Bug 1040460

Summary:	Even distribution policy selects the same host where there is no CPU load on the host
Product:	Red Hat Enterprise Virtualization Manager	Reporter:	Gilad Chaplik <gchaplik>
Component:	ovirt-engine	Assignee:	Gilad Chaplik <gchaplik>
Status:	CLOSED CURRENTRELEASE	QA Contact:	Artyom <alukiano>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	3.3.0	CC:	acathrow, dfediuck, iheim, lpeer, mavital, Rhev-m-bugs, scohen, yeylon
Target Milestone:	---
Target Release:	3.3.0
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:	sla
Fixed In Version:	is28	Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2014-01-21 22:12:39 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	SLA	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	1049022

Description Gilad Chaplik 2013-12-11 13:21:56 UTC

Description of problem:
When there is no CPU load on the host, the scheduler distribute the vm to the same non-SPM host.

How reproducible:
100%

Steps to Reproduce:
1. configure a cluster with 2 hosts, and select the even distribution policy.
2. start simultaneously several VMs on that cluster

Actual results:
All VMs starts on the same host (non-spm one).

Expected results:
VMs Should be evenly distributed on the hosts.

Additional info:
The problem caused since the even distribution weight function generates an integer as its score. The actual calculation is done on real numbers so if there is a different score, the function cover it up when rounding it.

Comment 3 Artyom 2013-12-19 15:24:24 UTC

verified on is28
Run simultaneously 16 vms
Result: 
host with SPM: 6 vms
host without SPM: 10 vms

Comment 4 Itamar Heim 2014-01-21 22:12:39 UTC

Closing - RHEV 3.3 Released