[LU-2396] ofd brw_stats not maintained Created: 27/Nov/12  Updated: 08/May/13  Resolved: 22/Mar/13

Status: Resolved
Project: Lustre
Component/s: None
Affects Version/s: Lustre 2.4.0
Fix Version/s: Lustre 2.4.0

Type: Bug Priority: Minor
Reporter: John Hammond Assignee: Keith Mannthey (Inactive)
Resolution: Fixed Votes: 0
Labels: ofd, patch, procfs

Issue Links:
Related
is related to LU-3300 Restore missing proc information for LMT Open
Severity: 3
Rank (Obsolete): 5686

 Description   

The per-ofd and per-export brw_stats are not maintained although the proc files still exist (see /proc/fs/lustre/obdfilter//brw_stats and /proc/fs/lustre/obdfilter//exports/*/brw_stats). Since filter_iobuf is now osd_iobuf, down one layer and without access to the export, it would be difficult to restore maintenance of these files.

The per-ofd brw_stats file could be replaced with a symlink to ../../osd-whatever/whoever/brw_stats (as in the patch for LU-2358) but there doesn't seem to be consensus that doing so is the Right Thing.



 Comments   
Comment by John Hammond [ 27/Nov/12 ]

Please see http://review.whamcloud.com/4689.

Comment by Andreas Dilger [ 30/Nov/12 ]

Alex, what do you think about symlinking the brw_stats from the old location in /proc/fs/lustre/obdfilter/*/brw_stats to osd?

My preference would be that we DO have the symlink, so that tools that monitor these stats can find them in the same place at least across a couple of releases, and eventually they can move to get the stats from osd-* once there are a few versions that have them there.

Moving forward, I'd prefer to break up brw_stats into separate stats files, or at least transform it into YAML that can be parsed more easily, since the ASCII art layout is a mess for parsing.

Comment by Alex Zhuravlev [ 04/Dec/12 ]

I'm fine with few symlinks from obdfilter to osd. this is already proven to be clear and trivial to implement.

Comment by Alex Zhuravlev [ 04/Dec/12 ]

hm, just read more carefully.. symlinks to export per-ofd stats are trivial, but John's question was also about per-export brw_stats and I agree it won't be that trivial to maintain. Andreas, do you think we need to preserve per-export brw_stats?

Comment by Andreas Dilger [ 05/Dec/12 ]

Alex, do you think that adding and removing a symlink in the per-export directory is more complex than adding it for the whole device? Something like "../osd/exports/

{nid}

/brw_stats" for each ofd export.

I agree that it is less critical than the main brw_stats, but I have no idea how much these files are used or not.

Comment by Peter Jones [ 22/Mar/13 ]

Landed for 2.4

Generated at Sat Feb 10 01:24:51 UTC 2024 using Jira 9.4.14#940014-sha1:734e6822bbf0d45eff9af51f82432957f73aa32c.