Bug 1337018 – [RFE] filestore: randomize split threshold

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Bug 1337018 - [RFE] filestore: randomize split threshold

Summary:	[RFE] filestore: randomize split threshold

Status:	CLOSED ERRATA

Aliases:	None

Product:	Red Hat Ceph Storage
Classification:	Red Hat
Component:	RADOS (Show other bugs)
Sub Component:
Version:	1.3.2
Hardware:	x86_64 Linux

Priority	urgent Severity urgent
Target Milestone:	rc
Target Release:	3.0
Assigned To:	Josh Durgin
QA Contact:	shylesh
Docs Contact:

URL:
Whiteboard:
Keywords:	FutureFeature

Duplicates:	1219974 (view as bug list)
Depends On:
Blocks:	1258382 1494421
	Show dependency tree / graph

Reported:	2016-05-18 00:48 EDT by Vikhyat Umrao
Modified:	2018-02-26 09:44 EST (History)
CC List:	9 users (show)

See Also:	1219974 1332874
Fixed In Version:	RHEL: ceph-12.1.2-1.el7cp Ubuntu: ceph_12.1.2-2redhat1xenial
Doc Type:	Bug Fix
Doc Text:	.Split threshold is now randomized Previously, the split threshold was not randomized, so that many OSDs reached it at the same time. As a consequence, such OSDs incurred high latency because they all split directories at once. With this update, the split threshold is randomized which ensures that OSDs split directories over a large period of time.
Story Points:	---
Clone Of:
Clones:	1533266 (view as bug list)
Environment:
Last Closed:	2017-12-05 18:29:38 EST
Type:	Bug
Regression:	---
Mount Type:	---
Documentation:	---
CRM:
Verified Versions:
Category:	---
oVirt Team:	---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---

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External Trackers
Tracker	ID	Priority	Status	Summary	Last Updated
Red Hat Knowledge Base (Solution)	3364191	None	None	None	2018-02-26 09:44 EST
Ceph Project Bug Tracker	15835	None	None	None	2016-05-18 00:51 EDT
Red Hat Product Errata	RHBA-2017:3387	normal	SHIPPED_LIVE	Red Hat Ceph Storage 3.0 bug fix and enhancement update	2017-12-05 22:03:45 EST

Groups: None (edit)

Description Vikhyat Umrao 2016-05-18 00:48:41 EDT

Description of problem:
[RFE] filestore: randomize split threshold

- If the distribution of files is roughly even, many osds will reach the split threshold at the same time, causing them all to incur high latency as they all split directories at once.

- A simple change that may mitigate this is to randomize the split threshold, similar to the randomized scrub threshold, so different osds split directories over a larger period of time.

For more information Please Check Bugzilla : https://bugzilla.redhat.com/show_bug.cgi?id=1291632 and specific comment#55 : https://bugzilla.redhat.com/show_bug.cgi?id=1332874#c55



Version-Release number of selected component (if applicable):
Red Hat Ceph Storage 1.3.2
Upstream Hammer

Comment 3 Vikhyat Umrao 2016-05-18 00:51:52 EDT

BZ link mistake in comment#0 : 

s/https://bugzilla.redhat.com/show_bug.cgi?id=1291632/https://bugzilla.redhat.com/show_bug.cgi?id=1332874

Upstream Feature tracker : http://tracker.ceph.com/issues/15835

Comment 9 Josh Durgin 2017-05-18 17:01:37 EDT

*** Bug 1219974 has been marked as a duplicate of this bug. ***

Comment 10 Ian Colle 2017-07-31 23:49:38 EDT

https://github.com/ceph/ceph/pull/15689 Merged

Comment 17 errata-xmlrpc 2017-12-05 18:29:38 EST

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-2017:3387

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