From: compudj@krystal.dyndns.org (Mathieu Desnoyers)
Subject: [ltt-dev] how to use lttng in large workload with long time
Date: Thu, 28 Jan 2010 09:04:15 -0500 [thread overview]
Message-ID: <20100128140415.GC15776@Krystal> (raw)
In-Reply-To: <1264649732.3856.74.camel@licj-pc>
* Li, Chanjuan (lichanjuan04 at gmail.com) wrote:
> hi,all:
> Now I want to use lttng to analyse performance of a MPI application
> on wether forecast. The application will run about 2h. When I use lttng
> to collect events, it generates 50G results . It is hard to analyse with
> such huge data.
Is LTTV having problems with those 50GB of data ?
> So I want to reduce the events to be recorded instead of
> ltt-armall events.
> I try ltt-armtap, but it does not work because there is no /proc/ltt in
> my machine. In addtion, I read the LTTng manual, there is a flight
> record mode. I want to know that could help in such context. thanks in
> advance!
Flight recorder mode:
You can configure tracing in flight recorder mode. The trace session
will only write events into a trace buffer in memory, without saving the
trace to disk. So the oldest events will be constantly overwritten.
If you know a particular behavior or problem in your application you are
looking for (a trigger), then you can keep flight recorder tracing
active for the whole 2 hours, but only save snapshots when the situation
you are looking for happens.
Mathieu
>
>
>
>
> best regards
>
> lily
>
>
> _______________________________________________
> ltt-dev mailing list
> ltt-dev at lists.casi.polymtl.ca
> http://lists.casi.polymtl.ca/cgi-bin/mailman/listinfo/ltt-dev
>
--
Mathieu Desnoyers
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68
prev parent reply other threads:[~2010-01-28 14:04 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-28 3:35 Li, Chanjuan
2010-01-28 14:04 ` Mathieu Desnoyers [this message]
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