[lttng-dev] Merge two LTTng CTF traces into one
Geneviève Bastien
gbastien at versatic.net
Tue Jan 6 11:28:35 EST 2015
Hi Divya,
I'm bringing this discussion back to lttng-dev, as it may benefit others
in the future.
You now have the right fields to synchronize traces. It uses packets of
type TCP and fields seq, ack_seq and flags to match packets.
But what are you trying to achieve exactly? The traces you sent me are
taken on the same machine at different times. They can never be
synchronized. Trace synchronization allows you to synchronize traces
taken at the same time on different machines (clocks) so that their
events can have the same reference clock.
You can apply a time offset to one of the traces so that their beginning
matches (Right-click on the experiment -> Apply time offset... More
documentation on this feature is available in the master code). If
that's what you want. Otherwise, please explain your specific need.
Geneviève
On 01/06/2015 01:33 AM, Divya Vyas wrote:
> Hi,
>
> I am attaching the traces . I tried to synchronize the traces of same
> machine but still quality is absent .
>
> I am in urgent need to get these traces synchronized .
>
> On Tue, Jan 6, 2015 at 11:00 AM, Divya Vyas <dvyas at mvista.com
> <mailto:dvyas at mvista.com>> wrote:
>
> Hi ,
>
> I tried again the steps.
>
> net_dev_queue: { cpu_id = 0 }, { skbaddr = 18446612135892807424,
> len = 98, name = "eth0", network_header = ( _nhtype_ip : container
> = 1 ), network_fields = { nhtype_ip = { ihl_version = 0x45, tos =
> 0, tot_len = 84, id = 0x560A, frag_off = 16384, ttl = 64, protocol
> = 0x1, checksum = 0xFFF4, saddr = 0xAA267D8, daddr = 0xAA2678E }
> }, transport_header = ( _thtype_none : container = 0 ),
> transport_fields = { thtype_none = { } } }
>
> net_dev_queue: { cpu_id = 0 }, { skbaddr = 18446612135892807424,
> len = 98, name = "eth0", network_header = ( _nhtype_ip : container
> = 1 ), network_fields = { nhtype_ip = { ihl_version = 0x45, tos =
> 0, tot_len = 84, id = 0x560A, frag_off = 16384, ttl = 64, protocol
> = 0x1, checksum = 0xFFF4, saddr = 0xAA267D8, daddr = 0xAA2678E }
> }, transport_header = ( _thtype_none : container = 0 ),
> transport_fields = { thtype_none = { } } }
>
>
> Is this kind of data should be added in the trace log ?
>
>
>
> On Tue, Jan 6, 2015 at 3:21 AM, Divya Vyas <dvyas at mvista.com
> <mailto:dvyas at mvista.com>> wrote:
>
> Hi,
>
> Can you please help me what kind of extra fields will be added
> in trace data. Because I think I followed all the steps.
>
> The branch I was not able to got ,getting some git error. So I
> downloaded snapshot from website.
>
> On Jan 5, 2015 9:14 PM, "Geneviève Bastien"
> <gbastien at versatic.net <mailto:gbastien at versatic.net>> wrote:
>
> Hi Divya,
>
> I looked at your traces and you do not seem to be using
> the 'net_data_experimental' special branch to get the
> extra fields for synchronization. You have the
> net_dev_queue and netif_receive_skb events, but they do
> not have the required fields to be able to synchronize.
> See the section "Obtain synchronizable traces" in
> http://help.eclipse.org/luna/index.jsp?topic=%2Forg.eclipse.linuxtools.lttng.help%2Fdoc%2FTrace-synchronization.html
> for how to compile with that branch.
>
> Geneviève
>
>
> On 12/28/2014 12:44 AM, Divya Vyas wrote:
>> Hi,
>>
>> I am getting Synchronization quality is absent. The
>> workload I am using is ssh and scp .
>>
>> I have attached the traces . Can you please look at it
>> and give em some advise where I am going wrong?
>>
>> Thanks,
>> Divya
>>
>> On Wed, Dec 24, 2014 at 1:54 AM, Geneviève Bastien
>> <gbastien at versatic.net <mailto:gbastien at versatic.net>> wrote:
>>
>> Hi Divya,
>>
>> If you followed the instructions in the help, then
>> you have compiled
>> LTTng-modules with the right tracepoints enabled on
>> all the machines you
>> want to synchronize. Which method did you choose?
>>
>> Make sure you enabled either
>> net_dev_queue/netif_receive_skb or
>> inet_sock_local_in/inet_sock_local_out on all
>> machines. Also make sure
>> all machines exchange TCP packets during the trace,
>> otherwise there will
>> be nothing to synchronize them on.
>>
>> When you say you are not getting anything, what do
>> you mean? Do you have
>> output in the Synchronization view? If the
>> synchronization was OK, but
>> nothing was found, you should get a Synchronization
>> Quality of "Absent".
>> If the output is empty, either you have long traces
>> and you didn't get
>> anything yet (there is no progress bar for the
>> synchronization yet). Or
>> you may have gotten an exception.
>>
>> Can you provide us with your traces so we can take a
>> closer look?
>>
>> Geneviève
>>
>>
>> On 14-12-23 02:40 PM, Matthew Khouzam wrote:
>> > So you have traces with network stuff, I would
>> suggest seeing what
>> > events are enabled in your trace. Maybe you are
>> missing some key events,
>> > maybe the synchronization worked and we're chasing
>> a ghost...
>> >
>> > I am ccing Genevieve Bastien, and Masoume
>> Jabbarifar, the two people who
>> > designed and implemented synchronisation.
>> >
>> > I am not as much an expert as I would like to be in
>> that field.
>> >
>> > For offsetting though, it's in tracecompass, the
>> next version of the
>> > Eclipse LTTng viewer
>> >
>> > Here is a link to the page.
>> > http://projects.eclipse.org/projects/tools.tracecompass
>> >
>> > On 14-12-23 12:19 AM, Divya Vyas wrote:
>> >> Hi,
>> >>
>> >> Is there any document which describes how to
>> synchronize the traces on
>> >> same machine as well as different machine (
>> setting offset also ) .
>> >>
>> >> I exported the two trace in experiment and clicked
>> on synchronize
>> >> traces . But not getting anything.
>> >>
>> >> I followed this page
>> >>
>> >>
>> http://help.eclipse.org/luna/index.jsp?topic=%2Forg.eclipse.linuxtools.lttng.help%2Fdoc%2FTrace-synchronization.html
>> >>
>> >> Thanks,
>> >> Divya
>> >>
>> >>
>> >>
>> >> On Mon, Dec 22, 2014 at 11:24 PM, Matthew Khouzam
>> >> <matthew.khouzam at ericsson.com
>> <mailto:matthew.khouzam at ericsson.com>
>> <mailto:matthew.khouzam at ericsson.com
>> <mailto:matthew.khouzam at ericsson.com>>>
>> >> wrote:
>> >>
>> >> Sorry, I was a little hasty in my reply. You
>> can export traces,
>> >> but not
>> >> experiments yet, this is a feature to expect
>> soon if people want it.
>> >>
>> >>
>> >> On 14-12-22 10:17 AM, Matthew Khouzam wrote:
>> >> > Michel has hit the nail on the head there.
>> >> >
>> >> > I would just like to add that one can export
>> an experiment in trace
>> >> > compass. This means that the two traces are
>> shipped in a zip
>> >> with the
>> >> > synchronization. You can also apply a
>> constant clock offset if
>> >> network
>> >> > events are unavailable. If you really really
>> want to make a CTF
>> >> trace as
>> >> > an output, perhaps look at the python bound
>> babeltrace?
>> >> >
>> >> > BR
>> >> >
>> >> > Matthew
>> >> >
>> >> >
>> >> > On 14-12-22 08:07 AM, Michel Dagenais wrote:
>> >> >> Normally, the two traces are stored
>> separately and they are
>> >> "merged"
>> >> >> at display time in TraceCompass. If they
>> were taken on the same
>> >> host,
>> >> >> they use the same clock and should be
>> naturally aligned. If
>> >> they come
>> >> >> from different hosts and you want very fine
>> symchronization,
>> >> you need
>> >> >> some communication events from which to
>> synchronize the traces. TCP
>> >> >> packet send and receive events are
>> typically used. If you want
>> >> to look
>> >> >> at two traces simultaneously, it normally
>> implies that the two are
>> >> >> related, the two nodes communicating
>> through the network.
>> >> >>
>> >> >>
>> >>
>> ------------------------------------------------------------------------
>> >> >>
>> >> >> Hi,
>> >> >>
>> >> >> Is there any way to merge the two CTF
>> traces and see them
>> >> in one
>> >> >> with trace synchronization ?
>> >> >>
>> >> >> How it is related to trace synchronization
>> using network
>> >> events ?
>> >> >>
>> >> >>
>> >> >> Thanks,
>> >> >> Divya
>> >> >>
>> >> >>
>> _______________________________________________
>> >> >> lttng-dev mailing list
>> >> >> lttng-dev at lists.lttng.org
>> <mailto:lttng-dev at lists.lttng.org>
>> <mailto:lttng-dev at lists.lttng.org
>> <mailto:lttng-dev at lists.lttng.org>>
>> >> >>
>> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
>> >> >>
>> >> >>
>> >> >>
>> >> >>
>> >> >> _______________________________________________
>> >> >> lttng-dev mailing list
>> >> >> lttng-dev at lists.lttng.org
>> <mailto:lttng-dev at lists.lttng.org>
>> <mailto:lttng-dev at lists.lttng.org
>> <mailto:lttng-dev at lists.lttng.org>>
>> >> >>
>> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
>> >> >
>> >> > _______________________________________________
>> >> > lttng-dev mailing list
>> >> > lttng-dev at lists.lttng.org
>> <mailto:lttng-dev at lists.lttng.org>
>> <mailto:lttng-dev at lists.lttng.org
>> <mailto:lttng-dev at lists.lttng.org>>
>> >> >
>> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
>> >>
>> >>
>> >> _______________________________________________
>> >> lttng-dev mailing list
>> >> lttng-dev at lists.lttng.org
>> <mailto:lttng-dev at lists.lttng.org>
>> <mailto:lttng-dev at lists.lttng.org
>> <mailto:lttng-dev at lists.lttng.org>>
>> >>
>> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
>> >>
>> >>
>>
>>
>>
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.lttng.org/pipermail/lttng-dev/attachments/20150106/5b4bc7ba/attachment-0001.html>
More information about the lttng-dev
mailing list