Bug 1505561 - [RHCS 2.y] OSD heartbeat timeout due to too many omap entries read in each 'chunk' being backfilled
Summary: [RHCS 2.y] OSD heartbeat timeout due to too many omap entries read in each 'c...
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Red Hat Ceph Storage
Classification: Red Hat Storage
Component: RADOS
Version: 2.4
Hardware: x86_64
OS: Linux
high
medium
Target Milestone: rc
: 2.5
Assignee: Josh Durgin
QA Contact: Manohar Murthy
Aron Gunn
URL:
Whiteboard:
Depends On: 1505559
Blocks: 1536401
TreeView+ depends on / blocked
 
Reported: 2017-10-23 21:13 UTC by Vikhyat Umrao
Modified: 2021-06-10 13:20 UTC (History)
9 users (show)

Fixed In Version: RHEL: ceph-10.2.10-11.el7cp Ubuntu: ceph_10.2.10-8redhat1xenial
Doc Type: Bug Fix
Doc Text:
.The OSD no longer times out when backfilling Previously, backfilling objects with hundreds of thousands of `omap` entries could cause the OSD to time out. With this release, the backfilling process now reads a maximum of 8096 `omap` entries at a time, allowing the OSDs to continue running.
Clone Of:
Environment:
Last Closed: 2018-02-21 19:44:55 UTC
Embargoed:


Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Ceph Project Bug Tracker 21897 0 None None None 2017-10-23 21:23:06 UTC
Red Hat Bugzilla 1505559 0 high CLOSED [RHCS 3] OSD heartbeat timeout due to too many omap entries read in each 'chunk' being backfilled 2021-06-10 13:20:02 UTC
Red Hat Knowledge Base (Solution) 3222691 0 None None None 2017-10-23 21:36:54 UTC
Red Hat Product Errata RHBA-2018:0340 0 normal SHIPPED_LIVE Red Hat Ceph Storage 2.5 bug fix and enhancement update 2018-02-22 00:50:32 UTC

Internal Links: 1505559

Description Vikhyat Umrao 2017-10-23 21:13:58 UTC
Description of problem:
[RHCS 2.y] OSD heartbeat timeout due to too many omap entries read in each 'chunk' being backfilled


Version-Release number of selected component (if applicable):
Red Hat Ceph Storage 2.4 

How reproducible:
Always in the scale lab


Additional info:

Testing in the scale lab uncovered an area where osds were
hitting heartbeat timeouts during backfill.

This turned out to be due to too many omap entries read in each 'chunk'
being backfilled, and only resetting the heartbeat once an entire chunk was assembled. We should ask Athena to tune this down for their
bucket index osds - setting:

Max number of omap entries per chunk:

    osd_recovery_max_omap_entries_per_chunk = 1024

Josh is planning to add a patch for 3.0 and 2.5 to reset the heartbeat in middle of gathering a chunk, which should make the current default of 64000
entries per backfill chunk work even with large stores.

Comment 16 errata-xmlrpc 2018-02-21 19:44:55 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-2018:0340


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