Bug 1278754 - Data Tiering:Metadata changes to a file should not heat/promote the file
Summary: Data Tiering:Metadata changes to a file should not heat/promote the file
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Red Hat Gluster Storage
Classification: Red Hat Storage
Component: tier
Version: rhgs-3.1
Hardware: Unspecified
OS: Unspecified
urgent
urgent
Target Milestone: ---
: RHGS 3.1.2
Assignee: Joseph Elwin Fernandes
QA Contact: Nag Pavan Chilakam
URL:
Whiteboard:
Depends On:
Blocks: 1260783 1260923 1279166 1282315
TreeView+ depends on / blocked
 
Reported: 2015-11-06 11:06 UTC by Nag Pavan Chilakam
Modified: 2016-09-17 15:36 UTC (History)
6 users (show)

Fixed In Version: glusterfs-3.7.5-7
Doc Type: Bug Fix
Doc Text:
Clone Of:
: 1279166 (view as bug list)
Environment:
Last Closed: 2016-03-01 05:53:31 UTC
Embargoed:


Attachments (Terms of Use)
qe verification log (205.54 KB, text/plain)
2015-11-25 10:26 UTC, Nag Pavan Chilakam
no flags Details


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHBA-2016:0193 0 normal SHIPPED_LIVE Red Hat Gluster Storage 3.1 update 2 2016-03-01 10:20:36 UTC

Description Nag Pavan Chilakam 2015-11-06 11:06:17 UTC
Description of problem:
======================
Currently we are heating the file and promoting a file if chnages are made to the metadata of the file, eg chnaging file permission, changing times,etc
This is actually a tiering feature and heating files for metadata changes is not the right thing to do.
Only data read or writes should promote files. 
metadata read/changes must not promote a file


Version-Release number of selected component (if applicable):
================================================================
[root@zod ~]# rpm -qa|grep gluster
glusterfs-libs-3.7.5-5.el7rhgs.x86_64
glusterfs-fuse-3.7.5-5.el7rhgs.x86_64
glusterfs-3.7.5-5.el7rhgs.x86_64
glusterfs-server-3.7.5-5.el7rhgs.x86_64
glusterfs-client-xlators-3.7.5-5.el7rhgs.x86_64
glusterfs-cli-3.7.5-5.el7rhgs.x86_64
glusterfs-api-3.7.5-5.el7rhgs.x86_64
glusterfs-debuginfo-3.7.5-5.el7rhgs.x86_64


How reproducible:
====================
always

Steps to Reproduce:
=================
1.create a volume and have some files
2.now attach tier and turn on ctr
3.now make some metadata changes to  the file like, changing permission of the cold files or touch the file to change the atime/ctime/mtime of the file


Actual results:
===============
it can be seen that these Ops heat the file

Expected results:
==================
we should not be heating files when metadata changes, as this is not the real use case of tiering. Tiering is to promote files where data changes are happening frequently so that users can make those read/writes faster

Comment 3 Nag Pavan Chilakam 2015-11-25 10:23:17 UTC
Ran the following cases on glusterfs-3.7.5-7 build.
1)In cache mode:
> for files in cold tier(legacy)made modifications to file permissions, times like atime to see if the file was getting heated. Files were not getting heated with any of the metadata changes as the db was not anyway increasing the counts. Hence files were not getting promoted
>for files in hot tier, even if they are being any metadata changes as above, files are getting demoted when no file data access happens
2)in test mode:
>made modifications to file permissions, times like atime to see if the file was getting heated. Files were not getting heated with any of the metadata changes as the db was not anyway increasing the counts
>for files in hot tier, even if they are being any metadata changes as above, files are getting demoted when no file data access happens

Turned on counters and set the read and write threshold to 2, file metadata opertaions were not increasing the count.


Hence working as expected. Moving the bug to verified:


Logs are attached

=====================

Comment 4 Nag Pavan Chilakam 2015-11-25 10:26:19 UTC
Created attachment 1098682 [details]
qe verification log

Comment 6 errata-xmlrpc 2016-03-01 05:53:31 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://rhn.redhat.com/errata/RHBA-2016-0193.html


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