Bug 1257911 - add policy mechanism for promotion and demotion
Summary: add policy mechanism for promotion and demotion
Keywords:
Status: CLOSED CURRENTRELEASE
Alias: None
Product: GlusterFS
Classification: Community
Component: tiering
Version: mainline
Hardware: Unspecified
OS: Unspecified
unspecified
unspecified
Target Milestone: ---
Assignee: Dan Lambright
QA Contact: bugs@gluster.org
URL:
Whiteboard:
Depends On:
Blocks: 1260923 1270527 1271757
TreeView+ depends on / blocked
 
Reported: 2015-08-28 11:37 UTC by Dan Lambright
Modified: 2016-06-16 13:34 UTC (History)
2 users (show)

Fixed In Version: glusterfs-3.8rc2
Doc Type: Bug Fix
Doc Text:
Clone Of:
: 1270527 1271757 (view as bug list)
Environment:
Last Closed: 2016-06-16 13:34:27 UTC
Regression: ---
Mount Type: ---
Documentation: ---
CRM:
Verified Versions:
Embargoed:


Attachments (Terms of Use)

Description Dan Lambright 2015-08-28 11:37:55 UTC
Current mechanism for driving promotion/demotion is too rigorous. Fils are demoted automatically and the hot tier will be underutilized. Need a more flexible system that can be tuned according to customers needs according to various parameters. Need to gracefully handle situations where the hot tier becomes full.

Comment 1 Anand Avati 2015-08-28 11:39:39 UTC
REVIEW: http://review.gluster.org/12039 (cluster/tier: WIP add watermarks and policy driver) posted (#1) for review on master by Dan Lambright (dlambrig)

Comment 2 Anand Avati 2015-08-28 20:53:20 UTC
REVIEW: http://review.gluster.org/12039 (cluster/tier: WIP add watermarks and policy driver) posted (#2) for review on master by Dan Lambright (dlambrig)

Comment 3 Anand Avati 2015-09-01 16:31:59 UTC
REVIEW: http://review.gluster.org/12039 (cluster/tier: WIP add watermarks and policy driver) posted (#3) for review on master by Dan Lambright (dlambrig)

Comment 4 Vijay Bellur 2015-09-03 21:30:17 UTC
REVIEW: http://review.gluster.org/12039 (cluster/tier: WIP add watermarks and policy driver) posted (#4) for review on master by Dan Lambright (dlambrig)

Comment 5 Vijay Bellur 2015-09-08 21:01:37 UTC
REVIEW: http://review.gluster.org/12039 (cluster/tier: WIP add watermarks and policy driver) posted (#5) for review on master by Dan Lambright (dlambrig)

Comment 6 Vijay Bellur 2015-09-10 21:56:30 UTC
REVIEW: http://review.gluster.org/12039 (cluster/tier: add watermarks and policy driver) posted (#6) for review on master by Dan Lambright (dlambrig)

Comment 7 Vijay Bellur 2015-09-12 00:37:14 UTC
REVIEW: http://review.gluster.org/12039 (cluster/tier: add watermarks and policy driver) posted (#7) for review on master by Dan Lambright (dlambrig)

Comment 8 Vijay Bellur 2015-09-18 05:29:54 UTC
REVIEW: http://review.gluster.org/12039 (cluster/tier: add watermarks and policy driver) posted (#8) for review on master by Dan Lambright (dlambrig)

Comment 9 Vijay Bellur 2015-10-10 00:46:29 UTC
REVIEW: http://review.gluster.org/12039 (cluster/tier: add watermarks and policy driver) posted (#24) for review on master by Dan Lambright (dlambrig)

Comment 10 Vijay Bellur 2015-10-10 13:00:08 UTC
COMMIT: http://review.gluster.org/12039 committed in master by Dan Lambright (dlambrig) 
------
commit 672baab88fb7f32e844cd4be22e0924e4e0e83fc
Author: Dan Lambright <dlambrig>
Date:   Fri Sep 18 00:49:06 2015 -0400

    cluster/tier: add watermarks and policy driver
    
    This fix introduces infrastructure to support different
    policies for promotion and demotion.
    
    Currently the tier feature automatically promotes and demotes
    files periodically based on access. This is good for testing
    but too stringent for most real workloads. It makes it
    difficult to fully utilize a hot tier- data will be demoted
    before it is touched- its unlikely a 100GB hot SSD will have
    all its data touched in a window of time.
    
    A new parameter "mode" allows the user to pick promotion/demotion
    polcies.
    
    The "test mode" will be used for *.t and other general testing.
    This is the current mechanism.
    
    The "cache mode" introduces watermarks. The watermarks
    represent levels of data residing on the hot tier.
    
    "cache mode" policy:
    
    The % the hot tier is full is called P.
    
    Do not promote or demote more than D MB or F files.
    
    A random number [0-100] is called R.
    
    Rules for migration:
    
    if (P < watermark_low) don't demote, always promote.
    
    if (P >= watermark_low) && (P < watermark_hi) demote if R < P; promote if R > P.
    
    if (P > watermark_hi) always demote, don't promote.
    
    gluster volume set {vol} cluster.watermark-hi %
    gluster volume set {vol} cluster.watermark-low %
    gluster volume set {vol} cluster.tier-max-mb {D}
    gluster volume set {vol} cluster.tier-max-files {F}
    gluster volume set {vol} cluster.tier-mode {test|cache}
    
    Change-Id: I157f19667ec95aa1d53406041c1e3b073be127c2
    BUG: 1257911
    Signed-off-by: Dan Lambright <dlambrig>
    Reviewed-on: http://review.gluster.org/12039
    Tested-by: Gluster Build System <jenkins.com>
    Reviewed-by: Atin Mukherjee <amukherj>

Comment 11 Niels de Vos 2016-06-16 13:34:27 UTC
This bug is getting closed because a release has been made available that should address the reported issue. In case the problem is still not fixed with glusterfs-3.8.0, please open a new bug report.

glusterfs-3.8.0 has been announced on the Gluster mailinglists [1], packages for several distributions should become available in the near future. Keep an eye on the Gluster Users mailinglist [2] and the update infrastructure for your distribution.

[1] http://blog.gluster.org/2016/06/glusterfs-3-8-released/
[2] http://thread.gmane.org/gmane.comp.file-systems.gluster.user


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