Lustre devel - May 2007 - [Bug 11089] per-nid client statistics

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using the following link:
https://bugzilla.lustre.org/show_bug.cgi?id=11089



cc''ing this comment to lustre-devel, referring to changing the
per-export stats
on the servers to per-nid stats. Per-nid stats would be persistent across client
disconnections.

(In reply to comment #56)
> OK, new thought - forget the per-export stats, and only use the per-nid
stats.
> Most of the time they will be duplicates of each other anyhow, with the
main
> difference being that the per-export stats are destroyed when a client
> disconnects.
> 
> New structure:
> +- exports
>     |
>     +- nid#1
>     |   |
>     |   + stats
>     |   |
>     |   + uuids
>     |
>     +- nid#2...
>     +- clear
> 
> The "uuid"s file would list the uuids of _active_ exports, so if
there was
> nothing connected from that nid at the moment, the uuids file would be
empty.
> (That way people can easily see if the nid is "stale".)
> 
> The other thing we should do is have a way to clear all the stale nids, so
I
> propose echoing a 0 into a new file "clear" under the exports
directory.  This
> will erase any nid subdir that is not currently in use, and reset the stats
of
> any nid that is in use.

Please don''t reply to lustre-devel. Instead, comment in Bugzilla by
using the following link:
https://bugzilla.lustre.org/show_bug.cgi?id=11089



(In reply to comment #58)
> What is critical is that the stats ARE cleaned up automatically and not
only
> when someone pokes the "clear" file.  In the past we''ve
hit the 32768-client
> limit pretty easily on large XT clusters if the llrd eviction is broken.
Ah, but that wouldn''t result in 32768 nids (dirs or stats).  We would
simply be
reusing the stats files from previous connections from the same nid.  Whenever
the actual exports that contribute to the nid stats get cleaned up, we just need
to remove them from the per-nid stats list.