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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:45:59 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:45:59 +0000 |
commit | 19fcec84d8d7d21e796c7624e521b60d28ee21ed (patch) | |
tree | 42d26aa27d1e3f7c0b8bd3fd14e7d7082f5008dc /doc/rados/troubleshooting/log-and-debug.rst | |
parent | Initial commit. (diff) | |
download | ceph-19fcec84d8d7d21e796c7624e521b60d28ee21ed.tar.xz ceph-19fcec84d8d7d21e796c7624e521b60d28ee21ed.zip |
Adding upstream version 16.2.11+ds.upstream/16.2.11+dsupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'doc/rados/troubleshooting/log-and-debug.rst')
-rw-r--r-- | doc/rados/troubleshooting/log-and-debug.rst | 599 |
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diff --git a/doc/rados/troubleshooting/log-and-debug.rst b/doc/rados/troubleshooting/log-and-debug.rst new file mode 100644 index 000000000..71170149b --- /dev/null +++ b/doc/rados/troubleshooting/log-and-debug.rst @@ -0,0 +1,599 @@ +======================= + Logging and Debugging +======================= + +Typically, when you add debugging to your Ceph configuration, you do so at +runtime. You can also add Ceph debug logging to your Ceph configuration file if +you are encountering issues when starting your cluster. You may view Ceph log +files under ``/var/log/ceph`` (the default location). + +.. tip:: When debug output slows down your system, the latency can hide + race conditions. + +Logging is resource intensive. If you are encountering a problem in a specific +area of your cluster, enable logging for that area of the cluster. For example, +if your OSDs are running fine, but your metadata servers are not, you should +start by enabling debug logging for the specific metadata server instance(s) +giving you trouble. Enable logging for each subsystem as needed. + +.. important:: Verbose logging can generate over 1GB of data per hour. If your + OS disk reaches its capacity, the node will stop working. + +If you enable or increase the rate of Ceph logging, ensure that you have +sufficient disk space on your OS disk. See `Accelerating Log Rotation`_ for +details on rotating log files. When your system is running well, remove +unnecessary debugging settings to ensure your cluster runs optimally. Logging +debug output messages is relatively slow, and a waste of resources when +operating your cluster. + +See `Subsystem, Log and Debug Settings`_ for details on available settings. + +Runtime +======= + +If you would like to see the configuration settings at runtime, you must log +in to a host with a running daemon and execute the following:: + + ceph daemon {daemon-name} config show | less + +For example,:: + + ceph daemon osd.0 config show | less + +To activate Ceph's debugging output (*i.e.*, ``dout()``) at runtime, use the +``ceph tell`` command to inject arguments into the runtime configuration:: + + ceph tell {daemon-type}.{daemon id or *} config set {name} {value} + +Replace ``{daemon-type}`` with one of ``osd``, ``mon`` or ``mds``. You may apply +the runtime setting to all daemons of a particular type with ``*``, or specify +a specific daemon's ID. For example, to increase +debug logging for a ``ceph-osd`` daemon named ``osd.0``, execute the following:: + + ceph tell osd.0 config set debug_osd 0/5 + +The ``ceph tell`` command goes through the monitors. If you cannot bind to the +monitor, you can still make the change by logging into the host of the daemon +whose configuration you'd like to change using ``ceph daemon``. +For example:: + + sudo ceph daemon osd.0 config set debug_osd 0/5 + +See `Subsystem, Log and Debug Settings`_ for details on available settings. + + +Boot Time +========= + +To activate Ceph's debugging output (*i.e.*, ``dout()``) at boot time, you must +add settings to your Ceph configuration file. Subsystems common to each daemon +may be set under ``[global]`` in your configuration file. Subsystems for +particular daemons are set under the daemon section in your configuration file +(*e.g.*, ``[mon]``, ``[osd]``, ``[mds]``). For example:: + + [global] + debug ms = 1/5 + + [mon] + debug mon = 20 + debug paxos = 1/5 + debug auth = 2 + + [osd] + debug osd = 1/5 + debug filestore = 1/5 + debug journal = 1 + debug monc = 5/20 + + [mds] + debug mds = 1 + debug mds balancer = 1 + + +See `Subsystem, Log and Debug Settings`_ for details. + + +Accelerating Log Rotation +========================= + +If your OS disk is relatively full, you can accelerate log rotation by modifying +the Ceph log rotation file at ``/etc/logrotate.d/ceph``. Add a size setting +after the rotation frequency to accelerate log rotation (via cronjob) if your +logs exceed the size setting. For example, the default setting looks like +this:: + + rotate 7 + weekly + compress + sharedscripts + +Modify it by adding a ``size`` setting. :: + + rotate 7 + weekly + size 500M + compress + sharedscripts + +Then, start the crontab editor for your user space. :: + + crontab -e + +Finally, add an entry to check the ``etc/logrotate.d/ceph`` file. :: + + 30 * * * * /usr/sbin/logrotate /etc/logrotate.d/ceph >/dev/null 2>&1 + +The preceding example checks the ``etc/logrotate.d/ceph`` file every 30 minutes. + + +Valgrind +======== + +Debugging may also require you to track down memory and threading issues. +You can run a single daemon, a type of daemon, or the whole cluster with +Valgrind. You should only use Valgrind when developing or debugging Ceph. +Valgrind is computationally expensive, and will slow down your system otherwise. +Valgrind messages are logged to ``stderr``. + + +Subsystem, Log and Debug Settings +================================= + +In most cases, you will enable debug logging output via subsystems. + +Ceph Subsystems +--------------- + +Each subsystem has a logging level for its output logs, and for its logs +in-memory. You may set different values for each of these subsystems by setting +a log file level and a memory level for debug logging. Ceph's logging levels +operate on a scale of ``1`` to ``20``, where ``1`` is terse and ``20`` is +verbose [#]_ . In general, the logs in-memory are not sent to the output log unless: + +- a fatal signal is raised or +- an ``assert`` in source code is triggered or +- upon requested. Please consult `document on admin socket <http://docs.ceph.com/en/latest/man/8/ceph/#daemon>`_ for more details. + +A debug logging setting can take a single value for the log level and the +memory level, which sets them both as the same value. For example, if you +specify ``debug ms = 5``, Ceph will treat it as a log level and a memory level +of ``5``. You may also specify them separately. The first setting is the log +level, and the second setting is the memory level. You must separate them with +a forward slash (/). For example, if you want to set the ``ms`` subsystem's +debug logging level to ``1`` and its memory level to ``5``, you would specify it +as ``debug ms = 1/5``. For example: + + + +.. code-block:: ini + + debug {subsystem} = {log-level}/{memory-level} + #for example + debug mds balancer = 1/20 + + +The following table provides a list of Ceph subsystems and their default log and +memory levels. Once you complete your logging efforts, restore the subsystems +to their default level or to a level suitable for normal operations. + + ++--------------------+-----------+--------------+ +| Subsystem | Log Level | Memory Level | ++====================+===========+==============+ +| ``default`` | 0 | 5 | ++--------------------+-----------+--------------+ +| ``lockdep`` | 0 | 1 | ++--------------------+-----------+--------------+ +| ``context`` | 0 | 1 | ++--------------------+-----------+--------------+ +| ``crush`` | 1 | 1 | ++--------------------+-----------+--------------+ +| ``mds`` | 1 | 5 | ++--------------------+-----------+--------------+ +| ``mds balancer`` | 1 | 5 | ++--------------------+-----------+--------------+ +| ``mds locker`` | 1 | 5 | ++--------------------+-----------+--------------+ +| ``mds log`` | 1 | 5 | ++--------------------+-----------+--------------+ +| ``mds log expire`` | 1 | 5 | ++--------------------+-----------+--------------+ +| ``mds migrator`` | 1 | 5 | ++--------------------+-----------+--------------+ +| ``buffer`` | 0 | 1 | ++--------------------+-----------+--------------+ +| ``timer`` | 0 | 1 | ++--------------------+-----------+--------------+ +| ``filer`` | 0 | 1 | ++--------------------+-----------+--------------+ +| ``striper`` | 0 | 1 | ++--------------------+-----------+--------------+ +| ``objecter`` | 0 | 1 | ++--------------------+-----------+--------------+ +| ``rados`` | 0 | 5 | ++--------------------+-----------+--------------+ +| ``rbd`` | 0 | 5 | ++--------------------+-----------+--------------+ +| ``rbd mirror`` | 0 | 5 | ++--------------------+-----------+--------------+ +| ``rbd replay`` | 0 | 5 | ++--------------------+-----------+--------------+ +| ``journaler`` | 0 | 5 | ++--------------------+-----------+--------------+ +| ``objectcacher`` | 0 | 5 | ++--------------------+-----------+--------------+ +| ``client`` | 0 | 5 | ++--------------------+-----------+--------------+ +| ``osd`` | 1 | 5 | ++--------------------+-----------+--------------+ +| ``optracker`` | 0 | 5 | ++--------------------+-----------+--------------+ +| ``objclass`` | 0 | 5 | ++--------------------+-----------+--------------+ +| ``filestore`` | 1 | 3 | ++--------------------+-----------+--------------+ +| ``journal`` | 1 | 3 | ++--------------------+-----------+--------------+ +| ``ms`` | 0 | 5 | ++--------------------+-----------+--------------+ +| ``mon`` | 1 | 5 | ++--------------------+-----------+--------------+ +| ``monc`` | 0 | 10 | ++--------------------+-----------+--------------+ +| ``paxos`` | 1 | 5 | ++--------------------+-----------+--------------+ +| ``tp`` | 0 | 5 | ++--------------------+-----------+--------------+ +| ``auth`` | 1 | 5 | ++--------------------+-----------+--------------+ +| ``crypto`` | 1 | 5 | ++--------------------+-----------+--------------+ +| ``finisher`` | 1 | 1 | ++--------------------+-----------+--------------+ +| ``reserver`` | 1 | 1 | ++--------------------+-----------+--------------+ +| ``heartbeatmap`` | 1 | 5 | ++--------------------+-----------+--------------+ +| ``perfcounter`` | 1 | 5 | ++--------------------+-----------+--------------+ +| ``rgw`` | 1 | 5 | ++--------------------+-----------+--------------+ +| ``rgw sync`` | 1 | 5 | ++--------------------+-----------+--------------+ +| ``civetweb`` | 1 | 10 | ++--------------------+-----------+--------------+ +| ``javaclient`` | 1 | 5 | ++--------------------+-----------+--------------+ +| ``asok`` | 1 | 5 | ++--------------------+-----------+--------------+ +| ``throttle`` | 1 | 1 | ++--------------------+-----------+--------------+ +| ``refs`` | 0 | 0 | ++--------------------+-----------+--------------+ +| ``compressor`` | 1 | 5 | ++--------------------+-----------+--------------+ +| ``bluestore`` | 1 | 5 | ++--------------------+-----------+--------------+ +| ``bluefs`` | 1 | 5 | ++--------------------+-----------+--------------+ +| ``bdev`` | 1 | 3 | ++--------------------+-----------+--------------+ +| ``kstore`` | 1 | 5 | ++--------------------+-----------+--------------+ +| ``rocksdb`` | 4 | 5 | ++--------------------+-----------+--------------+ +| ``leveldb`` | 4 | 5 | ++--------------------+-----------+--------------+ +| ``memdb`` | 4 | 5 | ++--------------------+-----------+--------------+ +| ``fuse`` | 1 | 5 | ++--------------------+-----------+--------------+ +| ``mgr`` | 1 | 5 | ++--------------------+-----------+--------------+ +| ``mgrc`` | 1 | 5 | ++--------------------+-----------+--------------+ +| ``dpdk`` | 1 | 5 | ++--------------------+-----------+--------------+ +| ``eventtrace`` | 1 | 5 | ++--------------------+-----------+--------------+ + + +Logging Settings +---------------- + +Logging and debugging settings are not required in a Ceph configuration file, +but you may override default settings as needed. Ceph supports the following +settings: + + +``log file`` + +:Description: The location of the logging file for your cluster. +:Type: String +:Required: No +:Default: ``/var/log/ceph/$cluster-$name.log`` + + +``log max new`` + +:Description: The maximum number of new log files. +:Type: Integer +:Required: No +:Default: ``1000`` + + +``log max recent`` + +:Description: The maximum number of recent events to include in a log file. +:Type: Integer +:Required: No +:Default: ``10000`` + + +``log to file`` + +:Description: Determines if logging messages should appear in a file. +:Type: Boolean +:Required: No +:Default: ``true`` + + +``log to stderr`` + +:Description: Determines if logging messages should appear in ``stderr``. +:Type: Boolean +:Required: No +:Default: ``false`` + + +``err to stderr`` + +:Description: Determines if error messages should appear in ``stderr``. +:Type: Boolean +:Required: No +:Default: ``true`` + + +``log to syslog`` + +:Description: Determines if logging messages should appear in ``syslog``. +:Type: Boolean +:Required: No +:Default: ``false`` + + +``err to syslog`` + +:Description: Determines if error messages should appear in ``syslog``. +:Type: Boolean +:Required: No +:Default: ``false`` + + +``log flush on exit`` + +:Description: Determines if Ceph should flush the log files after exit. +:Type: Boolean +:Required: No +:Default: ``false`` + + +``clog to monitors`` + +:Description: Determines if ``clog`` messages should be sent to monitors. +:Type: Boolean +:Required: No +:Default: ``true`` + + +``clog to syslog`` + +:Description: Determines if ``clog`` messages should be sent to syslog. +:Type: Boolean +:Required: No +:Default: ``false`` + + +``mon cluster log to syslog`` + +:Description: Determines if the cluster log should be output to the syslog. +:Type: Boolean +:Required: No +:Default: ``false`` + + +``mon cluster log file`` + +:Description: The locations of the cluster's log files. There are two channels in + Ceph: ``cluster`` and ``audit``. This option represents a mapping + from channels to log files, where the log entries of that + channel are sent to. The ``default`` entry is a fallback + mapping for channels not explicitly specified. So, the following + default setting will send cluster log to ``$cluster.log``, and + send audit log to ``$cluster.audit.log``, where ``$cluster`` will + be replaced with the actual cluster name. +:Type: String +:Required: No +:Default: ``default=/var/log/ceph/$cluster.$channel.log,cluster=/var/log/ceph/$cluster.log`` + + + +OSD +--- + + +``osd debug drop ping probability`` + +:Description: ? +:Type: Double +:Required: No +:Default: 0 + + +``osd debug drop ping duration`` + +:Description: +:Type: Integer +:Required: No +:Default: 0 + +``osd debug drop pg create probability`` + +:Description: +:Type: Integer +:Required: No +:Default: 0 + +``osd debug drop pg create duration`` + +:Description: ? +:Type: Double +:Required: No +:Default: 1 + + +``osd min pg log entries`` + +:Description: The minimum number of log entries for placement groups. +:Type: 32-bit Unsigned Integer +:Required: No +:Default: 250 + + +``osd op log threshold`` + +:Description: How many op log messages to show up in one pass. +:Type: Integer +:Required: No +:Default: 5 + + + +Filestore +--------- + +``filestore debug omap check`` + +:Description: Debugging check on synchronization. This is an expensive operation. +:Type: Boolean +:Required: No +:Default: ``false`` + + +MDS +--- + + +``mds debug scatterstat`` + +:Description: Ceph will assert that various recursive stat invariants are true + (for developers only). + +:Type: Boolean +:Required: No +:Default: ``false`` + + +``mds debug frag`` + +:Description: Ceph will verify directory fragmentation invariants when + convenient (developers only). + +:Type: Boolean +:Required: No +:Default: ``false`` + + +``mds debug auth pins`` + +:Description: The debug auth pin invariants (for developers only). +:Type: Boolean +:Required: No +:Default: ``false`` + + +``mds debug subtrees`` + +:Description: The debug subtree invariants (for developers only). +:Type: Boolean +:Required: No +:Default: ``false`` + + + +RADOS Gateway +------------- + + +``rgw log nonexistent bucket`` + +:Description: Should we log a non-existent buckets? +:Type: Boolean +:Required: No +:Default: ``false`` + + +``rgw log object name`` + +:Description: Should an object's name be logged. // man date to see codes (a subset are supported) +:Type: String +:Required: No +:Default: ``%Y-%m-%d-%H-%i-%n`` + + +``rgw log object name utc`` + +:Description: Object log name contains UTC? +:Type: Boolean +:Required: No +:Default: ``false`` + + +``rgw enable ops log`` + +:Description: Enables logging of every RGW operation. +:Type: Boolean +:Required: No +:Default: ``true`` + + +``rgw enable usage log`` + +:Description: Enable logging of RGW's bandwidth usage. +:Type: Boolean +:Required: No +:Default: ``false`` + + +``rgw usage log flush threshold`` + +:Description: Threshold to flush pending log data. +:Type: Integer +:Required: No +:Default: ``1024`` + + +``rgw usage log tick interval`` + +:Description: Flush pending log data every ``s`` seconds. +:Type: Integer +:Required: No +:Default: 30 + + +``rgw intent log object name`` + +:Description: +:Type: String +:Required: No +:Default: ``%Y-%m-%d-%i-%n`` + + +``rgw intent log object name utc`` + +:Description: Include a UTC timestamp in the intent log object name. +:Type: Boolean +:Required: No +:Default: ``false`` + +.. [#] there are levels >20 in some rare cases and that they are extremely verbose. |