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author | 2018-01-04 13:43:33 +0800 | |
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committer | 2018-01-05 11:59:39 +0800 | |
commit | 812ff6ca9fcd3e629e49d4328905f33eee8ca3f5 (patch) | |
tree | 04ece7b4da00d9d2f98093774594f4057ae561d4 /src/ceph/doc/dev/blkin.rst | |
parent | 15280273faafb77777eab341909a3f495cf248d9 (diff) |
initial code repo
This patch creates initial code repo.
For ceph, luminous stable release will be used for base code,
and next changes and optimization for ceph will be added to it.
For opensds, currently any changes can be upstreamed into original
opensds repo (https://github.com/opensds/opensds), and so stor4nfv
will directly clone opensds code to deploy stor4nfv environment.
And the scripts for deployment based on ceph and opensds will be
put into 'ci' directory.
Change-Id: I46a32218884c75dda2936337604ff03c554648e4
Signed-off-by: Qiaowei Ren <qiaowei.ren@intel.com>
Diffstat (limited to 'src/ceph/doc/dev/blkin.rst')
-rw-r--r-- | src/ceph/doc/dev/blkin.rst | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/src/ceph/doc/dev/blkin.rst b/src/ceph/doc/dev/blkin.rst new file mode 100644 index 0000000..8e0320f --- /dev/null +++ b/src/ceph/doc/dev/blkin.rst @@ -0,0 +1,167 @@ +========================= + Tracing Ceph With BlkKin +========================= + +Ceph can use Blkin, a library created by Marios Kogias and others, +which enables tracking a specific request from the time it enters +the system at higher levels till it is finally served by RADOS. + +In general, Blkin implements the Dapper_ tracing semantics +in order to show the causal relationships between the different +processing phases that an IO request may trigger. The goal 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. The LTTng traces can then be visualized with Twitter's +Zipkin_. + +.. _Dapper: http://static.googleusercontent.com/media/research.google.com/el//pubs/archive/36356.pdf +.. _Zipkin: http://zipkin.io/ + + +Installing Blkin +================ + +You can install Markos Kogias' upstream Blkin_ by hand.:: + + cd blkin/ + make && make install + +or build distribution packages using DistroReadyBlkin_, which also comes with +pkgconfig support. If you choose the latter, then you must generate the +configure and make files first.:: + + cd blkin + autoreconf -i + +.. _Blkin: https://github.com/marioskogias/blkin +.. _DistroReadyBlkin: https://github.com/agshew/blkin + + +Configuring Ceph with Blkin +=========================== + +If you built and installed Blkin by hand, rather than building and +installing packages, then set these variables before configuring +Ceph.:: + + export BLKIN_CFLAGS=-Iblkin/ + export BLKIN_LIBS=-lzipkin-cpp + +Since there are separate lttng and blkin changes to Ceph, you may +want to configure with something like:: + + ./configure --with-blkin --without-lttng --with-debug + + +Testing Blkin +============= + +It's easy to test Ceph's Blkin tracing. Let's assume you don't have +Ceph already running, and you compiled Ceph with Blkin support but +you did't install it. Then launch Ceph with the ``vstart.sh`` script +in Ceph's src directgory so you can see the possible tracepoints.:: + + cd src + OSD=3 MON=3 RGW=1 ./vstart.sh -n + lttng list --userspace + +You'll see something like the following::: + + UST events: + ------------- + PID: 8987 - Name: ./ceph-osd + zipkin:timestamp (loglevel: TRACE_WARNING (4)) (type: tracepoint) + zipkin:keyval (loglevel: TRACE_WARNING (4)) (type: tracepoint) + ust_baddr_statedump:soinfo (loglevel: TRACE_DEBUG_LINE (13)) (type: tracepoint) + + PID: 8407 - Name: ./ceph-mon + zipkin:timestamp (loglevel: TRACE_WARNING (4)) (type: tracepoint) + zipkin:keyval (loglevel: TRACE_WARNING (4)) (type: tracepoint) + ust_baddr_statedump:soinfo (loglevel: TRACE_DEBUG_LINE (13)) (type: tracepoint) + + ... + +Next, stop Ceph so that the tracepoints can be enabled.:: + + ./stop.sh + +Start up an LTTng session and enable the tracepoints.:: + + lttng create blkin-test + lttng enable-event --userspace zipkin:timestamp + lttng enable-event --userspace zipkin:keyval + lttng start + +Then start up Ceph again.:: + + OSD=3 MON=3 RGW=1 ./vstart.sh -n + +You may want to check that ceph is up.:: + + ./ceph status + +Now put something in usin rados, check that it made it, get it back, and remove it.:: + + ./rados mkpool test-blkin + ./rados put test-object-1 ./vstart.sh --pool=test-blkin + ./rados -p test-blkin ls + ./ceph osd map test-blkin test-object-1 + ./rados get test-object-1 ./vstart-copy.sh --pool=test-blkin + md5sum vstart* + ./rados rm test-object-1 --pool=test-blkin + +You could also use the example in ``examples/librados/`` or ``rados bench``. + +Then stop the LTTng session and see what was collected.:: + + lttng stop + lttng view + +You'll see something like::: + + [13:09:07.755054973] (+?.?????????) scruffy zipkin:timestamp: { cpu_id = 5 }, { trace_name = "Main", service_name = "MOSDOp", port_no = 0, ip = "0.0.0.0", trace_id = 7492589359882233221, span_id = 2694140257089376129, parent_span_id = 0, event = "Message allocated" } + [13:09:07.755071569] (+0.000016596) scruffy zipkin:keyval: { cpu_id = 5 }, { trace_name = "Main", service_name = "MOSDOp", port_no = 0, ip = "0.0.0.0", trace_id = 7492589359882233221, span_id = 2694140257089376129, parent_span_id = 0, key = "Type", val = "MOSDOp" } + [13:09:07.755074217] (+0.000002648) scruffy zipkin:keyval: { cpu_id = 5 }, { trace_name = "Main", service_name = "MOSDOp", port_no = 0, ip = "0.0.0.0", trace_id = 7492589359882233221, span_id = 2694140257089376129, parent_span_id = 0, key = "Reqid", val = "client.4126.0:1" } + ... + + +Install Zipkin +=============== +One of the points of using Blkin is so that you can look at the traces +using Zipkin. Users should run Zipkin as a tracepoints collector and +also a web service, which means users need to run three services, +zipkin-collector, zipkin-query and zipkin-web. + +Download Zipkin Package:: + + wget https://github.com/twitter/zipkin/archive/1.1.0.tar.gz + tar zxf 1.1.0.tar.gz + cd zipkin-1.1.0 + bin/collector cassandra & + bin/query cassandra & + bin/web & + +Check Zipkin:: + + bin/test + Browse http://${zipkin-web-ip}:8080 + + +Show Ceph's Blkin Traces in Zipkin-web +====================================== +Blkin provides a script which translates lttng result to Zipkin +(Dapper) semantics. + +Send lttng data to Zipkin:: + + python3 babeltrace_zipkin.py ${lttng-traces-dir}/${blkin-test}/ust/uid/0/64-bit/ -p ${zipkin-collector-port(9410 by default)} -s ${zipkin-collector-ip} + +Example:: + + python3 babeltrace_zipkin.py ~/lttng-traces-dir/blkin-test-20150225-160222/ust/uid/0/64-bit/ -p 9410 -s 127.0.0.1 + +Check Ceph traces on webpage:: + + Browse http://${zipkin-web-ip}:8080 + Click "Find traces" |