[Bugs] [Bug 1406547] New: Poor write performance with sharding enabled

[bugzilla at redhat.com]

https://bugzilla.redhat.com/show_bug.cgi?id=1406547

            Bug ID: 1406547
           Summary: Poor write performance with sharding enabled
           Product: GlusterFS
           Version: 3.8
         Component: sharding
          Assignee: bugs at gluster.org
          Reporter: dgallowa at redhat.com
        QA Contact: bugs at gluster.org
                CC: bugs at gluster.org



Created attachment 1234084
  --> https://bugzilla.redhat.com/attachment.cgi?id=1234084&action=edit
replica 2 and replica 3 arbiter 1 tests before and after sharding

Description of problem:
Enabling sharding on gluster volumes seems to at least halve write performance.

Version-Release number of selected component (if applicable):
3.8.6

How reproducible:
Very

Steps to Reproduce:
1. Create replica 2 (or replica 3 arbiter 1) volume
2. Fuse mount the volume and perform some write tests
3. Enable sharding

Actual results:
Observe slower write performance.

Expected results:
No or minimal decrease in write performance?

Additional info:
See attachment for write speed tests as requested by Ravi on internal mailing
list.

Bear in mind the hosts used for this test are actively used as backend VM
storage for my RHEV cluster so the results vary a bit.  What is clear whether
using replica 2 or arbiter is that sharding dramatically reduces write speeds.

For reference, I am able to achieve write speeds of around 300MB/s when writing
directly to disk (no Gluster involved).

-- 
You are receiving this mail because:
You are the QA Contact for the bug.
You are on the CC list for the bug.
You are the assignee for the bug.