Bug 1262460 - Backport mon: add a cache layer over MonitorDBStore #5524
Backport mon: add a cache layer over MonitorDBStore #5524
Product: Red Hat Ceph Storage
Classification: Red Hat
Component: RADOS (Show other bugs)
x86_64 Linux
unspecified Severity high
: rc
: 1.2.4
Assigned To: Kefu Chai
: 1262492 (view as bug list)
Depends On:
Blocks: 1319075 1228319
  Show dependency treegraph
Reported: 2015-09-11 15:08 EDT by Kyle Squizzato
Modified: 2017-07-30 11:21 EDT (History)
6 users (show)

See Also:
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:
: 1262985 (view as bug list)
Last Closed: 2015-10-01 16:25:53 EDT
Type: Bug
Regression: ---
Mount Type: ---
Documentation: ---
Verified Versions:
Category: ---
oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---

Attachments (Terms of Use)

External Trackers
Tracker ID Priority Status Summary Last Updated
Ceph Project Bug Tracker 12638 None None None Never
Red Hat Knowledge Base (Solution) 1590683 None None None 2017-07-30 11:08 EDT

  None (edit)
Description Kyle Squizzato 2015-09-11 15:08:32 EDT
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 17:53:34 EDT
Fix will be in non-RHEL Ceph v0.80.8.5
Comment 7 Tamil 2015-09-17 17:38:25 EDT
Kefu, can you please tell us the steps to verify the bug fix.
Comment 8 Kefu Chai 2015-09-17 22:33:39 EDT
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 16:25:53 EDT
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.

Comment 15 Ken Dreyer (Red Hat) 2015-10-21 12:07:47 EDT
*** Bug 1262492 has been marked as a duplicate of this bug. ***

Note You need to log in before you can comment on or make changes to this bug.