From 8fb1fb71943aa602ac52a271563b141aa764ea69 Mon Sep 17 00:00:00 2001
From: Ashish Pandey <aspandey@redhat.com>
Date: Thu, 14 Apr 2016 16:19:40 +0530
Subject: [PATCH 389/393] cluster/ec: Add/Modify description for eager-lock
option
This patch provides description for disperse.eager-lock
option for disperse volume.
It also modifies the description for cluster.eager-lock
option to indicate that this option is only for replica
volume.
>Change-Id: Ie73298947fcaaa6aaf825978bc2d27ceaff386d2
>BUG: 1327171
>Signed-off-by: Ashish Pandey <aspandey@redhat.com>
>Reviewed-on: http://review.gluster.org/13999
>NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
>Smoke: Gluster Build System <jenkins@build.gluster.com>
>Reviewed-by: Ravishankar N <ravishankar@redhat.com>
>CentOS-regression: Gluster Build System <jenkins@build.gluster.com>
>Reviewed-by: Pranith Kumar Karampuri <pkarampu@redhat.com>
BUG: 1435656
Change-Id: Ie73298947fcaaa6aaf825978bc2d27ceaff386d2
Signed-off-by: Sunil Kumar Acharya <sheggodu@redhat.com>
Reviewed-on: https://code.engineering.redhat.com/gerrit/101383
Reviewed-by: Atin Mukherjee <amukherj@redhat.com>
---
xlators/cluster/afr/src/afr.c | 9 +++++----
xlators/cluster/ec/src/ec.c | 14 ++++++++++++--
2 files changed, 17 insertions(+), 6 deletions(-)
diff --git a/xlators/cluster/afr/src/afr.c b/xlators/cluster/afr/src/afr.c
index b76a06a..375bd1f 100644
--- a/xlators/cluster/afr/src/afr.c
+++ b/xlators/cluster/afr/src/afr.c
@@ -779,16 +779,17 @@ struct volume_options options[] = {
{ .key = {"eager-lock"},
.type = GF_OPTION_TYPE_BOOL,
.default_value = "on",
- .description = "Lock phase of a transaction has two sub-phases. "
+ .description = "Enable/Disable eager lock for replica volume. "
+ "Lock phase of a transaction has two sub-phases. "
"First is an attempt to acquire locks in parallel by "
"broadcasting non-blocking lock requests. If lock "
"acquisition fails on any server, then the held locks "
- "are unlocked and revert to a blocking locked mode "
+ "are unlocked and we revert to a blocking locks mode "
"sequentially on one server after another. If this "
"option is enabled the initial broadcasting lock "
- "request attempt to acquire lock on the entire file. "
+ "request attempts to acquire a full lock on the entire file. "
"If this fails, we revert back to the sequential "
- "\"regional\" blocking lock as before. In the case "
+ "\"regional\" blocking locks as before. In the case "
"where such an \"eager\" lock is granted in the "
"non-blocking phase, it gives rise to an opportunity "
"for optimization. i.e, if the next write transaction "
diff --git a/xlators/cluster/ec/src/ec.c b/xlators/cluster/ec/src/ec.c
index 5c85677..dfd8129 100644
--- a/xlators/cluster/ec/src/ec.c
+++ b/xlators/cluster/ec/src/ec.c
@@ -1363,8 +1363,18 @@ struct volume_options options[] =
{ .key = {"eager-lock"},
.type = GF_OPTION_TYPE_BOOL,
.default_value = "on",
- .description = "This option will enable/diable eager lock for"
- "disperse volume "
+ .description = "Enable/Disable eager lock for disperse volume. "
+ "If a fop takes a lock and completes its operation, "
+ "it waits for next 1 second before releasing the lock, "
+ "to see if the lock can be reused for next fop from "
+ "the same client. If ec finds any lock contention within "
+ "1 second it releases the lock immediately before time "
+ "expires. This improves the performance of file operations."
+ "However, as it takes lock on first brick, for few operations "
+ "like read, discovery of lock contention might take long time "
+ "and can actually degrade the performance. "
+ "If eager lock is disabled, lock will be released as soon as fop "
+ "completes. "
},
{ .key = {"background-heals"},
.type = GF_OPTION_TYPE_INT,
--
1.8.3.1