I'm probably missing something, is there supposed to be a [6] with your ceph changes? -Sam On Fri, Aug 1, 2014 at 1:17 PM, Samuel Just <sam.just@xxxxxxxxxxx> wrote: > Reading! > -Sam > > On Fri, Aug 1, 2014 at 9:28 AM, Marios-Evaggelos Kogias > <marioskogias@xxxxxxxxx> wrote: >> Hello all, >> >> my name is Marios Kogias and I am a student at the National Technical >> University of Athens. As part of my diploma thesis and my participation in >> Google Summer of Code 2014 (in the LTTng organization) I am working on a >> low-overhead tracing infrastructure for distributed systems. I am also >> collaborating with the Synnefo team (https://www.synnefo.org/) and especially >> with Vangelis Koukis, Constantinos Venetsanopoulos and Filippos Giannakos (cc) >> >> Some time ago, we started experimenting with RADOS instrumentation >> using LTTng and >> we noticed that there are similar endeavours in the Ceph github repository [1]. >> >> However, unlike your approach, we are following an annotation-based tracing >> schema, which enables us to track a specific request from the time it enters >> the system at higher levels till it is finally served by RADOS. >> >> In general, we try to implement the tracing semantics described in the Dapper >> paper [2] in order to trace the causal relationships between the different >> processing phases that an IO request may trigger. Our target is an end-to-end >> visualisation of the request's route in the system, accompanied by information >> concerning latencies in each processing phase. Thanks to LTTng this can happen >> with a minimal overhead and in realtime. In order to visualize the results we >> have integrated Twitter's Zipkin [3], (which is a tracing system >> entirely based on >> Dapper) with LTTng. >> >> You can find a proof of concept of what we've done so far here: >> >> http://snf-551656.vm.okeanos.grnet.gr:8080/traces/0b554b8a48cb3e84?serviceName=MOSDOp >> >> In the above link you can see the trace of a write request served by a RADOS >> pool with replication level set to 3 (two replicas). >> >> We'd love to have early feedback and comments from you guys too, >> so that we can incorporate useful recommendations. You can find all >> the relevant code >> here[5][6]. If you have any questions or you wish to experiment with the >> project please do not hesitate to contact us. >> >> Kind regards, >> Marios >> >> [1]https://github.com/ceph/ceph/tree/wip-lttng >> [2]http://static.googleusercontent.com/media/research.google.com/el//pubs/archive/36356.pdf >> [3]http://twitter.github.io/zipkin/ >> [4] https://github.com/marioskogias/blkin >> [5] https://github.com/marioskogias/babeltrace-plugins >> -- >> To unsubscribe from this list: send the line "unsubscribe ceph-devel" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
