[LU-11052] remove obd ops based stats

• Type: Improvement
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.12.0
• Assignee: WC Triage
• Reporter: John Hammond

Description

Stats maintained via the obd operations wrappers are less and less interesting. We should remove them.

Comments

[Peter Jones]

Landed for 2.12

[Gerrit Updater]

Oleg Drokin ([e-mail]) merged in patch https://review.whamcloud.com/32602/
Subject: LU-11052 obd: remove OBD ops based stats
Project: fs/lustre-release
Branch: master
Current Patch Set:
Commit: 711eff3a50003b5c617955bae50fba7bfcb9c43d

[Gerrit Updater]

John L. Hammond ([e-mail]) uploaded a new patch: https://review.whamcloud.com/32602
Subject: LU-11052 obd: remove OBD ops based stats
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: 3b9fe7e0f33d42525ecc604ceb6d066dd09c0586

[John Hammond]

The only stats files affected here would be obdfilter.*.stats, obdfilter.*.exports.*.stats and obdecho.*.stats. For obdfilter here is a comparison for two racer runs. With the current obd ops based stats:

# lctl get_param obdfilter.lustre-OST0000.stats
obdfilter.lustre-OST0000.stats=
snapshot_time             1527267354.328068245 secs.nsecs
read_bytes                610 samples [bytes] 4096 4194304 800043008
write_bytes               2196 samples [bytes] 5 4194304 3410224606
setattr                   13545 samples [reqs]
punch                     7682 samples [reqs]
destroy                   2281 samples [reqs]
create                    74 samples [reqs]
statfs                    234 samples [reqs]
get_info                  1 samples [reqs]
connect                   3 samples [reqs]
disconnect                1 samples [reqs]
preprw                    2806 samples [reqs]
commitrw                  2806 samples [reqs]
ping                      422 samples [reqs]

# lctl get_param obdfilter.lustre-OST0000.exports.*.stats
[e-mail]=
snapshot_time             1527267369.060990116 secs.nsecs
read_bytes                610 samples [bytes] 4096 4194304 800043008
write_bytes               2196 samples [bytes] 5 4194304 3410224606
setattr                   13545 samples [reqs]
punch                     7682 samples [reqs]
destroy                   2281 samples [reqs]
create                    74 samples [reqs]
statfs                    237 samples [reqs]
get_info                  1 samples [reqs]
disconnect                1 samples [reqs]
preprw                    2806 samples [reqs]
commitrw                  2806 samples [reqs]
ping                      428 samples [reqs]

And after the OBD ops bases stats have been removed:

# lctl get_param obdfilter.lustre-OST0000.stats
obdfilter.lustre-OST0000.stats=
snapshot_time             1527168813.867472974 secs.nsecs
read_bytes                200 samples [bytes] 4096 4194304 231366656
write_bytes               1703 samples [bytes] 5 4194304 1220864892
getattr                   337 samples [reqs]
setattr                   6358 samples [reqs]
punch                     2880 samples [reqs]
destroy                   2000 samples [reqs]
create                    71 samples [reqs]
statfs                    2148 samples [reqs]
get_info                  4 samples [reqs]

# lctl get_param obdfilter.lustre-OST0000.exports.*.stats
[e-mail]=
snapshot_time             1527168830.966629150 secs.nsecs
read_bytes                182 samples [bytes] 4096 4194304 134897664
write_bytes               1710 samples [bytes] 5 4194304 1198540888
getattr                   335 samples [reqs]
setattr                   6703 samples [reqs]
punch                     3017 samples [reqs]
destroy                   2000 samples [reqs]
create                    71 samples [reqs]
statfs                    2160 samples [reqs]
get_info                  4 samples [reqs]

So the difference it that after we drop connect, disconnect, preprw, commitrw, and ping.

I did not try to create and use a target of type obdecho. So I don't have any comparison to show.

[John Hammond]

I'll preparing a comment to post here and in the commit message about what differences we'll see in the proc files.

[James A Simmons]

You are my hero. I was just looking at tackling that work but have lacked the cycles to start it. Please be aware that some sites do collect this data to study it so remove with care.