Bug 1262415

Summary:	Data Tiering:Scanning files in cold tier when detach tier is issued can take a toll on performance
Product:	[Community] GlusterFS	Reporter:	Nag Pavan Chilakam <nchilaka>
Component:	tiering	Assignee:	Dan Lambright <dlambrig>
Status:	CLOSED EOL	QA Contact:	bugs <bugs>
Severity:	high	Docs Contact:
Priority:	medium
Version:	3.7.4	CC:	bugs, dlambrig, sankarshan
Target Milestone:	---	Keywords:	Triaged
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:
Clones:	1278350 (view as bug list)		Environment:
Last Closed:	2017-03-08 10:53:43 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:	1278350

Description Nag Pavan Chilakam 2015-09-11 15:12:24 UTC

Description of problem:
=======================
I had about 1Lakh files in cold tier and no files in hot tier.
I then issued a detach tier start and check the status.
the status after complete showed as files scanned as all 1Lakh,
Which means if it is rightly showing, we are unncessarily scanning cold tier, which we must avoid for performance sake.

In below case it can be seen that it took about nearly two minutes for detach tier to complete, as it had scanned all cold files. In this case it should have got over in a few seconds as there were no hot files in hot tier.




Version-Release number of selected component (if applicable):
================================================================
[root@zod ~]# rpm -qa|grep gluster
glusterfs-client-xlators-3.7.4-0.27.git143f0f9.el7.centos.x86_64
glusterfs-cli-3.7.4-0.27.git143f0f9.el7.centos.x86_64
glusterfs-libs-3.7.4-0.27.git143f0f9.el7.centos.x86_64
glusterfs-api-3.7.4-0.27.git143f0f9.el7.centos.x86_64
glusterfs-fuse-3.7.4-0.27.git143f0f9.el7.centos.x86_64
glusterfs-debuginfo-3.7.4-0.27.git143f0f9.el7.centos.x86_64
glusterfs-server-3.7.4-0.27.git143f0f9.el7.centos.x86_64
glusterfs-3.7.4-0.27.git143f0f9.el7.centos.x86_64
[root@zod ~]# gluster --version
glusterfs 3.7.4 built on Sep  9 2015 01:30:47
Repository revision: git://git.gluster.com/glusterfs.git
Copyright (c) 2006-2011 Gluster Inc. <http://www.gluster.com>
GlusterFS comes with ABSOLUTELY NO WARRANTY.
You may redistribute copies of GlusterFS under the terms of the GNU General Public License.
[root@zod ~]# 



Steps to Reproduce:
==================
1.have a volume and create thousands of files  in cold tier and attach a tier such
2.now issue a detach tier start and wait for it to complete
3.now check the detach tier status, which will show as complete for each node.
But it can be seen that even without any files in hot tier, the files scanned will show as number of files in cold tier, which is wrong

Comment 1 Nag Pavan Chilakam 2015-09-11 15:24:16 UTC

sosreports

[root@rhsqe-repo sosreports]# chmod -R 0777 bug.1262417
[root@rhsqe-repo sosreports]# pwd
/home/repo/sosreports
[root@rhsqe-repo sosreports]# hostname
rhsqe-repo.lab.eng.blr.redhat.com
[root@rhsqe-repo sosreports]# ll bug.1262417
total 8
drwxrwsrwx. 2 root qe 4096 Sep 11 20:46 node1
drwxrwsrwx. 2 root qe 4096 Sep 11 20:46 node2

Comment 3 Kaushal 2017-03-08 10:53:43 UTC

This bug is getting closed because GlusteFS-3.7 has reached its end-of-life.

Note: This bug is being closed using a script. No verification has been performed to check if it still exists on newer releases of GlusterFS.
If this bug still exists in newer GlusterFS releases, please reopen this bug against the newer release.