Bug 1112720

Summary:	Possible db deadlock between VdsUpdateRuntimeInfo and multiple images operations
Product:	[Retired] oVirt	Reporter:	Liron Aravot <laravot>
Component:	ovirt-engine-core	Assignee:	Liron Aravot <laravot>
Status:	CLOSED CURRENTRELEASE	QA Contact:	Gal Amado <gamado>
Severity:	urgent	Docs Contact:
Priority:	unspecified
Version:	3.5	CC:	amureini, gklein, iheim, obasan, rbalakri, scohen, yeylon
Target Milestone:	---
Target Release:	3.5.0
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:	storage
Fixed In Version:	ovirt-engine-3.5.0_beta	Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2014-10-17 12:34:42 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	Storage	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Liron Aravot 2014-06-24 14:43:52 UTC

Description of problem:
Currently VdsUpdateRuntimeInfo updates the disc_image_dynamic table
according to the statistics retreived from the running vms.
Those updates are executed in a batchUpdate call, which currently
executes all the updates within the same transaction, as there is a FK
between the disk_image_dynamic on postgres version earlier than 9.3 a
lock will be taken on the referenced row which means that any other
concurrent operation on those images may cause to a deadlock.


Steps to Reproduce:
1. Run VM with multiple disks
2. Attempt to live migrate the vm disks on the same time

Actual results:
db deadlock might occur

Expected results:
db deadlock shouldn't occur

Comment 1 Gal Amado 2014-08-12 08:44:37 UTC

Verified on :
oVirt Engine Version: 3.5.0-0.0.master.20140804172041.git23b558e.el6
vdsm : vdsm-4.16.1-6.gita4a4614.el6.x86_64 

Creates VM with 4 disks.
Using the GUI , I Moved all 4 at once from One SD to the other (both are ISCSI).
Did that 3 times .

No Error at engine.log

Comment 2 Sandro Bonazzola 2014-10-17 12:34:42 UTC

oVirt 3.5 has been released and should include the fix for this issue.