[LU-11] Lustre 2.x functionality regression: Missing aggregate MDT stats

Fri, 12 Nov 2010 17:58:39 +0000

LLNL has pointed out that LMT performance at scale (e.g. 20k clients) will greatly suffer if LMT has to read the per-client-export stats in order to recreate the missing aggregate MDT stats. By extension, any other monitoring tools depending on aggregate MDT stats will also be affected by this regression.

----- Forwarded message from Brian Behlendorf <behlendorf1@llnl.gov> -----

Date: Tue, 2 Nov 2010 14:43:49 -0700
From: Brian Behlendorf <behlendorf1@llnl.gov>
To: Jim Garlick <garlick@llnl.gov>
Subject: Re: [mjmac@whamcloud.com: Re: LMT work]

Check out bug 21420 comment #40, specifically commit 9eb3d1db in HEAD.
This is where they moved the stats from being global to being
per-export, they appear to think they were useless.

commit 9eb3d1db42d2937daef25950f6527ccb46221f8e
Author: LiuYing <emoly.liu@sun.com>
Date: Fri Oct 8 10:48:14 2010 +0800

b=21420 Add mds/mgs stats to HEAD

1)remove useless counter from mds and move some definitions
from mds to mdt;
2)move LPROCFS_MD_OP_INITs from lprocfs_alloc_md_stats() to
lprocfs_init_mps_stats(), which is needed by this stats;
3)increase mdt counter for each type operation

i=andreas
i=wangdi

Whamcloud Community JIRA

[LU-11] Lustre 2.x functionality regression: Missing aggregate MDT stats