Bug 1502610 - disperse eager-lock degrades performance for file create workloads
Summary: disperse eager-lock degrades performance for file create workloads
Keywords:
Status: CLOSED CURRENTRELEASE
Alias: None
Product: GlusterFS
Classification: Community
Component: disperse
Version: mainline
Hardware: x86_64
OS: Linux
unspecified
high
Target Milestone: ---
Assignee: Xavi Hernandez
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks: 1502455 1512460 1530519
TreeView+ depends on / blocked
 
Reported: 2017-10-16 10:40 UTC by Xavi Hernandez
Modified: 2018-03-15 11:18 UTC (History)
4 users (show)

Fixed In Version: glusterfs-4.0.0
Doc Type: If docs needed, set a value
Doc Text:
Clone Of: 1502455
: 1512460 1530519 (view as bug list)
Environment:
Last Closed: 2018-03-15 11:18:57 UTC
Regression: ---
Mount Type: ---
Documentation: ---
CRM:
Verified Versions:
Embargoed:


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Description Xavi Hernandez 2017-10-16 10:40:30 UTC
+++ This bug was initially created as a clone of Bug #1502455 +++

Description of problem:
The current behavior of the option disperse.eager-lock is not optimal:

disperse.eager-lock on: good performance on large-file read/write, but actually degrades performance for many file create workloads. The degradation for file create workloads seems to be due to lock contention on directories.

disperse.eager-lock off: loses the performance advantages of eager-locking for large-file access, but better performance on file create workloads than with disperse.eager-lock on.

We should fix eager locking so that it can be kept on without incurring a performance penalty on file create workloads.

Version-Release number of selected component (if applicable):
glusterfs*-3.12.1-2.el7.x86_64

How reproducible:
Consistently

--- Additional comment from Manoj Pillai on 2017-10-16 07:32:52 CEST ---


IMO, a solution that adds a separate option to control eager locking in the case of directories would be acceptable, and probably simple. 

So the default could be:
disperse.dir-eager-lock off: applies to directories
disperse.eager-lock on: applies to regular files

Would that work?

--- Additional comment from Xavier Hernandez on 2017-10-16 10:12:26 CEST ---

I guess this problem happens when multiple clients are creating files on the same directory, right ? otherwise, eager-locking shouldn't interfere with file creation (in fact it should be faster).

In cases where multiple clients access the same directory, then yes, we could keep a separate configuration for this purpose. However, is it really necessary to have it disabled by default ? I think that an scenario where multiple clients are writing to the same directory is less probable than one where all writes to a single directory come from the same client.

Comment 1 Worker Ant 2017-10-16 12:00:22 UTC
REVIEW: https://review.gluster.org/18530 (cluster/ec: create eager-lock option for non-regular files) posted (#1) for review on master by Xavier Hernandez (jahernan)

Comment 2 Worker Ant 2017-10-16 17:31:01 UTC
REVIEW: https://review.gluster.org/18530 (cluster/ec: create eager-lock option for non-regular files) posted (#2) for review on master by Xavier Hernandez (jahernan)

Comment 3 Worker Ant 2017-11-05 03:42:21 UTC
COMMIT: https://review.gluster.org/18530 committed in master by  

------------- cluster/ec: create eager-lock option for non-regular files

A new option is added to allow independent configuration of eager
locking for regular files and non-regular files.

Change-Id: I8f80e46d36d8551011132b15c0fac549b7fb1c60
BUG: 1502610
Signed-off-by: Xavier Hernandez <jahernan>

Comment 4 Worker Ant 2017-11-14 09:56:20 UTC
REVIEW: https://review.gluster.org/18763 (cluster/ec: Fix op-version for disperse.other-eager-lock) posted (#1) for review on master by Xavier Hernandez

Comment 5 Worker Ant 2017-11-14 17:31:44 UTC
COMMIT: https://review.gluster.org/18763 committed in master by \"Xavier Hernandez\" <jahernan> with a commit message- cluster/ec: Fix op-version for disperse.other-eager-lock

The op-version used for the new option was wrong. It has been set
to 3.13.0.

Change-Id: I88fbd7834e4a8018c8906303e734c251e90be8cf
BUG: 1502610
Signed-off-by: Xavier Hernandez <jahernan>

Comment 6 Shyamsundar 2018-03-15 11:18:57 UTC
This bug is getting closed because a release has been made available that should address the reported issue. In case the problem is still not fixed with glusterfs-4.0.0, please open a new bug report.

glusterfs-4.0.0 has been announced on the Gluster mailinglists [1], packages for several distributions should become available in the near future. Keep an eye on the Gluster Users mailinglist [2] and the update infrastructure for your distribution.

[1] http://lists.gluster.org/pipermail/announce/2018-March/000092.html
[2] https://www.gluster.org/pipermail/gluster-users/


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