collection1",
    "example1",
    "example2"]}
----

[[addreplicaprop]]
== ADDREPLICAPROP: Add Replica Property

Assign an arbitrary property to a particular replica and give it the value specified. If the property already exists, it will be overwritten with the new value.

`/admin/collections?action=ADDREPLICAPROP&collection=collectionName&shard=shardName&replica=replicaName&property=propertyName&property.value=value`

=== ADDREPLICAPROP Parameters

`collection`::
The name of the collection the replica belongs to. This parameter is required.

`shard`::
The name of the shard the replica belongs to. This parameter is required.

`replica`::
The replica, e.g., `core_node1`. This parameter is required.

`property`::
The name of the property to add. This property is required.
+
This will have the literal `property.` prepended to distinguish it from system-maintained properties. So these two forms are equivalent:
+
`property=special`
+
and
+
`property=property.special`

`property.value`::
The value to assign to the property. This parameter is required.

`shardUnique`::
If `true`, then setting this property in one replica will remove the property from all other replicas in that shard. The default is `false`.
+
There is one pre-defined property `preferredLeader` for which `shardUnique` is forced to `true` and an error returned if `shardUnique` is explicitly set to `false`.
+
`PreferredLeader` is a boolean property. Any value assigned that is not equal (case insensitive) to `true` will be interpreted as `false` for `preferredLeader`.

=== ADDREPLICAPROP Response

The response will include the status of the request. If the status is anything other than "0", an error message will explain why the request failed.

=== Examples using ADDREPLICAPROP

*Input*

This command would set the "preferredLeader" property (`property.preferredLeader`) to "true" on "core_node1", and remove that property from any other replica in the shard.

[source,text]
----
http://localhost:8983/solr/admin/collections?action=ADDREPLICAPROP&shard=shard1&collection=collection1&replica=core_node1&property=preferredLeader&property.value=true&wt=xml
----

*Output*

[source,xml]
----
<response>
  <lst name="responseHeader">
    <int name="status">0</int>
    <int name="QTime">46</int>
  </lst>
</response>
----

*Input*

This pair of commands will set the "testprop" property (`property.testprop`) to 'value1' and 'value2' respectively for two nodes in the same shard.

[source,text]
----
http://localhost:8983/solr/admin/collections?action=ADDREPLICAPROP&shard=shard1&collection=collection1&replica=core_node1&property=testprop&property.value=value1

http://localhost:8983/solr/admin/collections?action=ADDREPLICAPROP&shard=shard1&collection=collection1&replica=core_node3&property=property.testprop&property.value=value2
----

*Input*

This pair of commands would result in "core_node_3" having the "testprop" property (`property.testprop`) value set because the second command specifies `shardUnique=true`, which would cause the property to be removed from "core_node_1".

[source,text]
----
http://localhost:8983/solr/admin/collections?action=ADDREPLICAPROP&shard=shard1&collection=collection1&replica=core_node1&property=testprop&property.value=value1

http://localhost:8983/solr/admin/collections?action=ADDREPLICAPROP&shard=shard1&collection=collection1&replica=core_node3&property=testprop&property.value=value2&shardUnique=true
----

[[deletereplicaprop]]
== DELETEREPLICAPROP: Delete Replica Property

Deletes an arbitrary property from a particular replica.

`/admin/collections?action=DELETEREPLICAPROP&collection=collectionName&shard=_shardName_&replica=_replicaName_&property=_propertyName_`

=== DELETEREPLICAPROP Parameters

`collection`::
The name of the collection the replica belongs to. This parameter is required.

`shard`::
The name of the shard the replica belongs to. This parameter is required.

`replica`::
The replica, e.g., `core_node1`. This parameter is required.

`property`::
The property to add. This will have the literal `property.` prepended to distinguish it from system-maintained properties. So these two forms are equivalent:
+
`property=special`
+
and
+
`property=property.special`

=== DELETEREPLICAPROP Response

The response will include the status of the request. If the status is anything other than "0", an error message will explain why the request failed.

=== Examples using DELETEREPLICAPROP

*Input*

This command would delete the preferredLeader (`property.preferredLeader`) from core_node1.

[source,text]
----
http://localhost:8983/solr/admin/collections?action=DELETEREPLICAPROP&shard=shard1&collection=collection1&replica=core_node1&property=preferredLeader&wt=xml
----

*Output*

[source,xml]
----
<response>
  <lst name="responseHeader">
    <int name="status">0</int>
    <int name="QTime">9</int>
  </lst>
</response>
----

[[balanceshardunique]]
== BALANCESHARDUNIQUE: Balance a Property Across Nodes

`/admin/collections?action=BALANCESHARDUNIQUE&collection=_collectionName_&property=_propertyName_`

Insures that a particular property is distributed evenly amongst the physical nodes that make up a collection. If the property already exists on a replica, every effort is made to leave it there. If the property is *not* on any replica on a shard, one is chosen and the property is added.

=== BALANCESHARDUNIQUE Parameters

`collection`::
The name of the collection to balance the property in. This parameter is required.

`property`::
The property to balance. The literal `property.` is prepended to this property if not specified explicitly. This parameter is required.

`onlyactivenodes`::
Defaults to `true`. Normally, the property is instantiated on active nodes only. If this parameter is specified as `false`, then inactive nodes are also included for distribution.

`shardUnique`::
Something of a safety valve. There is one pre-defined property (`preferredLeader`) that defaults this value to `true`. For all other properties that are balanced, this must be set to `true` or an error message will be returned.

=== BALANCESHARDUNIQUE Response

The response will include the status of the request. If the status is anything other than "0", an error message will explain why the request failed.

=== Examples using BALANCESHARDUNIQUE

*Input*

Either of these commands would put the "preferredLeader" property on one replica in every shard in the "collection1" collection.

[source,text]
----
http://localhost:8983/solr/admin/collections?action=BALANCESHARDUNIQUE&collection=collection1&property=preferredLeader&wt=xml

http://localhost:8983/solr/admin/collections?action=BALANCESHARDUNIQUE&collection=collection1&property=property.preferredLeader&wt=xml
----

*Output*

[source,xml]
----
<response>
  <lst name="responseHeader">
    <int name="status">0</int>
    <int name="QTime">9</int>
  </lst>
</response>
----

Examining the clusterstate after issuing this call should show exactly one replica in each shard that has this property.

[[rebalanceleaders]]
== REBALANCELEADERS: Rebalance Leaders

Reassigns leaders in a collection according to the preferredLeader property across active nodes.

`/admin/collections?action=REBALANCELEADERS&collection=collectionName`

Leaders are assigned in a collection according to the `preferredLeader` property on active nodes. This command should be run after the preferredLeader property has been assigned via the BALANCESHARDUNIQUE or ADDREPLICAPROP commands.

NOTE: It is not _required_ that all shards in a collection have a `preferredLeader` property. Rebalancing will only attempt to reassign leadership to those replicas that have the `preferredLeader` property set to `true` _and_ are not currently the shard leader _and_ are currently active.

=== REBALANCELEADERS Parameters

`collection`::
The name of the collection to rebalance `preferredLeaders` on. This parameter is required.

`maxAtOnce`::
The maximum number of reassignments to have queue up at once. Values \<=0 are use the default value Integer.MAX_VALUE.
+
When this number is reached, the process waits for one or more leaders to be successfully assigned before adding more to the queue.

`maxWaitSeconds`::
Defaults to `60`. This is the timeout value when waiting for leaders to be reassigned. If `maxAtOnce` is less than the number of reassignments that will take place, this is the maximum interval that any _single_ wait for at least one reassignment.
+
For example, if 10 reassignments are to take place and `maxAtOnce` is `1` and `maxWaitSeconds` is `60`, the upper bound on the time that the command may wait is 10 minutes.

=== REBALANCELEADERS Response

The response will include the status of the request. A status of "0" indicates the request was _processed_, not that all assignments were successful. Examine the "Summary" section for that information.

=== Examples using REBALANCELEADERS

*Input*

Either of these commands would cause all the active replicas that had the `preferredLeader` property set and were _not_ already the preferred leader to become leaders.

[source,text]
----
http://localhost:8983/solr/admin/collections?action=REBALANCELEADERS&collection=collection1&wt=json

http://localhost:8983/solr/admin/collections?action=REBALANCELEADERS&collection=collection1&maxAtOnce=5&maxWaitSeconds=30&wt=json
----

*Output*

In this example:

* In the "alreadyLeaders" section, core_node5 was already the leader, so there were no changes in leadership for shard1.
* In the "inactivePreferreds" section, core_node57 had the preferredLeader property set, but the node was not active, the leader for shard7 was not changed. This is considered successful.
* In the "successes" section, core_node23 was _not_ the leader for shard3, so leadership was assigned to that replica.

The "Summary" section with the "Success" tag indicates that the command rebalanced all _active_ replicas with the preferredLeader property set as requried. If a replica cannot be made leader due to not being healthy (for example, it is on a Solr instance that is not running), it's also considered success.

[source,json]
----
{
  "responseHeader":{
    "status":0,
    "QTime":3054},
  "Summary":{
    "Success":"All active replicas with the preferredLeader property set are leaders"},
  "alreadyLeaders":{
    "core_node5":{
      "status":"skipped",
      "msg":"Replica core_node5 is already the leader for shard shard1. No change necessary"}},
  "inactivePreferreds":{
    "core_node57":{
      "status":"skipped",
      "msg":"Replica core_node57 is a referredLeader for shard shard7, but is inactive. No change necessary"}},
  "successes":{
    "shard3":{
      "status":"success",
      "msg":"Successfully changed leader of slice shard3 to core_node23"}}}
----

Examining the clusterstate after issuing this call should show that every active replica that has the `preferredLeader` property should also have the "leader" property set to _true_.

NOTE: The added work done by an NRT leader is quite small and only present when indexing. The primary use-case is to redistribute the leader role if there are a large number of leaders concentrated on a small number of nodes. Rebalancing will likely not improve performance unless the imbalance of leadership roles is measured in multiples of 10.

NOTE: The BALANCESHARDUNIQUE command that distributes the preferredLeader property does not guarantee perfect distribution and in some collection topologies it is impossible to make that guarantee.

[[forceleader]]
== FORCELEADER: Force Shard Leader

In the unlikely event of a shard losing its leader, this command can be invoked to force the election of a new leader.

`/admin/collections?action=FORCELEADER&collection=<collectionName>&shard=<shardName>`

=== FORCELEADER Parameters

`collection`::
The name of the collection. This parameter is required.

`shard`::
The name of the shard where leader election should occur. This parameter is required.

WARNING: This is an expert level command, and should be invoked only when regular leader election is not working. This may potentially lead to loss of data in the event that the new leader doesn't have certain updates, possibly recent ones, which were acknowledged by the old leader before going down.

[[migratestateformat]]
== MIGRATESTATEFORMAT: Migrate Cluster State

A expert level utility API to move a collection from shared `clusterstate.json` ZooKeeper node (created with `stateFormat=1`, the default in all Solr releases prior to 5.0) to the per-collection `state.json` stored in ZooKeeper (created with `stateFormat=2`, the current default) seamlessly without any application down-time.

`/admin/collections?action=MIGRATESTATEFORMAT&collection=<collection_name>`

=== MIGRATESTATEFORMAT Parameters

`collection`::
The name of the collection to be migrated from `clusterstate.json` to its own `state.json` ZooKeeper node. This parameter is required.

`async`::
Request ID to track this action which will be <<Asynchronous Calls,processed asynchronously>>.

This API is useful in migrating any collections created prior to Solr 5.0 to the more scalable cluster state format now used by default. If a collection was created in any Solr 5.x version or higher, then executing this command is not necessary.

[[backup]]
== BACKUP: Backup Collection

Backs up Solr collections and associated configurations to a shared filesystem - for example a Network File System.

`/admin/collections?action=BACKUP&name=myBackupName&collection=myCollectionName&location=/path/to/my/shared/drive`

The BACKUP command will backup Solr indexes and configurations for a specified collection. The BACKUP command takes one copy from each shard for the indexes. For configurations, it backs up the configSet that was associated with the collection and metadata.

=== BACKUP Parameters

`collection`::
The name of the collection to be backed up. This parameter is required.

`location`::
The location on a shared drive for the backup command to write to. Alternately it can be set as a <<clusterprop,cluster property>>.

`async`::
Request ID to track this action which will be <<Asynchronous Calls,processed asynchronously>>.

`repository`::
The name of a repository to be used for the backup. If no repository is specified then the local filesystem repository will be used automatically.

[[restore]]
== RESTORE: Restore Collection

Restores Solr indexes and associated configurations.

`/admin/collections?action=RESTORE&name=myBackupName&location=/path/to/my/shared/drive&collection=myRestoredCollectionName`

The RESTORE operation will create a collection with the specified name in the collection parameter. You cannot restore into the same collection the backup was taken from. Also the target collection should not be present at the time the API is called as Solr will create it for you.

The collection created will be have the same number of shards and replicas as the original collection, preserving routing information, etc. Optionally, you can override some parameters documented below.

While restoring, if a configSet with the same name exists in ZooKeeper then Solr will reuse that, or else it will upload the backed up configSet in ZooKeeper and use that.

You can use the collection <<createalias,CREATEALIAS>> command to make sure clients don't need to change the endpoint to query or index against the newly restored collection.

=== RESTORE Parameters

`collection`::
The collection where the indexes will be restored into. This parameter is required.

`location`::
The location on a shared drive for the RESTORE command to read from. Alternately it can be set as a <<clusterprop,cluster property>>.

`async`::
Request ID to track this action which will be <<Asynchronous Calls,processed asynchronously>>.

`repository`::
The name of a repository to be used for the backup. If no repository is specified then the local filesystem repository will be used automatically.

*Override Parameters*

Additionally, there are several parameters that may have been set on the original collection that can be overridden when restoring the backup:

`collection.configName`::
Defines the name of the configurations to use for this collection. These must already be stored in ZooKeeper. If not provided, Solr will default to the collection name as the configuration name.

`replicationFactor`::
The number of replicas to be created for each shard.

`nrtReplicas`::
The number of NRT (Near-Real-Time) replicas to create for this collection. This type of replica maintains a transaction log and updates its index locally. This parameter behaves the same way as setting replicationFactor parameter.

`tlogReplicas`::
The number of TLOG replicas to create for this collection. This type of replica maintains a transaction log but only updates its index via replication from a leader. See the section <<shards-and-indexing-data-in-solrcloud.adoc#types-of-replicas,Types of Replicas>> for more information about replica types.

`pullReplicas`::
The number of PULL replicas to create for this collection. This type of replica does not maintain a transaction log and only updates its index via replication from a leader. This type is not eligible to become a leader and should not be the only type of replicas in the collection. See the section <<shards-and-indexing-data-in-solrcloud.adoc#types-of-replicas,Types of Replicas>> for more information about replica types.

`maxShardsPerNode`::
When creating collections, the shards and/or replicas are spread across all available (i.e., live) nodes, and two replicas of the same shard will never be on the same node.
+
If a node is not live when the CREATE operation is called, it will not get any parts of the new collection, which could lead to too many replicas being created on a single live node. Defining `maxShardsPerNode` sets a limit on the number of replicas CREATE will spread to each node. If the entire collection can not be fit into the live nodes, no collection will be created at all.

`autoAddReplicas`::
When set to `true`, enables auto addition of replicas on shared file systems. See the section <<running-solr-on-hdfs.adoc#automatically-add-replicas-in-solrcloud,Automatically Add Replicas in SolrCloud>> for more details on settings and overrides.

`property._name_=_value_`::
Set core property _name_ to _value_. See the section <<defining-core-properties.adoc#defining-core-properties,Defining core.properties>> for details on supported properties and values.

== DELETENODE: Delete Replicas in a Node

Deletes all replicas of all collections in that node. Please note that the node itself will remain as a live node after this operation.

`/admin/collections?action=DELETENODE&node=nodeName`

=== DELETENODE Parameters

`node`::
The node to be removed. This parameter is required.

`async`::
Request ID to track this action which will be <<Asynchronous Calls,processed asynchronously>>.

== REPLACENODE: Move All Replicas in a Node to Another

This command recreates replicas in one node (the source) to another node(s) (the target). After each replica is copied, the replicas in the source node are deleted.

For source replicas that are also shard leaders the operation will wait for the number of seconds set with the `timeout` parameter to make sure there's an active replica that can become a leader (either an existing replica becoming a leader or the new replica completing recovery and becoming a leader).

The API uses the Autoscaling framework to find nodes that can satisfy the disk requirements for the new replicas but only when an Autoscaling policy is configured. Refer to <<solrcloud-autoscaling-policy-preferences.adoc#solrcloud-autoscaling-policy-preferences,Autoscaling Policy and Preferences>> section for more details.

`/admin/collections?action=REPLACENODE&sourceNode=_source-node_&targetNode=_target-node_`

=== REPLACENODE Parameters

`sourceNode`::
The source node from which the replicas need to be copied from. This parameter is required.

`targetNode`::
The target node where replicas will be copied. If this parameter is not provided, Solr will identify nodes automatically based on policies or number of cores in each node.

`parallel`::
If this flag is set to `true`, all replicas are created in separate threads. Keep in mind that this can lead to very high network and disk I/O if the replicas have very large indices. The default is `false`.

`async`::
Request ID to track this action which will be <<Asynchronous Calls,processed asynchronously>>.

`timeout`::
Time in seconds to wait until new replicas are created, and until leader replicas are fully recovered. The default is `300`, or 5 minutes.

[IMPORTANT]
====
This operation does not hold necessary locks on the replicas that belong to on the source node. So don't perform other collection operations in this period.
====

[[movereplica]]
== MOVEREPLICA: Move a Replica to a New Node

This command moves a replica from one node to a new node. In case of shared filesystems the `dataDir` will be reused.

The API uses the Autoscaling framework to find nodes that can satisfy the disk requirements for the replica to be moved but only when an Autoscaling policy is configured. Refer to <<solrcloud-autoscaling-policy-preferences.adoc#solrcloud-autoscaling-policy-preferences,Autoscaling Policy and Preferences>> section for more details.

`/admin/collections?action=MOVEREPLICA&collection=collection&shard=shard&replica=replica&sourceNode=nodeName&targetNode=nodeName`

=== MOVEREPLICA Parameters

`collection`::
The name of the collection. This parameter is required.

`shard`::
The name of the shard that the replica belongs to. This parameter is required.

`replica`::
The name of the replica. This parameter is required.

`sourceNode`::
The name of the node that contains the replica. This parameter is required.

`targetNode`::
The name of the destination node. This parameter is required.

`async`::
Request ID to track this action which will be <<Asynchronous Calls,processed asynchronously>>.

[[utilizenode]]
== UTILIZENODE: Utilize a New Node

This command can be used to move some replicas from the existing nodes to either a new node or a less loaded node to reduce the load on the existing node.

This uses your autoscaling policies and preferences to identify which replica needs to be moved. It tries to fix any policy violations first and then it tries to move some load off of the most loaded nodes according to the preferences.

`/admin/collections?action=UTILIZENODE&node=nodeName`

=== UTILIZENODE Parameters

`node`:: The name of the node that needs to be utilized. This parameter is required.


== Asynchronous Calls

Since some collection API calls can be long running tasks (such as SPLITSHARD), you can optionally have the calls run asynchronously. Specifying `async=<request-id>` enables you to make an asynchronous call, the status of which can be requested using the <<requeststatus,REQUESTSTATUS>> call at any time.

As of now, REQUESTSTATUS does not automatically clean up the tracking data structures, meaning the status of completed or failed tasks stays stored in ZooKeeper unless cleared manually. DELETESTATUS can be used to clear the stored statuses. However, there is a limit of 10,000 on the number of async call responses stored in a cluster.

=== Examples of Async Requests

*Input*

[source,text]
----
http://localhost:8983/solr/admin/collections?action=SPLITSHARD&collection=collection1&shard=shard1&async=1000&wt=xml
----

*Output*

[source,xml]
----
<response>
  <lst name="responseHeader">
    <int name="status">0</int>
    <int name="QTime">99</int>
  </lst>
  <str name="requestid">1000</str>
</response>
----
