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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/rados/troubleshooting/memory-profiling.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/rados/troubleshooting/memory-profiling.rst')
-rw-r--r-- | src/ceph/doc/rados/troubleshooting/memory-profiling.rst | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/src/ceph/doc/rados/troubleshooting/memory-profiling.rst b/src/ceph/doc/rados/troubleshooting/memory-profiling.rst new file mode 100644 index 0000000..e2396e2 --- /dev/null +++ b/src/ceph/doc/rados/troubleshooting/memory-profiling.rst @@ -0,0 +1,142 @@ +================== + Memory Profiling +================== + +Ceph MON, OSD and MDS can generate heap profiles using +``tcmalloc``. To generate heap profiles, ensure you have +``google-perftools`` installed:: + + sudo apt-get install google-perftools + +The profiler dumps output to your ``log file`` directory (i.e., +``/var/log/ceph``). See `Logging and Debugging`_ for details. +To view the profiler logs with Google's performance tools, execute the +following:: + + google-pprof --text {path-to-daemon} {log-path/filename} + +For example:: + + $ ceph tell osd.0 heap start_profiler + $ ceph tell osd.0 heap dump + osd.0 tcmalloc heap stats:------------------------------------------------ + MALLOC: 2632288 ( 2.5 MiB) Bytes in use by application + MALLOC: + 499712 ( 0.5 MiB) Bytes in page heap freelist + MALLOC: + 543800 ( 0.5 MiB) Bytes in central cache freelist + MALLOC: + 327680 ( 0.3 MiB) Bytes in transfer cache freelist + MALLOC: + 1239400 ( 1.2 MiB) Bytes in thread cache freelists + MALLOC: + 1142936 ( 1.1 MiB) Bytes in malloc metadata + MALLOC: ------------ + MALLOC: = 6385816 ( 6.1 MiB) Actual memory used (physical + swap) + MALLOC: + 0 ( 0.0 MiB) Bytes released to OS (aka unmapped) + MALLOC: ------------ + MALLOC: = 6385816 ( 6.1 MiB) Virtual address space used + MALLOC: + MALLOC: 231 Spans in use + MALLOC: 56 Thread heaps in use + MALLOC: 8192 Tcmalloc page size + ------------------------------------------------ + Call ReleaseFreeMemory() to release freelist memory to the OS (via madvise()). + Bytes released to the OS take up virtual address space but no physical memory. + $ google-pprof --text \ + /usr/bin/ceph-osd \ + /var/log/ceph/ceph-osd.0.profile.0001.heap + Total: 3.7 MB + 1.9 51.1% 51.1% 1.9 51.1% ceph::log::Log::create_entry + 1.8 47.3% 98.4% 1.8 47.3% std::string::_Rep::_S_create + 0.0 0.4% 98.9% 0.0 0.6% SimpleMessenger::add_accept_pipe + 0.0 0.4% 99.2% 0.0 0.6% decode_message + ... + +Another heap dump on the same daemon will add another file. It is +convenient to compare to a previous heap dump to show what has grown +in the interval. For instance:: + + $ google-pprof --text --base out/osd.0.profile.0001.heap \ + ceph-osd out/osd.0.profile.0003.heap + Total: 0.2 MB + 0.1 50.3% 50.3% 0.1 50.3% ceph::log::Log::create_entry + 0.1 46.6% 96.8% 0.1 46.6% std::string::_Rep::_S_create + 0.0 0.9% 97.7% 0.0 26.1% ReplicatedPG::do_op + 0.0 0.8% 98.5% 0.0 0.8% __gnu_cxx::new_allocator::allocate + +Refer to `Google Heap Profiler`_ for additional details. + +Once you have the heap profiler installed, start your cluster and +begin using the heap profiler. You may enable or disable the heap +profiler at runtime, or ensure that it runs continuously. For the +following commandline usage, replace ``{daemon-type}`` with ``mon``, +``osd`` or ``mds``, and replace ``{daemon-id}`` with the OSD number or +the MON or MDS id. + + +Starting the Profiler +--------------------- + +To start the heap profiler, execute the following:: + + ceph tell {daemon-type}.{daemon-id} heap start_profiler + +For example:: + + ceph tell osd.1 heap start_profiler + +Alternatively the profile can be started when the daemon starts +running if the ``CEPH_HEAP_PROFILER_INIT=true`` variable is found in +the environment. + +Printing Stats +-------------- + +To print out statistics, execute the following:: + + ceph tell {daemon-type}.{daemon-id} heap stats + +For example:: + + ceph tell osd.0 heap stats + +.. note:: Printing stats does not require the profiler to be running and does + not dump the heap allocation information to a file. + + +Dumping Heap Information +------------------------ + +To dump heap information, execute the following:: + + ceph tell {daemon-type}.{daemon-id} heap dump + +For example:: + + ceph tell mds.a heap dump + +.. note:: Dumping heap information only works when the profiler is running. + + +Releasing Memory +---------------- + +To release memory that ``tcmalloc`` has allocated but which is not being used by +the Ceph daemon itself, execute the following:: + + ceph tell {daemon-type}{daemon-id} heap release + +For example:: + + ceph tell osd.2 heap release + + +Stopping the Profiler +--------------------- + +To stop the heap profiler, execute the following:: + + ceph tell {daemon-type}.{daemon-id} heap stop_profiler + +For example:: + + ceph tell osd.0 heap stop_profiler + +.. _Logging and Debugging: ../log-and-debug +.. _Google Heap Profiler: http://goog-perftools.sourceforge.net/doc/heap_profiler.html |