* iostat "await" like counter for measuring nfs latency
@ 2010-07-27 10:07 Or Gerlitz
2010-07-27 15:27 ` Trond Myklebust
0 siblings, 1 reply; 6+ messages in thread
From: Or Gerlitz @ 2010-07-27 10:07 UTC (permalink / raw)
To: Trond Myklebust; +Cc: linux-nfs
Doing some iscsi and nfs performance testing, I realized that iostat(1)
doesn't support an "await" (*) like counter for measuring nfs latency.
Can tracking nfs latency be done in other means? is there a plan to
extend the nfs iostats code to include such/similar counter?
thanks,
Or.
(*) await - The average time (in milliseconds) for I/O requests issued
to the device to be served. This includes the time spent by the
requests in queue and the time spent servicing them.
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: iostat "await" like counter for measuring nfs latency 2010-07-27 10:07 iostat "await" like counter for measuring nfs latency Or Gerlitz @ 2010-07-27 15:27 ` Trond Myklebust 2010-07-28 9:45 ` Or Gerlitz 0 siblings, 1 reply; 6+ messages in thread From: Trond Myklebust @ 2010-07-27 15:27 UTC (permalink / raw) To: Or Gerlitz; +Cc: linux-nfs On Tue, 2010-07-27 at 13:07 +0300, Or Gerlitz wrote: > Doing some iscsi and nfs performance testing, I realized that iostat(1) > doesn't support an "await" (*) like counter for measuring nfs latency. > > Can tracking nfs latency be done in other means? is there a plan to > extend the nfs iostats code to include such/similar counter? > > thanks, > > Or. > > > (*) await - The average time (in milliseconds) for I/O requests issued > to the device to be served. This includes the time spent by the > requests in queue and the time spent servicing them. > > The information is already available in /proc/self/mountstats. It is up to iostat to start using it. Trond ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: iostat "await" like counter for measuring nfs latency 2010-07-27 15:27 ` Trond Myklebust @ 2010-07-28 9:45 ` Or Gerlitz 2010-07-28 17:40 ` Chuck Lever 0 siblings, 1 reply; 6+ messages in thread From: Or Gerlitz @ 2010-07-28 9:45 UTC (permalink / raw) To: Sebastien Godard; +Cc: Trond Myklebust, linux-nfs Trond Myklebust wrote: > On Tue, 2010-07-27 at 13:07 +0300, Or Gerlitz wrote: >> Doing some iscsi and nfs performance testing, I realized that iostat(1) >> doesn't support an "await" like counter for measuring nfs latency. >> Can tracking nfs latency be done in other means? is there a plan to >> extend the nfs iostats code to include such/similar counter? > The information is already available in /proc/self/mountstats. It is up > to iostat to start using it. Sebastian, is there a plan to support await like counter in sysstat? I didn't find a source repository (is there an open one? where?) so downloaded the latest code (version 9.1.3) drop from the website and couldn't see there such a counter, am I missing something? Or. ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: iostat "await" like counter for measuring nfs latency 2010-07-28 9:45 ` Or Gerlitz @ 2010-07-28 17:40 ` Chuck Lever 2010-07-28 19:21 ` Sebastien Godard 0 siblings, 1 reply; 6+ messages in thread From: Chuck Lever @ 2010-07-28 17:40 UTC (permalink / raw) To: Or Gerlitz; +Cc: Sebastien Godard, Trond Myklebust, linux-nfs On 07/28/10 05:45 AM, Or Gerlitz wrote: > Trond Myklebust wrote: >> On Tue, 2010-07-27 at 13:07 +0300, Or Gerlitz wrote: >>> Doing some iscsi and nfs performance testing, I realized that iostat(1) >>> doesn't support an "await" like counter for measuring nfs latency. >>> Can tracking nfs latency be done in other means? is there a plan to >>> extend the nfs iostats code to include such/similar counter? > >> The information is already available in /proc/self/mountstats. It is up >> to iostat to start using it. > > Sebastian, is there a plan to support await like counter in sysstat? > > I didn't find a source repository (is there an open one? where?) so > downloaded the latest code (version 9.1.3) drop from the website and > couldn't see there such a counter, am I missing something? There are Python scripts in nfs-utils that report the statistics in /proc/self/mountstats. Nobody really likes the file format of /proc/self/mountstats, so the plan is to move these, at some point, to someplace where perf can report them. At that point, iostat support would also be nice. ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: iostat "await" like counter for measuring nfs latency 2010-07-28 17:40 ` Chuck Lever @ 2010-07-28 19:21 ` Sebastien Godard 2010-07-29 15:53 ` Chuck Lever 0 siblings, 1 reply; 6+ messages in thread From: Sebastien Godard @ 2010-07-28 19:21 UTC (permalink / raw) To: Or Gerlitz; +Cc: Chuck Lever, Trond Myklebust, linux-nfs On 07/28/2010 07:40 PM, Chuck Lever wrote: > > On 07/28/10 05:45 AM, Or Gerlitz wrote: >> Trond Myklebust wrote: >>> On Tue, 2010-07-27 at 13:07 +0300, Or Gerlitz wrote: >>>> Doing some iscsi and nfs performance testing, I realized that >>>> iostat(1) >>>> doesn't support an "await" like counter for measuring nfs latency. >>>> Can tracking nfs latency be done in other means? is there a plan to >>>> extend the nfs iostats code to include such/similar counter? >> >>> The information is already available in /proc/self/mountstats. It is up >>> to iostat to start using it. >> >> Sebastian, is there a plan to support await like counter in sysstat? >> >> I didn't find a source repository (is there an open one? where?) so >> downloaded the latest code (version 9.1.3) drop from the website and >> couldn't see there such a counter, am I missing something? > > There are Python scripts in nfs-utils that report the statistics in > /proc/self/mountstats. Nobody really likes the file format of > /proc/self/mountstats, so the plan is to move these, at some point, to > someplace where perf can report them. > > At that point, iostat support would also be nice. > I'm ready to accept a patch that would add an await like counter to measure NFS latency. BTW beginning with sysstat version 9.1.3, there is a specific command ("nfsiostat") aimed at displaying stats for network filesystems. Regards, -- Sébastien Godard (sysstat<at> orange.fr) Help support sysstat...! Visit http://pagesperso-orange.fr/sebastien.godard/ ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: iostat "await" like counter for measuring nfs latency 2010-07-28 19:21 ` Sebastien Godard @ 2010-07-29 15:53 ` Chuck Lever 0 siblings, 0 replies; 6+ messages in thread From: Chuck Lever @ 2010-07-29 15:53 UTC (permalink / raw) To: Sebastien Godard; +Cc: Or Gerlitz, Trond Myklebust, linux-nfs On 07/28/10 03:21 PM, Sebastien Godard wrote: > On 07/28/2010 07:40 PM, Chuck Lever wrote: >> >> On 07/28/10 05:45 AM, Or Gerlitz wrote: >>> Trond Myklebust wrote: >>>> On Tue, 2010-07-27 at 13:07 +0300, Or Gerlitz wrote: >>>>> Doing some iscsi and nfs performance testing, I realized that >>>>> iostat(1) >>>>> doesn't support an "await" like counter for measuring nfs latency. >>>>> Can tracking nfs latency be done in other means? is there a plan to >>>>> extend the nfs iostats code to include such/similar counter? >>> >>>> The information is already available in /proc/self/mountstats. It is up >>>> to iostat to start using it. >>> >>> Sebastian, is there a plan to support await like counter in sysstat? >>> >>> I didn't find a source repository (is there an open one? where?) so >>> downloaded the latest code (version 9.1.3) drop from the website and >>> couldn't see there such a counter, am I missing something? >> >> There are Python scripts in nfs-utils that report the statistics in >> /proc/self/mountstats. Nobody really likes the file format of >> /proc/self/mountstats, so the plan is to move these, at some point, to >> someplace where perf can report them. >> >> At that point, iostat support would also be nice. >> > > I'm ready to accept a patch that would add an await like counter to > measure NFS latency. What is await, precisely? And, by "NFS latency" do you mean read/write latency or something else? For NFS, even stat() can require server interaction (ie is not served from the system's local memory) > BTW beginning with sysstat version 9.1.3, there is a specific command > ("nfsiostat") aimed at displaying stats for network filesystems. ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2010-07-29 15:54 UTC | newest] Thread overview: 6+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2010-07-27 10:07 iostat "await" like counter for measuring nfs latency Or Gerlitz 2010-07-27 15:27 ` Trond Myklebust 2010-07-28 9:45 ` Or Gerlitz 2010-07-28 17:40 ` Chuck Lever 2010-07-28 19:21 ` Sebastien Godard 2010-07-29 15:53 ` Chuck Lever
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