Bug 1203025

Summary: Perf: Throughput falls to 0 and CPU spikes during smallfile tests.
Product: [Red Hat Storage] Red Hat Gluster Storage Reporter: Ben Turner <bturner>
Component: coreAssignee: Bug Updates Notification Mailing List <rhs-bugs>
Status: CLOSED WORKSFORME QA Contact: Ben Turner <bturner>
Severity: high Docs Contact:
Priority: high    
Version: rhgs-3.0CC: asriram, asrivast, atumball, bturner, nbalacha, rcyriac, rgowdapp, rhs-bugs, sankarshan, smohan, spalai, srangana
Target Milestone: ---Keywords: ZStream
Target Release: ---   
Hardware: x86_64   
OS: Linux   
Whiteboard: dht-smallfile-perf, dht-pm-query
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2018-01-29 17:38:58 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:    
Bug Blocks: 1202842    

Description Ben Turner 2015-03-17 23:16:57 UTC 
Description of problem:

During smallfile tests glusterfs throughput to the local brick falls to 0 and CPU spikes.  Gluster appears to be choking on something when the CPU spikes and throughput drops to 0.

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

glusterfs 3.6.0.52

How reproducible:

Everytime.

Steps to Reproduce:
1.  Run a smallfile test.
2.  Watch iostat
3.  See MB / sec drop and CPU spike

Actual results:

Drops in throughput and CPU spikes.

Expected results:

More sustained throughput to the bricks as the long periods of little to no throughput really hurts MB / sec.

Additional info:
Comment 11 Amar Tumballi 2018-01-29 17:38:58 UTC 
Have not seen the issue in last 2+ years of perf testing. Please feel free to reopen if seen again with latest versions.