Bug 1262460

Summary:	Backport mon: add a cache layer over MonitorDBStore #5524
Product:	[Red Hat Storage] Red Hat Ceph Storage	Reporter:	Kyle Squizzato <ksquizza>
Component:	RADOS	Assignee:	Kefu Chai <kchai>
Status:	CLOSED ERRATA	QA Contact:	ceph-qe-bugs <ceph-qe-bugs>
Severity:	high	Docs Contact:
Priority:	unspecified
Version:	1.2.3	CC:	ceph-eng-bugs, dzafman, kchai, kdreyer, nlevine, tmuthami
Target Milestone:	rc
Target Release:	1.2.4
Hardware:	x86_64
OS:	Linux
Whiteboard:
Fixed In Version:	ceph-0.80.8-17 (RHEL) and ceph v0.80.8.5 (Ubuntu & CentOS 6)	Doc Type:	Bug Fix
Doc Text:	Prior to this update, poor LevelDB performance in Ceph's monitors could cause spurious elections. This could lead to slow requests during re-balancing. With this update, Ceph now caches the osdmap to be sent to the monitor clients, and cluster performance is improved.	Story Points:	---
Clone Of:
Clones:	1262985 (view as bug list)		Environment:
Last Closed:	2015-10-01 20:25:53 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:	1228319, 1319075

Description Kyle Squizzato 2015-09-11 19:08:32 UTC

Help to prevent spurious election behavior caused by poor leveldb performance which leads to slow OSD restarts.

Upstream tracker: http://tracker.ceph.com/issues/12638 
Upstream PR: https://github.com/ceph/ceph/pull/5524

Comment 6 Ken Dreyer (Red Hat) 2015-09-15 21:53:34 UTC

Fix will be in non-RHEL Ceph v0.80.8.5

Comment 7 Tamil 2015-09-17 21:38:25 UTC

Kefu, can you please tell us the steps to verify the bug fix.

Comment 8 Kefu Chai 2015-09-18 02:33:39 UTC

Tamil, i am not sure if we have a way to verify the cache for the monstore. the cache layer speeds up the access to the leveldb. we don't leave traces/print extra message when we are accessing the leveldb directly without the cache, and no extra message is printed when we are using the cache.

Comment 14 errata-xmlrpc 2015-10-01 20:25:53 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://access.redhat.com/errata/RHBA-2015:1857

Comment 15 Ken Dreyer (Red Hat) 2015-10-21 16:07:47 UTC

*** Bug 1262492 has been marked as a duplicate of this bug. ***