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[[default-logging-with-stderrlog]]
=== Default Logging with Jetty's StdErrLog

[[stderrlog-configuration]]
==== StdErrLog Configuration

If you do nothing to configure a separate logging framework, Jetty will default to using an internal `org.eclipse.jetty.util.log.StdErrLog` implementation.
This will output all logging events to STDERR (aka `System.err`).

Simply use Jetty and `StdErrLog`-based logging is output to the console.

Included in the Jetty distribution is a logging module named `console-capture` that is capable of performing simple capturing of all STDOUT (`System.out`) and STDERR (`System.err`) output to a file that is rotated daily.

To enable this feature, simply activate the `console-capture` module on the command line:

[source, screen, subs="{sub-order}"]
....
[my-base]$ java -jar ../start.jar --add-to-start=console-capture
INFO  : console-capture initialized in ${jetty.base}/start.d/console-capture.ini
MKDIR : ${jetty.base}/logs
INFO  : Base directory was modified

[my-base]$ tree
.
├── logs
└── start.d
    └── console-capture.ini
....

The default configuration for logging output will create a file `${jetty.base}/logs/yyyy_mm_dd.stderrout.log` which allows configuration of the output directory by setting the `jetty.logs` property.

____
[NOTE]
By default, logs are not set to be appended, meaning a the log file is wiped clean upon sever restart.
You can change this setting by editing the `console-capture.ini` and un-commenting the line that reads `jetty.console-capture.append=true`.
____


Just enabling the `console-capture` will simply output the values of STDERR and STDOUT to a log file.
To customize the log further, a module named `logging-jetty` is available to provides a default properties file to configure.
As with `console-capture`, you activate the `logging-jetty` on the command line.

[source, screen, subs="{sub-order}"]
....
[my-base]$ java -jar ../start.jar --add-to-start=logging-jetty
INFO  : logging-jetty   initialized in ${jetty.base}/start.d/logging-jetty.ini
INFO  : resources       transitively enabled
MKDIR : ${jetty.base}/resources
COPY  : ${jetty.home}/modules/logging-jetty/resources/jetty-logging.properties to ${jetty.base}/resources/jetty-logging.properties
INFO  : Base directory was modified

[my-base]$ tree
.
├── logs
├── resources
│   └── jetty-logging.properties
└── start.d
    ├── console-capture.ini
    └── logging-jetty.ini
....

Once activated, you can find the properties file at `${jetty.base}/resources/jetty-logging.properties`.
By default, the following parameters are defined.
To change them, un-comment the line and substitute your naming scheme and configuration choices.

[source, properties, subs="{sub-order}"]
....
## Force jetty logging implementation
#org.eclipse.jetty.util.log.class=org.eclipse.jetty.util.log.StdErrLog

## Set logging levels from: ALL, DEBUG, INFO, WARN, OFF
#org.eclipse.jetty.LEVEL=INFO
#com.example.LEVEL=INFO

## Hide stacks traces in logs?
#com.example.STACKS=false

## Show the source file of a log location?
#com.example.SOURCE=false
....

There are a number of properties that can be defined in the configuration that will affect the behavior of StdErr logging with `console-capture`.

`<name>.LEVEL=<level>`::
  Sets the logging level for all loggers within the `name` specified to the level, which can be (in increasing order of restriction) `ALL`, `DEBUG`, `INFO`, `WARN`, `OFF`.
  The name (or hierarchy) can be a specific fully qualified class or a package namespace.
  For example, `org.eclipse.jetty.http.LEVEL=DEBUG` is a package namespace approach to turn all loggers in the Jetty HTTP package to DEBUG level, and  `org.eclipse.jetty.io.ChanelEndPoint.LEVEL=ALL` turns on all logging events for the specific class, including `DEBUG`, `INFO`, `WARN` (and even special internally ignored exception classes).
  If more than one system property specifies a logging level, the most specific one applies.
`<name>.SOURCE=<boolean>`::
  Named Logger specific, attempts to print the Java source file name and line number from where the logging event originated.
  Name must be a fully qualified class name (this configurable does not support package name hierarchy).
  Default is false.
  Be aware that this is a slow operation and has an impact on performance.
`<name>.STACKS=<boolean>`::
  Named Logger specific, controls the display of stacktraces.
  Name must be a fully qualified class name (this configurable does not support package name hierarchy).
  Default is true.
`org.eclipse.jetty.util.log.stderr.SOURCE=<boolean>`::
  Special Global Configuration.
  Attempts to print the Java source file name and line number from where the logging event originated.
  Default is false.
`org.eclipse.jetty.util.log.stderr.LONG=<boolean>`::
  Special Global Configuration.
  When true, outputs logging events to `STDERR` using long form, fully qualified class names.
  When false, uses abbreviated package names.
  Default is false.
+
  * Example when set to false:
+
[source, screen, subs="{sub-order}"]
....
2016-10-21 15:31:01.248:INFO::main: Logging initialized @332ms to org.eclipse.jetty.util.log.StdErrLog
2016-10-21 15:31:01.370:INFO:oejs.Server:main: jetty-9.4.0-SNAPSHOT
2016-10-21 15:31:01.400:INFO:oejs.AbstractConnector:main: Started ServerConnector@2c330fbc{HTTP/1.1,[http/1.1]}{0.0.0.0:8080}
2016-10-21 15:31:01.400:INFO:oejs.Server:main: Started @485ms
....
+
  * Example when set to true:
+
[source, screen, subs="{sub-order}"]
....
2016-10-21 15:31:35.020:INFO::main: Logging initialized @340ms to org.eclipse.jetty.util.log.StdErrLog
2016-10-21 15:31:35.144:INFO:org.eclipse.jetty.server.Server:main: jetty-9.4.0-SNAPSHOT
2016-10-21 15:31:35.174:INFO:org.eclipse.jetty.server.AbstractConnector:main: Started ServerConnector@edf4efb{HTTP/1.1,[http/1.1]}{0.0.0.0:8080}
2016-10-21 15:31:35.175:INFO:org.eclipse.jetty.server.Server:main: Started @495ms
....

[[deprecated-parameters]]
==== Deprecated Parameters

These parameters existed in prior versions of Jetty, and are no longer supported.
They are included here for historical (and search engine) reasons.

`org.eclipse.jetty.util.log.DEBUG`::
  Formerly used to enable DEBUG level logging on any logger used within Jetty (not just Jetty's own logger).
  * Replaced with using the logger implementation specific configuration and level filtering.
`org.eclipse.jetty.util.log.stderr.DEBUG`::
  Formerly used to enable DEBUG level logging on the internal Jetty `StdErrLog` implementation.
  * Replaced with level specific equivalent.
    Example: `org.eclipse.jetty.LEVEL=DEBUG`
`DEBUG`::
  Ancient debugging flag that turned on all debugging, even non-logging debugging.
  * Jetty no longer uses because many third party libraries employ this overly simple property name, which would generate far too much console output.
