Bug 1501013

Summary: [fuse-bridge] - Make event-history option configurable and have it disabled by default.
Product: [Red Hat Storage] Red Hat Gluster Storage Reporter: Krutika Dhananjay <kdhananj>
Component: fuseAssignee: Krutika Dhananjay <kdhananj>
Status: CLOSED ERRATA QA Contact: Sweta Anandpara <sanandpa>
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: rhgs-3.3CC: kdhananj, rhs-bugs, sanandpa, sheggodu, srmukher, storage-qa-internal
Target Milestone: ---   
Target Release: RHGS 3.4.0   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: rebase
Fixed In Version: glusterfs-3.12.2-1 Doc Type: Bug Fix
Doc Text:
Previously fuse event-history was enabled by default and there was no way to disable it. With this fix, you can make fuse event-history optional and disable it by default, since it is required only when a trace of fops from fuse's point of view is required for debugging any issues/errors.
 Story Points: ---
Clone Of: Environment:
Last Closed: 2018-09-04 06:36:52 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On: 1467614    
Bug Blocks: 1503134    
Attachments:
Description Flags
RHGS 3.4 verification logs none

Description Krutika Dhananjay 2017-10-12 02:51:23 UTC 
Description of problem:

This is because having it disabled seems to improve performance. This is due to the lock contention by the different epoll threads as well as the fuse thread on the circular buff lock both in the fop call and callback paths.

Just to provide some data - wrt RHHI, I saw an increase in IOPs by 12K with event-history disabled for randrom read workload on Sanjay's setup. So the iops I used to get previously was around 61K. With event-history disabled, iops went up to ~73K.

Moreover this codepath is not unique to RHHI. It should help the other use cases too.

Usage:
mount -t glusterfs -o event-history=on $HOSTNAME:$VOLNAME $MOUNTPOINT
OR
glusterfs --event-history=on --volfile-server=$HOSTNAME --volfile-id=$VOLNAME $MOUNTPOINT

Version-Release number of selected component (if applicable):


How reproducible:


Steps to Reproduce:
1.
2.
3.

Actual results:


Expected results:


Additional info:
Comment 2 Krutika Dhananjay 2017-10-12 02:53:23 UTC 
The patch and its backports are merged upstream.

https://review.gluster.org/#/c/18242/
https://review.gluster.org/#/c/18387/
https://review.gluster.org/#/c/18395/
Comment 7 Sweta Anandpara 2018-04-23 04:32:36 UTC 
Created attachment 1425497 [details]
RHGS 3.4 verification logs
Comment 10 errata-xmlrpc 2018-09-04 06:36:52 UTC 
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHSA-2018:2607