* Re: Merge two LTTng CTF traces into one
[not found] <1431870336.8158578.1419253660346.JavaMail.root@polymtl.ca>
@ 2014-12-22 15:17 ` Matthew Khouzam
[not found] ` <549835FE.8090508@ericsson.com>
1 sibling, 0 replies; 11+ messages in thread
From: Matthew Khouzam @ 2014-12-22 15:17 UTC (permalink / raw)
To: lttng-dev
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@lists.lttng.org
> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
>
>
>
>
> _______________________________________________
> lttng-dev mailing list
> lttng-dev@lists.lttng.org
> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: Merge two LTTng CTF traces into one
[not found] ` <549835FE.8090508@ericsson.com>
@ 2014-12-22 17:54 ` Matthew Khouzam
[not found] ` <54985ACE.1000502@ericsson.com>
1 sibling, 0 replies; 11+ messages in thread
From: Matthew Khouzam @ 2014-12-22 17:54 UTC (permalink / raw)
To: lttng-dev
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@lists.lttng.org
>> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
>>
>>
>>
>>
>> _______________________________________________
>> lttng-dev mailing list
>> lttng-dev@lists.lttng.org
>> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
>
> _______________________________________________
> lttng-dev mailing list
> lttng-dev@lists.lttng.org
> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
^ permalink raw reply [flat|nested] 11+ messages in thread
* Fwd: Merge two LTTng CTF traces into one
[not found] ` <CA+=dQ-8+ZWXna=kMxQ0o6ypu2=cTURjE3A4h_uEFnbNctFdfxA@mail.gmail.com>
@ 2015-01-05 7:33 ` Divya Vyas
0 siblings, 0 replies; 11+ messages in thread
From: Divya Vyas @ 2015-01-05 7:33 UTC (permalink / raw)
To: lttng-dev
[-- Attachment #1.1: Type: text/plain, Size: 608 bytes --]
Hi,
I followed all the steps in the below link but I am not getting trace
synchronized either of the way
http://help.eclipse.org/luna/index.jsp?topic=%2Forg.eclipse.linuxtools.lttng.help%2Fdoc%2FTrace-synchronization.html
I have confirmed that net_dev and netif , inet* all tracepoint are enabled
. I have used ssh and scp and ping as my workloads.
But still my synchronization quality is absent . I am attaching some
screenshots.
I tried synchronization of two traces of same machine. I am getting
synchronization as absent .
Can you please tell me what can I do to debug it?
Thanks,
Divya
>
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_______________________________________________
lttng-dev mailing list
lttng-dev@lists.lttng.org
http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: Merge two LTTng CTF traces into one
[not found] ` <CA+=dQ-8oGmyKDfNEfLwu_WLeouu0XXxQVigciVBDV3T6dQJ+pg@mail.gmail.com>
@ 2015-01-06 16:28 ` Geneviève Bastien
[not found] ` <54AC0D33.80805@versatic.net>
1 sibling, 0 replies; 11+ messages in thread
From: Geneviève Bastien @ 2015-01-06 16:28 UTC (permalink / raw)
To: Divya Vyas, lttng-dev
[-- Attachment #1.1: Type: text/plain, Size: 13262 bytes --]
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@mvista.com
> <mailto:dvyas@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@mvista.com
> <mailto:dvyas@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@versatic.net <mailto:gbastien@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@versatic.net <mailto:gbastien@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@ericsson.com
>> <mailto:matthew.khouzam@ericsson.com>
>> <mailto:matthew.khouzam@ericsson.com
>> <mailto:matthew.khouzam@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@lists.lttng.org
>> <mailto:lttng-dev@lists.lttng.org>
>> <mailto:lttng-dev@lists.lttng.org
>> <mailto:lttng-dev@lists.lttng.org>>
>> >> >>
>> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
>> >> >>
>> >> >>
>> >> >>
>> >> >>
>> >> >> _______________________________________________
>> >> >> lttng-dev mailing list
>> >> >> lttng-dev@lists.lttng.org
>> <mailto:lttng-dev@lists.lttng.org>
>> <mailto:lttng-dev@lists.lttng.org
>> <mailto:lttng-dev@lists.lttng.org>>
>> >> >>
>> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
>> >> >
>> >> > _______________________________________________
>> >> > lttng-dev mailing list
>> >> > lttng-dev@lists.lttng.org
>> <mailto:lttng-dev@lists.lttng.org>
>> <mailto:lttng-dev@lists.lttng.org
>> <mailto:lttng-dev@lists.lttng.org>>
>> >> >
>> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
>> >>
>> >>
>> >> _______________________________________________
>> >> lttng-dev mailing list
>> >> lttng-dev@lists.lttng.org
>> <mailto:lttng-dev@lists.lttng.org>
>> <mailto:lttng-dev@lists.lttng.org
>> <mailto:lttng-dev@lists.lttng.org>>
>> >>
>> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
>> >>
>> >>
>>
>>
>>
>
>
>
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_______________________________________________
lttng-dev mailing list
lttng-dev@lists.lttng.org
http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: Merge two LTTng CTF traces into one
[not found] ` <54AC0D33.80805@versatic.net>
@ 2015-01-07 6:24 ` Divya Vyas
[not found] ` <CA+=dQ-_CaEvWV6uF+01tZFmfhSoHE0g=OGBKoKNC5cwMaWDSew@mail.gmail.com>
1 sibling, 0 replies; 11+ messages in thread
From: Divya Vyas @ 2015-01-07 6:24 UTC (permalink / raw)
To: Geneviève Bastien; +Cc: lttng-dev
[-- Attachment #1.1: Type: text/plain, Size: 10722 bytes --]
Hi Genevieve,
My target to is merge the traces of two different machines taken on
different time or same time .
Actually synchronization was not working on different machine so I tried on
same machine. But now I got it correctly I think so :)
For different time we need to apply offset so that their beginning matches.
I think I need to do this .
I tried applying offset on eclipse luna ( I added linux tools in install
new software) but I am not getting this option " Apply time offset ".
I tried on tracecompass also, where I am getting time offset option but the
synchronization view is empty . The window is not showing anything. The
tracecompass version is 0.1.0
Is there any other plugin for synchronization ?
On Tue, Jan 6, 2015 at 9:58 PM, Geneviève Bastien <gbastien@versatic.net>
wrote:
> 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@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@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@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@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@ericsson.com <mailto:matthew.khouzam@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@lists.lttng.org <mailto:
>>>>> lttng-dev@lists.lttng.org>
>>>>> >> >>
>>>>> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
>>>>> >> >>
>>>>> >> >>
>>>>> >> >>
>>>>> >> >>
>>>>> >> >> _______________________________________________
>>>>> >> >> lttng-dev mailing list
>>>>> >> >> lttng-dev@lists.lttng.org <mailto:lttng-dev@lists.lttng.org>
>>>>> >> >> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
>>>>> >> >
>>>>> >> > _______________________________________________
>>>>> >> > lttng-dev mailing list
>>>>> >> > lttng-dev@lists.lttng.org <mailto:lttng-dev@lists.lttng.org>
>>>>> >> > http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
>>>>> >>
>>>>> >>
>>>>> >> _______________________________________________
>>>>> >> lttng-dev mailing list
>>>>> >> lttng-dev@lists.lttng.org <mailto:lttng-dev@lists.lttng.org>
>>>>> >> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
>>>>> >>
>>>>> >>
>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>
>
>
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^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: Merge two LTTng CTF traces into one
[not found] ` <CA+=dQ-_CaEvWV6uF+01tZFmfhSoHE0g=OGBKoKNC5cwMaWDSew@mail.gmail.com>
@ 2015-01-07 14:25 ` Geneviève Bastien
[not found] ` <54AD41E8.7050604@versatic.net>
1 sibling, 0 replies; 11+ messages in thread
From: Geneviève Bastien @ 2015-01-07 14:25 UTC (permalink / raw)
To: Divya Vyas; +Cc: lttng-dev
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Hi Divya,
On 15-01-07 01:24 AM, Divya Vyas wrote:
>
> Hi Genevieve,
>
> My target to is merge the traces of two different machines taken on
> different time or same time .
Trace synchronization works by first matching events corresponding to
the sending and the reception of a TCP packet from both traces, and then
taking those matched events and computing a formula that will transform
timestamps from one trace to the same clock as another trace. So only
traces taken at the same time (meaning together, not the same clock time
of course) will work.
>
> Actually synchronization was not working on different machine so I
> tried on same machine. But now I got it correctly I think so :)
Indeed, you have the right events now, with the net_dev_queue and
netif_receive_skb. So you should be OK. But I *think* this method works
only when on a LAN. If your computers communicate through internet,
you're better off with the inet_sock_local_[in|out] method
>
> For different time we need to apply offset so that their beginning
> matches. I think I need to do this .
>
> I tried applying offset on eclipse luna ( I added linux tools in
> install new software) but I am not getting this option " Apply time
> offset ".
It is in master only so far, so you should use tracecompass to have this
option.
>
> I tried on tracecompass also, where I am getting time offset option
> but the synchronization view is empty . The window is not showing
> anything. The tracecompass version is 0.1.0
The time offset does not involve synchronization at all, it is just an
offset, so you would not see anything in the synchronization view. But
in the "Properties" view, when you select the trace, the time offset is
displayed.
Geneviève
>
> Is there any other plugin for synchronization ?
>
> On Tue, Jan 6, 2015 at 9:58 PM, Geneviève Bastien
> <gbastien@versatic.net <mailto:gbastien@versatic.net>> wrote:
>
> 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@mvista.com
>> <mailto:dvyas@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@mvista.com
>> <mailto:dvyas@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@versatic.net <mailto:gbastien@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@versatic.net
>>> <mailto:gbastien@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@ericsson.com
>>> <mailto:matthew.khouzam@ericsson.com>
>>> <mailto:matthew.khouzam@ericsson.com
>>> <mailto:matthew.khouzam@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@lists.lttng.org
>>> <mailto:lttng-dev@lists.lttng.org>
>>> <mailto:lttng-dev@lists.lttng.org
>>> <mailto:lttng-dev@lists.lttng.org>>
>>> >> >>
>>> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
>>> >> >>
>>> >> >>
>>> >> >>
>>> >> >>
>>> >> >>
>>> _______________________________________________
>>> >> >> lttng-dev mailing list
>>> >> >> lttng-dev@lists.lttng.org
>>> <mailto:lttng-dev@lists.lttng.org>
>>> <mailto:lttng-dev@lists.lttng.org
>>> <mailto:lttng-dev@lists.lttng.org>>
>>> >> >>
>>> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
>>> >> >
>>> >> >
>>> _______________________________________________
>>> >> > lttng-dev mailing list
>>> >> > lttng-dev@lists.lttng.org
>>> <mailto:lttng-dev@lists.lttng.org>
>>> <mailto:lttng-dev@lists.lttng.org
>>> <mailto:lttng-dev@lists.lttng.org>>
>>> >> >
>>> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
>>> >>
>>> >>
>>> >>
>>> _______________________________________________
>>> >> lttng-dev mailing list
>>> >> lttng-dev@lists.lttng.org
>>> <mailto:lttng-dev@lists.lttng.org>
>>> <mailto:lttng-dev@lists.lttng.org
>>> <mailto:lttng-dev@lists.lttng.org>>
>>> >>
>>> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
>>> >>
>>> >>
>>>
>>>
>>>
>>
>>
>>
>
>
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^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: Merge two LTTng CTF traces into one
[not found] ` <CA+=dQ-_u2D47dkEt_20YeGBZYBOTiADX6BWq8FR-7XWaOko10A@mail.gmail.com>
@ 2015-01-08 16:42 ` Geneviève Bastien
[not found] ` <54AEB378.8090101@versatic.net>
1 sibling, 0 replies; 11+ messages in thread
From: Geneviève Bastien @ 2015-01-08 16:42 UTC (permalink / raw)
To: Divya Vyas, lttng-dev; +Cc: François Doray
[-- Attachment #1.1: Type: text/plain, Size: 7369 bytes --]
Hi Divya,
I'm putting you back on the lttng-dev mailing list, please reply to that
list in the future so other people can answer, because I think that
trace synchronization is not exactly what you are looking for here...
> I tried the sessions at same time and communication events in between
> and it worked :)
> I am getting quality as accurate and I can see both traces merged .
Excellent!
>
> Now I come at my second point i.e taking traces from lttng sessions
> at different machines and at different time and may be communication
> events or might be not.
If the sessions are taken are different moments, they can _never_
synchronize. Trace synchronization first matches events such that one
single event from a trace (for example "sending a packet") can be
correlated to exactly one event in the second trace (the reception of
that packet). If that is the case, the first event can have a timestamp
of now and the second be timed to January 1st 1970, trace
synchronization will work and the 2 traces will have a common time
reference after synchronization.
>
> So In my opinion I need to apply time offset on one of the trace to
> match the beginning so that they can be synchronized .
>
> So like first trace timestamp starts at 07:13:59 .499 222 870 and
> other starts at 11:21:35.537 682 885 . Then I can apply timeoffset (
> How much offset ? In apply time offset advanced option If reference
> time is 7:13.... then target time will be 11:21:35... it will
> calculate the offset ) on one of the trace to match traces .
>
> Is it possible to synchronize the traces then ? Actually I tried these
> steps but not getting the synchronized traces but then both traces
> beginning is exactly same ( obviously it will as applied by the offset)
>
> Please let me know how can I synchronize the traces from different
> machines and at different time
I'm not sure what your end goal is exactly. Do you want to compare trace
executions? I am cc'ing François Doray who is currently working on a
trace comparison utility. Here's a presentation he did recently:
http://ahls.dorsal.polymtl.ca/system/files/Comparison%20of%20Traces%20to%20Diagnose%20Performance%20Variations.pdf
His work is still experimental and available on github. If that's what
you're interested in, he might give you some information on how to use it.
Otherwise, please explain what you are trying to achieve.
Geneviève
>
>
> On Thu, Jan 8, 2015 at 12:39 AM, Geneviève Bastien
> <gbastien@versatic.net <mailto:gbastien@versatic.net>> wrote:
>
> On 15-01-07 11:32 AM, Divya Vyas wrote:
>>
>> Hi ,
>>
>> I have some comments below and thanks a lot for your help
>>
>> On Jan 7, 2015 7:55 PM, "Geneviève Bastien"
>> <gbastien@versatic.net <mailto:gbastien@versatic.net>> wrote:
>> >
>> > Hi Divya,
>> >
>> >
>> > On 15-01-07 01:24 AM, Divya Vyas wrote:
>> >>
>> >>
>> >> Hi Genevieve,
>> >>
>> >> My target to is merge the traces of two different machines
>> taken on different time or same time .
>> >
>> > Trace synchronization works by first matching events
>> corresponding to the sending and the reception of a TCP packet
>> from both traces, and then taking those matched events and
>> computing a formula that will transform timestamps from one trace
>> to the same clock as another trace. So only traces taken at the
>> same time (meaning together, not the same clock time of course)
>> will work.
>>
>> I am not getting this last point , where the traces are taken
>> together. You mean that we start lttng session on two machines at
>> around same time and then during session use some communication
>> events . Then take the traces into tracecompass for
>> synchronization in experiment. I am not getting in which cases
>> time offset is needed?
>>
>
> Yes, two sessions on two machines at the same time and they
> communicate during those sessions. Then you can synchronize
> traces. The following traces are used in unit tests to test trace
> synchronization if you wish to see what it looks like:
> http://archive.eclipse.org/tracecompass/test-traces/ctf/synctraces.tar.gz
>
>> In what traces I need to apply time offset so that their
>> beginning matches. Is it applicable on the above case which I am
>> thinking above.
>>
>
> You never _need_ to apply time offset. It is if you have traces
> that do not contain communication events, and you want one of them
> to be offsetted by a certain time. For example, you have a trace
> taken GST-5 and one at GST, you cannot synchronize them because
> they don't have communication events but you want to analyze them
> with the same time reference, you would offset the one at GST-5 by
> +5 hours.
>
> Or if you have a custom event that you know happened at the same
> time on both traces, but synchronization does not support that
> event, then you can offset one trace so that both events from both
> traces have the same timestamp.
>
> Time offsetting is a manual process by the user, while trace
> synchronization is an automatic analysis using pre-defined events
> to compute a formula to transform timestamps from one trace to the
> same clock as the other.
>
>> >
>> >
>> >>
>> >> Actually synchronization was not working on different machine
>> so I tried on same machine. But now I got it correctly I think so :)
>> >
>> > Indeed, you have the right events now, with the net_dev_queue
>> and netif_receive_skb. So you should be OK. But I *think* this
>> method works only when on a LAN. If your computers communicate
>> through internet, you're better off with the
>> inet_sock_local_[in|out] method
>>
>> They are connected through LAN only.
>>
>> >
>> >>
>> >> For different time we need to apply offset so that their
>> beginning matches. I think I need to do this .
>> >>
>> >> I tried applying offset on eclipse luna ( I added linux tools
>> in install new software) but I am not getting this option "
>> Apply time offset ".
>> >
>> > It is in master only so far, so you should use tracecompass to
>> have this option.
>> >
>> >>
>> >> I tried on tracecompass also, where I am getting time offset
>> option but the synchronization view is empty . The window is not
>> showing anything. The tracecompass version is 0.1.0
>> >
>> > The time offset does not involve synchronization at all, it is
>> just an offset, so you would not see anything in the
>> synchronization view. But in the "Properties" view, when you
>> select the trace, the time offset is displayed.
>>
>> I meant to say that I tried synchronizing the traces in
>> tracecompass without time offset . The synchronizing view is empty.
>> It should show at least quality absent etc.
>>
>
> Quality absent would show only if the traces are from different
> machines. If you are trying to synchronize traces from the same
> machine, that view will stay empty.
>
> Geneviève
>
>
>
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^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: Merge two LTTng CTF traces into one
[not found] ` <54AEB378.8090101@versatic.net>
@ 2015-01-08 17:28 ` Divya Vyas
[not found] ` <CA+=dQ-_DGAtobYX8W=mQUyJMPD8LD4b6FQDrnC9SqmQr_0gWAA@mail.gmail.com>
1 sibling, 0 replies; 11+ messages in thread
From: Divya Vyas @ 2015-01-08 17:28 UTC (permalink / raw)
To: Geneviève Bastien; +Cc: lttng-dev, François Doray
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On Jan 8, 2015 10:12 PM, "Geneviève Bastien" <gbastien@versatic.net> wrote:
>
> Hi Divya,
>
> I'm putting you back on the lttng-dev mailing list, please reply to that
list in the future so other people can answer, because I think that trace
synchronization is not exactly what you are looking for here...
I am sorry I clicked reply instead of reply to all.
I have a host and on top of that I have multiple guests. Suppose like from
9 to 9:30 I want to analyze the host information as well as guest
information in single view and in a synchronized way. As the guest time is
different from host . I need the guest traces referenced at host time . and
I tracecompass I can see the host traces as well as guest traces in a
synchronized way.
I hope now I gave the clear picture of what I am doing. Please let me know
if u need some explanation.
>
>> I tried the sessions at same time and communication events in between
and it worked :)
>> I am getting quality as accurate and I can see both traces merged .
>
> Excellent!
>
>>
>> Now I come at my second point i.e taking traces from lttng sessions at
different machines and at different time and may be communication events or
might be not.
>
> If the sessions are taken are different moments, they can _never_
synchronize.
Yes I think you told that they can be analyzed by applying offset but not
synchronized.
Trace synchronization first matches events such that one single event from
a trace (for example "sending a packet") can be correlated to exactly one
event in the second trace (the reception of that packet). If that is the
case, the first event can have a timestamp of now and the second be timed
to January 1st 1970, trace synchronization will work and the 2 traces will
have a common time reference after synchronization.
What is the criteria of timestamps to be synchronized? How much two
timestamps matched for synchronization
>
>
>>
>> So In my opinion I need to apply time offset on one of the trace to
match the beginning so that they can be synchronized .
>>
>> So like first trace timestamp starts at 07:13:59 .499 222 870 and other
starts at 11:21:35.537 682 885 . Then I can apply timeoffset ( How much
offset ? In apply time offset advanced option If reference time is 7:13....
then target time will be 11:21:35... it will calculate the offset ) on one
of the trace to match traces .
>>
>> Is it possible to synchronize the traces then ? Actually I tried these
steps but not getting the synchronized traces but then both traces
beginning is exactly same ( obviously it will as applied by the offset)
>>
>> Please let me know how can I synchronize the traces from different
machines and at different time
>
> I'm not sure what your end goal is exactly. Do you want to compare trace
executions? I am cc'ing François Doray who is currently working on a trace
comparison utility. Here's a presentation he did recently:
http://ahls.dorsal.polymtl.ca/system/files/Comparison%20of%20Traces%20to%20Diagnose%20Performance%20Variations.pdf
>
> His work is still experimental and available on github. If that's what
you're interested in, he might give you some information on how to use it.
>
> Otherwise, please explain what you are trying to achieve.
>
> Geneviève
>
>
>
>>
>>
>>
>> On Thu, Jan 8, 2015 at 12:39 AM, Geneviève Bastien <gbastien@versatic.net>
wrote:
>>>
>>> On 15-01-07 11:32 AM, Divya Vyas wrote:
>>>>
>>>> Hi ,
>>>>
>>>> I have some comments below and thanks a lot for your help
>>>>
>>>> On Jan 7, 2015 7:55 PM, "Geneviève Bastien" <gbastien@versatic.net>
wrote:
>>>> >
>>>> > Hi Divya,
>>>> >
>>>> >
>>>> > On 15-01-07 01:24 AM, Divya Vyas wrote:
>>>> >>
>>>> >>
>>>> >> Hi Genevieve,
>>>> >>
>>>> >> My target to is merge the traces of two different machines taken on
different time or same time .
>>>> >
>>>> > Trace synchronization works by first matching events corresponding
to the sending and the reception of a TCP packet from both traces, and then
taking those matched events and computing a formula that will transform
timestamps from one trace to the same clock as another trace. So only
traces taken at the same time (meaning together, not the same clock time of
course) will work.
>>>>
>>>> I am not getting this last point , where the traces are taken
together. You mean that we start lttng session on two machines at around
same time and then during session use some communication events . Then
take the traces into tracecompass for synchronization in experiment. I am
not getting in which cases time offset is needed?
>>>
>>>
>>> Yes, two sessions on two machines at the same time and they communicate
during those sessions. Then you can synchronize traces. The following
traces are used in unit tests to test trace synchronization if you wish to
see what it looks like:
http://archive.eclipse.org/tracecompass/test-traces/ctf/synctraces.tar.gz
>>>
>>>> In what traces I need to apply time offset so that their beginning
matches. Is it applicable on the above case which I am thinking above.
>>>
>>>
>>> You never _need_ to apply time offset. It is if you have traces that do
not contain communication events, and you want one of them to be offsetted
by a certain time. For example, you have a trace taken GST-5 and one at
GST, you cannot synchronize them because they don't have communication
events but you want to analyze them with the same time reference, you would
offset the one at GST-5 by +5 hours.
>>>
>>> Or if you have a custom event that you know happened at the same time
on both traces, but synchronization does not support that event, then you
can offset one trace so that both events from both traces have the same
timestamp.
>>>
>>> Time offsetting is a manual process by the user, while trace
synchronization is an automatic analysis using pre-defined events to
compute a formula to transform timestamps from one trace to the same clock
as the other.
>>>
>>>> >
>>>> >
>>>> >>
>>>> >> Actually synchronization was not working on different machine so I
tried on same machine. But now I got it correctly I think so :)
>>>> >
>>>> > Indeed, you have the right events now, with the net_dev_queue and
netif_receive_skb. So you should be OK. But I *think* this method works
only when on a LAN. If your computers communicate through internet, you're
better off with the inet_sock_local_[in|out] method
>>>>
>>>> They are connected through LAN only.
>>>>
>>>> >
>>>> >>
>>>> >> For different time we need to apply offset so that their beginning
matches. I think I need to do this .
>>>> >>
>>>> >> I tried applying offset on eclipse luna ( I added linux tools in
install new software) but I am not getting this option " Apply time
offset ".
>>>> >
>>>> > It is in master only so far, so you should use tracecompass to have
this option.
>>>> >
>>>> >>
>>>> >> I tried on tracecompass also, where I am getting time offset option
but the synchronization view is empty . The window is not showing anything.
The tracecompass version is 0.1.0
>>>> >
>>>> > The time offset does not involve synchronization at all, it is just
an offset, so you would not see anything in the synchronization view. But
in the "Properties" view, when you select the trace, the time offset is
displayed.
>>>>
>>>> I meant to say that I tried synchronizing the traces in tracecompass
without time offset . The synchronizing view is empty.
>>>> It should show at least quality absent etc.
>>>
>>>
>>> Quality absent would show only if the traces are from different
machines. If you are trying to synchronize traces from the same machine,
that view will stay empty.
>>>
>>> Geneviève
>>>
>>>
>>
>
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^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: Merge two LTTng CTF traces into one
[not found] ` <CA+=dQ-_DGAtobYX8W=mQUyJMPD8LD4b6FQDrnC9SqmQr_0gWAA@mail.gmail.com>
@ 2015-01-09 17:08 ` Geneviève Bastien
0 siblings, 0 replies; 11+ messages in thread
From: Geneviève Bastien @ 2015-01-09 17:08 UTC (permalink / raw)
To: Divya Vyas; +Cc: lttng-dev
[-- Attachment #1.1: Type: text/plain, Size: 10104 bytes --]
On 01/08/2015 12:28 PM, Divya Vyas wrote:
>
>
> On Jan 8, 2015 10:12 PM, "Geneviève Bastien" <gbastien@versatic.net
> <mailto:gbastien@versatic.net>> wrote:
> >
> > Hi Divya,
> >
> > I'm putting you back on the lttng-dev mailing list, please reply to
> that list in the future so other people can answer, because I think
> that trace synchronization is not exactly what you are looking for here...
>
> I am sorry I clicked reply instead of reply to all.
>
> I have a host and on top of that I have multiple guests. Suppose like
> from 9 to 9:30 I want to analyze the host information as well as guest
> information in single view and in a synchronized way. As the guest
> time is different from host . I need the guest traces referenced at
> host time . and I tracecompass I can see the host traces as well as
> guest traces in a synchronized way.
>
Then your traces are taken at the same time. The ideal in your case is
to have your machines communicate, at least a few TCP packets during the
duration of the trace so they can be synchronized. If you trace a
virtual machine guest and host for 30 minutes, chances are the time
drift between the clocks is important so simple time offsetting at a
point that you know (either the beginnings of the trace or a precise
point in the trace) will correlate justly the traces at this point but
the further you go from there, the less accurate the time will be. Trace
synchronization accounts for the time drift so if you have accurate
synchronization, then the same accuracy applies to the whole trace.
Also, I may point you to a recently contributed Virtual Machine
Analysis. Part of it is in master, some still on gerrit (the view for
instance). The documentation is still unexistent. It works with the
Qemu/KVM virtualizer, and needs some custom compilation of lttng-modules
on both guest and host. It is still experimental. It allows to associate
a host process with a guest CPU so that you can see on the guest whether
the CPU was actually running or preempted on the host. If you're using
Qemu/KVM and are interested in this analysis, I can work on the
documentation sooner than later.
> I hope now I gave the clear picture of what I am doing. Please let me
> know if u need some explanation.
> >
> >> I tried the sessions at same time and communication events in
> between and it worked :)
> >> I am getting quality as accurate and I can see both traces merged .
> >
> > Excellent!
> >
> >>
> >> Now I come at my second point i.e taking traces from lttng
> sessions at different machines and at different time and may be
> communication events or might be not.
> >
> > If the sessions are taken are different moments, they can _never_
> synchronize.
>
> Yes I think you told that they can be analyzed by applying offset but
> not synchronized.
>
> Trace synchronization first matches events such that one single event
> from a trace (for example "sending a packet") can be correlated to
> exactly one event in the second trace (the reception of that packet).
> If that is the case, the first event can have a timestamp of now and
> the second be timed to January 1st 1970, trace synchronization will
> work and the 2 traces will have a common time reference after
> synchronization.
>
> What is the criteria of timestamps to be synchronized? How much two
> timestamps matched for synchronization
>
There is no criteria for the timestamp. Matching events is the important
part of the process. If you are interested in trace synchronization, I
invite you to read this article by Masoume Jabbarifar [1]. It is at the
base of what is implemented in Trace Compass.
[1] http://link.springer.com/article/10.1007/s10922-014-9331-7#page-1
Geneviève
> >
> >
> >>
> >> So In my opinion I need to apply time offset on one of the trace to
> match the beginning so that they can be synchronized .
> >>
> >> So like first trace timestamp starts at 07:13:59 .499 222 870 and
> other starts at 11:21:35.537 682 885 . Then I can apply timeoffset (
> How much offset ? In apply time offset advanced option If reference
> time is 7:13.... then target time will be 11:21:35... it will
> calculate the offset ) on one of the trace to match traces .
> >>
> >> Is it possible to synchronize the traces then ? Actually I tried
> these steps but not getting the synchronized traces but then both
> traces beginning is exactly same ( obviously it will as applied by the
> offset)
> >>
> >> Please let me know how can I synchronize the traces from different
> machines and at different time
> >
> > I'm not sure what your end goal is exactly. Do you want to compare
> trace executions? I am cc'ing François Doray who is currently working
> on a trace comparison utility. Here's a presentation he did recently:
> http://ahls.dorsal.polymtl.ca/system/files/Comparison%20of%20Traces%20to%20Diagnose%20Performance%20Variations.pdf
> >
> > His work is still experimental and available on github. If that's
> what you're interested in, he might give you some information on how
> to use it.
> >
> > Otherwise, please explain what you are trying to achieve.
> >
> > Geneviève
> >
> >
> >
> >>
> >>
> >>
> >> On Thu, Jan 8, 2015 at 12:39 AM, Geneviève Bastien
> <gbastien@versatic.net <mailto:gbastien@versatic.net>> wrote:
> >>>
> >>> On 15-01-07 11:32 AM, Divya Vyas wrote:
> >>>>
> >>>> Hi ,
> >>>>
> >>>> I have some comments below and thanks a lot for your help
> >>>>
> >>>> On Jan 7, 2015 7:55 PM, "Geneviève Bastien"
> <gbastien@versatic.net <mailto:gbastien@versatic.net>> wrote:
> >>>> >
> >>>> > Hi Divya,
> >>>> >
> >>>> >
> >>>> > On 15-01-07 01:24 AM, Divya Vyas wrote:
> >>>> >>
> >>>> >>
> >>>> >> Hi Genevieve,
> >>>> >>
> >>>> >> My target to is merge the traces of two different machines
> taken on different time or same time .
> >>>> >
> >>>> > Trace synchronization works by first matching events
> corresponding to the sending and the reception of a TCP packet from
> both traces, and then taking those matched events and computing a
> formula that will transform timestamps from one trace to the same
> clock as another trace. So only traces taken at the same time (meaning
> together, not the same clock time of course) will work.
> >>>>
> >>>> I am not getting this last point , where the traces are taken
> together. You mean that we start lttng session on two machines at
> around same time and then during session use some communication
> events . Then take the traces into tracecompass for synchronization in
> experiment. I am not getting in which cases time offset is needed?
> >>>
> >>>
> >>> Yes, two sessions on two machines at the same time and they
> communicate during those sessions. Then you can synchronize traces.
> The following traces are used in unit tests to test trace
> synchronization if you wish to see what it looks like:
> http://archive.eclipse.org/tracecompass/test-traces/ctf/synctraces.tar.gz
> >>>
> >>>> In what traces I need to apply time offset so that their
> beginning matches. Is it applicable on the above case which I am
> thinking above.
> >>>
> >>>
> >>> You never _need_ to apply time offset. It is if you have traces
> that do not contain communication events, and you want one of them to
> be offsetted by a certain time. For example, you have a trace taken
> GST-5 and one at GST, you cannot synchronize them because they don't
> have communication events but you want to analyze them with the same
> time reference, you would offset the one at GST-5 by +5 hours.
> >>>
> >>> Or if you have a custom event that you know happened at the same
> time on both traces, but synchronization does not support that event,
> then you can offset one trace so that both events from both traces
> have the same timestamp.
> >>>
> >>> Time offsetting is a manual process by the user, while trace
> synchronization is an automatic analysis using pre-defined events to
> compute a formula to transform timestamps from one trace to the same
> clock as the other.
> >>>
> >>>> >
> >>>> >
> >>>> >>
> >>>> >> Actually synchronization was not working on different machine
> so I tried on same machine. But now I got it correctly I think so :)
> >>>> >
> >>>> > Indeed, you have the right events now, with the net_dev_queue
> and netif_receive_skb. So you should be OK. But I *think* this method
> works only when on a LAN. If your computers communicate through
> internet, you're better off with the inet_sock_local_[in|out] method
> >>>>
> >>>> They are connected through LAN only.
> >>>>
> >>>> >
> >>>> >>
> >>>> >> For different time we need to apply offset so that their
> beginning matches. I think I need to do this .
> >>>> >>
> >>>> >> I tried applying offset on eclipse luna ( I added linux tools
> in install new software) but I am not getting this option " Apply
> time offset ".
> >>>> >
> >>>> > It is in master only so far, so you should use tracecompass to
> have this option.
> >>>> >
> >>>> >>
> >>>> >> I tried on tracecompass also, where I am getting time offset
> option but the synchronization view is empty . The window is not
> showing anything. The tracecompass version is 0.1.0
> >>>> >
> >>>> > The time offset does not involve synchronization at all, it is
> just an offset, so you would not see anything in the synchronization
> view. But in the "Properties" view, when you select the trace, the
> time offset is displayed.
> >>>>
> >>>> I meant to say that I tried synchronizing the traces in
> tracecompass without time offset . The synchronizing view is empty.
> >>>> It should show at least quality absent etc.
> >>>
> >>>
> >>> Quality absent would show only if the traces are from different
> machines. If you are trying to synchronize traces from the same
> machine, that view will stay empty.
> >>>
> >>> Geneviève
> >>>
> >>>
> >>
> >
>
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^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: Merge two LTTng CTF traces into one
[not found] <CA+=dQ--QY6zW4m-V-tQFP6DGFH=jsyrR6SPnhfLxq3H5LJg4HQ@mail.gmail.com>
@ 2014-12-22 13:07 ` Michel Dagenais
0 siblings, 0 replies; 11+ messages in thread
From: Michel Dagenais @ 2014-12-22 13:07 UTC (permalink / raw)
To: Divya Vyas; +Cc: lttng-dev
[-- Attachment #1.1: Type: text/plain, Size: 928 bytes --]
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.
----- Mail original -----
> 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@lists.lttng.org
> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
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^ permalink raw reply [flat|nested] 11+ messages in thread
* Merge two LTTng CTF traces into one
@ 2014-12-22 12:02 Divya Vyas
0 siblings, 0 replies; 11+ messages in thread
From: Divya Vyas @ 2014-12-22 12:02 UTC (permalink / raw)
To: lttng-dev
[-- Attachment #1.1: Type: text/plain, Size: 182 bytes --]
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
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2014-12-22 15:17 ` Merge two LTTng CTF traces into one Matthew Khouzam
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2014-12-22 17:54 ` Matthew Khouzam
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2015-01-05 7:33 ` Fwd: " Divya Vyas
[not found] ` <54AAB14E.70004@versatic.net>
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2015-01-06 16:28 ` Geneviève Bastien
[not found] ` <54AC0D33.80805@versatic.net>
2015-01-07 6:24 ` Divya Vyas
[not found] ` <CA+=dQ-_CaEvWV6uF+01tZFmfhSoHE0g=OGBKoKNC5cwMaWDSew@mail.gmail.com>
2015-01-07 14:25 ` Geneviève Bastien
[not found] ` <54AD41E8.7050604@versatic.net>
[not found] ` <CA+=dQ--GJj1rt4jTFOc-sV4YMNb+jpWXnWT_7oULab-FiXRJaQ@mail.gmail.com>
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[not found] ` <CA+=dQ-_u2D47dkEt_20YeGBZYBOTiADX6BWq8FR-7XWaOko10A@mail.gmail.com>
2015-01-08 16:42 ` Geneviève Bastien
[not found] ` <54AEB378.8090101@versatic.net>
2015-01-08 17:28 ` Divya Vyas
[not found] ` <CA+=dQ-_DGAtobYX8W=mQUyJMPD8LD4b6FQDrnC9SqmQr_0gWAA@mail.gmail.com>
2015-01-09 17:08 ` Geneviève Bastien
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2014-12-22 13:07 ` Michel Dagenais
2014-12-22 12:02 Divya Vyas
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