Bug 1201485

Summary: Node selection logic does not properly distribute gear load
Product: OpenShift Container Platform Reporter: Timothy Williams <tiwillia>
Component: NodeAssignee: Luke Meyer <lmeyer>
Status: CLOSED ERRATA QA Contact: libra bugs <libra-bugs>
Severity: high Docs Contact:
Priority: high    
Version: 2.2.0CC: adellape, bleanhar, jialiu, jokerman, libra-onpremise-devel, mmccomas, pruan, xiama
Target Milestone: ---Keywords: Upstream
Target Release: ---   
Hardware: x86_64   
OS: Linux   
Whiteboard:
Fixed In Version: rubygem-openshift-origin-msg-broker-mcollective-1.33.1.1-1 Doc Type: Bug Fix
Doc Text:
The default gear placement algorithm did not properly distribute gear load in some district configurations. Some nodes would be ignored until other nodes filled up. This bug fix updates this logic, and gear load is now better distributed.
 Story Points: ---
Clone Of: Environment:
Last Closed: 2015-04-06 17:06:36 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:

Description Timothy Williams 2015-03-12 19:17:00 UTC 
Description of problem:
The default node selection logic does not properly distribute gear load. In a 13-node district, 2-3 nodes will remain ignored until other nodes fill up under the current logic.

Version-Release number of selected component (if applicable):
2.2

How reproducible:
Always

Steps to Reproduce:
1. Create an environment with at least 13 nodes (have not tested with <13, but may reproduce with less). Each node should be the same gear size.
2. Create a district and add all 13 nodes.
2. Create 100 applications.
3. Check gear distribution with `oo-admin-ctl-gears | wc -l` on each node

Actual results:
Several nodes will be ignored, with no applications created on them:

Gear counts:
  Node1: 8
  Node2: 9
  Node3: 9
  Node4: 9
  Node5: 9
  Node6: 9
  Node7: 9
  Node8: 8
  Node9: 0
  Node10: 0
  Node11: 10
  Node12: 8
  Node13: 12

Expected results:
All nodes have even (or close to even) gear counts:

  Node1: 8
  Node2: 8
  Node3: 8
  Node4: 8
  Node5: 8
  Node6: 8
  Node7: 8
  Node8: 8
  Node9: 7
  Node10: 7
  Node11: 7
  Node12: 7
  Node13: 8
Comment 19 errata-xmlrpc 2015-04-06 17:06:36 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://rhn.redhat.com/errata/RHBA-2015-0779.html