Welcome Jonathan,
Also, for people seeking great babeltrace support, I feel I should plug the lttng-dev mailinglist. I hope the URL is not censored. https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev if it is, just search for "lttng-dev -- LTTng development list" lttng-dev Info Page<https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev> lists.lttng.org To see the collection of prior postings to the list, visit the lttng-dev Archives.. Using lttng-dev: To post a message to all the list members, send email to lttng-dev@lists.lttng.org. You can subscribe to the list, or change your existing subscription, in the sections below. ________________________________ From: Jonathan Rajotte-Julien <jonathan.rajotte-jul...@efficios.com> Sent: Tuesday, March 12, 2019 11:03:14 AM To: Doug Schaefer; tracecompass developer discussions Cc: Matthew Khouzam; lttng-dev Subject: Re: [tracecompass-dev] Scalability Hi Doug, On Tue, Mar 12, 2019 at 02:56:26PM +0000, Doug Schaefer wrote: > Thanks, Matthew, I ended up flushing every 100K events and that seemed OK. > > My biggest worry is on the read side. Babeltrace blew up on that file. It's a > pretty simple trace (for now) with a single event class with 4 ints and a > sequence of 32-bit unsigned ints which is usually only 2 elements long. This is not I expect. Still eithet jgalar or eep might have a more insight on this. CCing the lttng-dev mailing list. Is there any way to share us a similar trace? Either with a generator or we can provide a link for you to upload it. The current limit on bugs.lttng.org is a bit too small for such trace. > > Aside from that, am very pleased with the how easy CTF is to work with. > Looking forward to doing more. > > Doug. > > On Tue, 2019-03-12 at 14:41 +0000, Matthew Khouzam wrote: > > Hi Doug, > > > Great to hear you're coming to a standard! I don't know if trace compass will > scale properly as I don't know what the trace configuration is. > > > > I have one of our trace which has 16 million events, the size of each event > > is around 32 bytes giving me a 540MB file. My first attempt at simply > > writing out the CTF events without a flush ran out of virtual memory. I > > then flushed after every event which made each event take 32K. So I found a > > middle ground and the resulting stream file is close to the same size. > > > > My suggestion is to have 1 MB packets. This makes seeking very efficient. If > each event is 32 bytes, basically flush every 25k events or so. > > > Please keep us posted! > > > Matthew. > > ________________________________ > From: tracecompass-dev-boun...@eclipse.org > <tracecompass-dev-boun...@eclipse.org> on behalf of Doug Schaefer > <dschae...@blackberry.com> > Sent: Tuesday, March 12, 2019 10:30:15 AM > To: tracecompass-...@eclipse.org > Subject: [tracecompass-dev] Scalability > > Hey gang, > > We're finally starting to look at converting our custom traces into CTF so we > can leverage tools like TraceCompass and, of course, contribute to it. One > thing I quickly ran into is a scalability issue I'm seeing with libbabeltrace. > > I have one of our trace which has 16 million events, the size of each event > is around 32 bytes giving me a 540MB file. My first attempt at simply writing > out the CTF events without a flush ran out of virtual memory. I then flushed > after every event which made each event take 32K. So I found a middle ground > and the resulting stream file is close to the same size. > > But when I use babeltrace to print it out, I ran out of virtual memory. I > then hand coded a reader and simply adding the trace to the context caused > the memory issue. It really looks like libbabeltrace (version 1.5 from the > Ubuntu 18.04 distro), tries to inflate the events into it's internal > representation for the entire trace. I need to do more investigation to > confirm that. > > So my question for this list, would TraceCompass do better? Does it have it's > own parsing libraries? > > Thanks, > Doug > _______________________________________________ > tracecompass-dev mailing list > tracecompass-...@eclipse.org > To change your delivery options, retrieve your password, or unsubscribe from > this list, visit > https://www.eclipse.org/mailman/listinfo/tracecompass-dev -- Jonathan Rajotte-Julien EfficiOS
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