Bug 971610

Summary:	Scaled app head gear hits nofile ulimits...
Product:	OpenShift Online	Reporter:	Thomas Wiest <twiest>
Component:	Containers	Assignee:	Rob Millner <rmillner>
Status:	CLOSED CURRENTRELEASE	QA Contact:	libra bugs <libra-bugs>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	2.x	CC:	bmeng, chunchen, mfisher, rmillner
Target Milestone:	---
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:
Clones:	1047437 (view as bug list)		Environment:
Last Closed:	2013-06-24 14:52:09 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:	1047437

Description Thomas Wiest 2013-06-06 22:51:00 UTC

Description of problem:
We found while trying to scale the summit presentation that the head haproxy gear is hitting the nofile ulimit (which is set to 4096 by default). 

We added these lines to this file /etc/security/limits.d/84-51ae792fe0b8cdddf2000177.conf:
51ae792fe0b8cdddf2000177               soft    nofile          16384
51ae792fe0b8cdddf2000177               hard    nofile          16384

And that helped out tremendously.


Version-Release number of selected component (if applicable):
rhc-node-1.9.15-1.el6oso.x86_64


How reproducible:
very


Steps to Reproduce:
1. create a scaled app with at least 4 backed gears (5 gears total)
2. pound on the app
3. watch netstat -nap on the head gear's node and notice that the connections are being limited to the head gear.
4. bump the limit
5. notice that the head gear can scale better


Actual results:
Slow head gear because of file descriptors are being limited. This makes the backend gears not be able to contribute enough.


Expected results:
fast connections

Comment 1 Rob Millner 2013-06-12 18:26:02 UTC

Only the hard limit needs to be increased.  Haproxy will request an increase up to the hard limit based on the number of connections its configured for.

Release ticket updated.

Pull request for devenv:
https://github.com/openshift/li/pull/1618



To Q/A:
1. create a scaled app.
2. log into your gear and edit haproxy/conf/haproxy.cfg
3. change the value of "maxconn" to 8000
4. restart your app
5. log back into the gear and inspect haproxy/logs/haproxy.log

Expected:
No errors like "FD limit (1024) too low for maxconn=8000..."

Comment 2 openshift-github-bot 2013-06-12 21:35:44 UTC

Commit pushed to master at https://github.com/openshift/li

https://github.com/openshift/li/commit/d4b70a6a4a31fd33ac0d25a76d9d42630bd16bf3
Bug 971610 - Increase the hard limit on file descriptors to 16k

Comment 3 Meng Bo 2013-06-14 06:50:53 UTC

Checked on devenv_3360,

Step as comment#1,

After restart app, no such errors in haproxy.log

Move bug to verified.