Bug 1314108

Summary:	[RFE] Randomized scrub scheduling
Product:	Red Hat Ceph Storage	Reporter:	Neil Levine <nlevine>
Component:	RADOS	Assignee:	Kefu Chai <kchai>
Status:	CLOSED ERRATA	QA Contact:	shylesh <shmohan>
Severity:	medium	Docs Contact:	Bara Ancincova <bancinco>
Priority:	unspecified
Version:	1.3.2	CC:	ceph-eng-bugs, dzafman, gmeno, hnallurv, kchai, kdreyer, sjust, yweinste
Target Milestone:	rc
Target Release:	2.0
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:	ceph v10.2.0	Doc Type:	Enhancement
Doc Text:	.Support for randomized scrub scheduling has been added The new Ceph `osd_scrub_interval_randomize_ratio` configuration option randomizes scrub scheduling by adding a random delay to the value specified by the `osd_scrub_min_interval` option. As a result, scrubbing of newly created pool or placement groups does not happen at the same time, and I/O impact is reduced.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2016-08-23 19:32:14 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:
Bug Depends On:
Bug Blocks:	1322504

Description Neil Levine 2016-03-02 23:54:10 UTC

Overview

Scrubbing can be a resource intensive operation but is an important part of detecting bitrot in a cluster. Currently, we support (in Stockwell), the ability to schedule when scrubbing may happen (eg between 10pm and 2am). However
the period specified may not provide enough time to perform the scrub. The goal is to ensure that scrubbing is performed on ongoing basis but with intelligent scheduling.

Feature:

For newly created pools/PGs then scrubbing all happens at the same time.
Randomize scrub scheduling so IO impact is reduced. (Merged in Infernalis)

Comment 3 Christina Meno 2016-04-20 20:47:50 UTC

Is this merged in Jewel? I checked the release notes and the git log but couldn't figure it out.

Comment 4 David Zafman 2016-04-20 20:55:14 UTC

I see the configuration variable "osd_scrub_interval_randomize_ratio" in jewel.   So I'd say it is there.  The description above mentions that it was merged in Infernalis.

Comment 9 errata-xmlrpc 2016-08-23 19:32:14 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-2016:1755