ctdb-statistics.7.xml

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<refentry id="ctdb-statistics.7">

  <refmeta>
    <refentrytitle>ctdb-statistics</refentrytitle>
    <manvolnum>7</manvolnum>
    <refmiscinfo class="source">ctdb</refmiscinfo>
    <refmiscinfo class="manual">CTDB - clustered TDB database</refmiscinfo>
  </refmeta>

  <refnamediv>
    <refname>ctdb-statistics</refname>
    <refpurpose>CTDB statistics output</refpurpose>
  </refnamediv>

  <refsect1>
    <title>OVERALL STATISTICS</title>

    <para>
      CTDB maintains information about various messages communicated
      and some of the important operations per node.  See the
      <citerefentry><refentrytitle>ctdb</refentrytitle>
      <manvolnum>1</manvolnum></citerefentry> commands
      <command>statistics</command> and <command>statisticsreset</command>
      for displaying statistics.
    </para>

      <refsect2>
	<title>Example: ctdb statistics</title>
	<screen>
CTDB version 1
Current time of statistics  :                Fri Sep 12 13:32:32 2014
Statistics collected since  : (000 01:49:20) Fri Sep 12 11:43:12 2014
 num_clients                        6
 frozen                             0
 recovering                         0
 num_recoveries                     2
 client_packets_sent           281293
 client_packets_recv           296317
 node_packets_sent             452387
 node_packets_recv             182394
 keepalive_packets_sent          3927
 keepalive_packets_recv          3928
 node
     req_call                   48605
     reply_call                     1
     req_dmaster                23404
     reply_dmaster              24917
     reply_error                    0
     req_message                  958
     req_control               197513
     reply_control             153705
 client
     req_call                  130866
     req_message                  770
     req_control               168921
 timeouts
     call                           0
     control                        0
     traverse                       0
 locks
     num_calls                    220
     num_current                    0
     num_pending                    0
     num_failed                     0
 total_calls                   130866
 pending_calls                      0
 childwrite_calls                   1
 pending_childwrite_calls             0
 memory_used                   334490
 max_hop_count                     18
 total_ro_delegations               2
 total_ro_revokes                   2
 hop_count_buckets: 42816 5464 26 1 0 0 0 0 0 0 0 0 0 0 0 0
 lock_buckets: 9 165 14 15 7 2 2 0 0 0 0 0 0 0 0 0
 locks_latency      MIN/AVG/MAX     0.000685/0.160302/6.369342 sec out of 214
 reclock_ctdbd      MIN/AVG/MAX     0.004940/0.004969/0.004998 sec out of 2
 reclock_recd       MIN/AVG/MAX     0.000000/0.000000/0.000000 sec out of 0
 call_latency       MIN/AVG/MAX     0.000006/0.000719/4.562991 sec out of 126626
 childwrite_latency MIN/AVG/MAX     0.014527/0.014527/0.014527 sec out of 1
	</screen>
      </refsect2>

    <refsect2>
      <title>CTDB version</title>
      <para>
        Version of the ctdb protocol used by the node.
      </para>
    </refsect2>

    <refsect2>
      <title>Current time of statistics</title>
      <para>
        Time when the statistics are generated.
      </para>
      <para>
        This is useful when collecting statistics output periodically
        for post-processing.
      </para>
    </refsect2>

    <refsect2>
      <title>Statistics collected since</title>
      <para>
	Time when ctdb was started or the last time statistics was reset.
	The output shows the duration and the timestamp.
      </para>
    </refsect2>

    <refsect2>
      <title>num_clients</title>
      <para>
        Number of processes currently connected to CTDB's unix socket.
        This includes recovery daemon, ctdb tool and samba processes
        (smbd, winbindd).
      </para>
    </refsect2>

    <refsect2>
      <title>frozen</title>
      <para>
	1 if the databases are currently frozen, 0 otherwise.
      </para>
    </refsect2>

    <refsect2>
      <title>recovering</title>
      <para>
	1 if recovery is active, 0 otherwise.
      </para>
    </refsect2>

    <refsect2>
      <title>num_recoveries</title>
      <para>
	Number of recoveries since the start of ctdb or since the last
	statistics reset.
      </para>
    </refsect2>

    <refsect2>
      <title>client_packets_sent</title>
      <para>
	Number of packets sent to client processes via unix domain socket.
      </para>
    </refsect2>

    <refsect2>
      <title>client_packets_recv</title>
      <para>
	Number of packets received from client processes via unix domain socket.
      </para>
    </refsect2>

    <refsect2>
      <title>node_packets_sent</title>
      <para>
	Number of packets sent to the other nodes in the cluster via TCP.
      </para>
    </refsect2>

    <refsect2>
      <title>node_packets_recv</title>
      <para>
	Number of packets received from the other nodes in the cluster via TCP.
      </para>
    </refsect2>

    <refsect2>
      <title>keepalive_packets_sent</title>
      <para>
	Number of keepalive messages sent to other nodes.
      </para>
      <para>
	CTDB periodically sends keepalive messages to other nodes.
	See <citetitle>KeepaliveInterval</citetitle> tunable in
	<citerefentry><refentrytitle>ctdb-tunables</refentrytitle>
	<manvolnum>7</manvolnum></citerefentry> for more details.
      </para>
    </refsect2>

    <refsect2>
      <title>keepalive_packets_recv</title>
      <para>
	Number of keepalive messages received from other nodes.
      </para>
    </refsect2>

    <refsect2>
      <title>node</title>
      <para>
	This section lists various types of messages processed which
	originated from other nodes via TCP.
      </para>

    <refsect3>
      <title>req_call</title>
      <para>
        Number of REQ_CALL messages from the other nodes.
      </para>
    </refsect3>

    <refsect3>
      <title>reply_call</title>
      <para>
        Number of REPLY_CALL messages from the other nodes.
      </para>
    </refsect3>

    <refsect3>
      <title>req_dmaster</title>
      <para>
        Number of REQ_DMASTER messages from the other nodes.
      </para>
    </refsect3>

    <refsect3>
      <title>reply_dmaster</title>
      <para>
        Number of REPLY_DMASTER messages from the other nodes.
      </para>
    </refsect3>

    <refsect3>
      <title>reply_error</title>
      <para>
        Number of REPLY_ERROR messages from the other nodes.
      </para>
    </refsect3>

    <refsect3>
      <title>req_message</title>
      <para>
        Number of REQ_MESSAGE messages from the other nodes.
      </para>
    </refsect3>

    <refsect3>
      <title>req_control</title>
      <para>
        Number of REQ_CONTROL messages from the other nodes.
      </para>
    </refsect3>

    <refsect3>
      <title>reply_control</title>
      <para>
        Number of REPLY_CONTROL messages from the other nodes.
      </para>
    </refsect3>

    <refsect3>
      <title>req_tunnel</title>
      <para>
        Number of REQ_TUNNEL messages from the other nodes.
      </para>
    </refsect3>

    </refsect2>

    <refsect2>
      <title>client</title>
      <para>
	This section lists various types of messages processed which
	originated from clients via unix domain socket.
      </para>

    <refsect3>
      <title>req_call</title>
      <para>
        Number of REQ_CALL messages from the clients.
      </para>
    </refsect3>

    <refsect3>
      <title>req_message</title>
      <para>
        Number of REQ_MESSAGE messages from the clients.
      </para>
    </refsect3>

    <refsect3>
      <title>req_control</title>
      <para>
        Number of REQ_CONTROL messages from the clients.
      </para>
    </refsect3>

    <refsect3>
      <title>req_tunnel</title>
      <para>
        Number of REQ_TUNNEL messages from the clients.
      </para>
    </refsect3>

    </refsect2>

    <refsect2>
      <title>timeouts</title>
      <para>
	This section lists timeouts occurred when sending various messages.
      </para>

    <refsect3>
      <title>call</title>
      <para>
        Number of timeouts for REQ_CALL messages.
      </para>
    </refsect3>

    <refsect3>
      <title>control</title>
      <para>
        Number of timeouts for REQ_CONTROL messages.
      </para>
    </refsect3>

    <refsect3>
      <title>traverse</title>
      <para>
        Number of timeouts for database traverse operations.
      </para>
    </refsect3>
    </refsect2>

    <refsect2>
      <title>locks</title>
      <para>
	This section lists locking statistics.
      </para>

    <refsect3>
      <title>num_calls</title>
      <para>
        Number of completed lock calls.  This includes database locks
        and record locks.
      </para>
    </refsect3>

    <refsect3>
      <title>num_current</title>
      <para>
        Number of scheduled lock calls.  This includes database locks
        and record locks.
      </para>
    </refsect3>

    <refsect3>
      <title>num_pending</title>
      <para>
        Number of queued lock calls.  This includes database locks and
        record locks.
      </para>
    </refsect3>

    <refsect3>
      <title>num_failed</title>
      <para>
        Number of failed lock calls.  This includes database locks and
        record locks.
      </para>
    </refsect3>

    </refsect2>

    <refsect2>
      <title>total_calls</title>
      <para>
	Number of req_call messages processed from clients.  This number
	should be same as client --> req_call.
      </para>
    </refsect2>

    <refsect2>
      <title>pending_calls</title>
      <para>
	Number of req_call messages which are currently being processed.
	This number indicates the number of record migrations in flight.
      </para>
    </refsect2>

    <refsect2>
      <title>childwrite_calls</title>
      <para>
	Number of record update calls.	Record update calls are used to
	update a record under a transaction.
      </para>
    </refsect2>

    <refsect2>
      <title>pending_childwrite_calls</title>
      <para>
	Number of record update calls currently active.
      </para>
    </refsect2>

    <refsect2>
      <title>memory_used</title>
      <para>
	The amount of memory in bytes currently used by CTDB using
	talloc.  This includes all the memory used for CTDB's internal
	data structures.  This does not include the memory mapped TDB
	databases.
      </para>
    </refsect2>

    <refsect2>
      <title>max_hop_count</title>
      <para>
	The maximum number of hops required for a record migration request
	to obtain the record.  High numbers indicate record contention.
      </para>
    </refsect2>

    <refsect2>
      <title>total_ro_delegations</title>
      <para>
	Number of readonly delegations created.
      </para>
    </refsect2>

    <refsect2>
      <title>total_ro_revokes</title>
      <para>
	Number of readonly delegations that were revoked.  The difference
	between total_ro_revokes and total_ro_delegations gives the
	number of currently active readonly delegations.
      </para>
    </refsect2>

    <refsect2>
      <title>hop_count_buckets</title>
      <para>
	Distribution of migration requests based on hop counts values.
	Buckets are 0, &lt;&nbsp;2, &lt;&nbsp;4, &lt;&nbsp;8,
	&lt;&nbsp;16, &lt;&nbsp;32, &lt;&nbsp;64, &lt;&nbsp;128,
	&lt;&nbsp;256, &lt;&nbsp;512, &lt;&nbsp;1024, &lt;&nbsp;2048,
	&lt;&nbsp;4096, &lt;&nbsp;8192, &lt;&nbsp;16384, &ge;&nbsp;16384.
      </para>
    </refsect2>

    <refsect2>
      <title>lock_buckets</title>
      <para>
	Distribution of record lock requests based on time required to
	obtain locks.  Buckets are &lt;&nbsp;1ms, &lt;&nbsp;10ms,
	&lt;&nbsp;100ms, &lt;&nbsp;1s, &lt;&nbsp;2s, &lt;&nbsp;4s,
	&lt;&nbsp;8s, &lt;&nbsp;16s, &lt;&nbsp;32s, &lt;&nbsp;64s,
	&ge;&nbsp;64s.
      </para>
    </refsect2>

    <refsect2>
      <title>locks_latency</title>
      <para>
	The minimum, the average and the maximum time (in seconds)
	required to obtain record locks.
      </para>
    </refsect2>

    <refsect2>
      <title>reclock_ctdbd</title>
      <para>
	The minimum, the average and the maximum time (in seconds)
	required to check if recovery lock is still held by recovery
	daemon when recovery mode is changed.  This check is done in ctdb daemon.
      </para>
    </refsect2>

    <refsect2>
      <title>reclock_recd</title>
      <para>
        The minimum, the average and the maximum time (in seconds)
        required to check if recovery lock is still held by recovery
        daemon during recovery.  This check is done in recovery daemon.
      </para>
    </refsect2>

    <refsect2>
      <title>call_latency</title>
      <para>
	The minimum, the average and the maximum time (in seconds) required
	to process a REQ_CALL message from client.  This includes the time
	required to migrate a record from remote node, if the record is
	not available on the local node.
      </para>
    </refsect2>

    <refsect2>
      <title>childwrite_latency</title>
      <para>Default: 0</para>
      <para>
	The minimum, the average and the maximum time (in seconds)
	required to update records under a transaction.
      </para>
    </refsect2>
  </refsect1>

  <refsect1>
    <title>DATABASE STATISTICS</title>

    <para>
      CTDB maintains per database statistics about important operations.
      See the <citerefentry><refentrytitle>ctdb</refentrytitle>
      <manvolnum>1</manvolnum></citerefentry> command
      <command>dbstatistics</command> for displaying database statistics.
    </para>

    <refsect2>
	<title>Example: ctdb dbstatistics notify_index.tdb</title>
	<screen>
DB Statistics: notify_index.tdb
 ro_delegations                     0
 ro_revokes                         0
 locks
     total                        131
     failed                         0
     current                        0
     pending                        0
 hop_count_buckets: 9890 5454 26 1 0 0 0 0 0 0 0 0 0 0 0 0
 lock_buckets: 4 117 10 0 0 0 0 0 0 0 0 0 0 0 0 0
 locks_latency      MIN/AVG/MAX     0.000683/0.004198/0.014730 sec out of 131
 Num Hot Keys:     3
     Count:7 Key:2f636c75737465726673
     Count:18 Key:2f636c757374657266732f64617461
     Count:7 Key:2f636c757374657266732f646174612f636c69656e7473
	</screen>
    </refsect2>

    <refsect2>
      <title>DB Statistics</title>
      <para>
	Name of the database.
      </para>
    </refsect2>

    <refsect2>
      <title>ro_delegations</title>
      <para>
	Number of readonly delegations created in the database.
      </para>
    </refsect2>

    <refsect2>
      <title>ro_revokes</title>
      <para>
	Number of readonly delegations revoked.  The difference in
	ro_delegations and ro_revokes indicates the currently active
	readonly delegations.
      </para>
    </refsect2>

    <refsect2>
      <title>locks</title>
      <para>
	This section lists locking statistics.
      </para>

    <refsect3>
      <title>total</title>
      <para>
        Number of completed lock calls.  This includes database locks
        and record locks.
      </para>
    </refsect3>

    <refsect3>
      <title>failed</title>
      <para>
        Number of failed lock calls.  This includes database locks and
        record locks.
      </para>
    </refsect3>

    <refsect3>
      <title>current</title>
      <para>
        Number of scheduled lock calls.  This includes database locks
        and record locks.
      </para>
    </refsect3>

    <refsect3>
      <title>pending</title>
      <para>
        Number of queued lock calls.  This includes database locks and
        record locks.
      </para>
    </refsect3>

    </refsect2>

    <refsect2>
      <title>hop_count_buckets</title>
      <para>
	Distribution of migration requests based on hop counts values.
	Buckets are 0, &lt;&nbsp;2, &lt;&nbsp;4, &lt;&nbsp;8,
	&lt;&nbsp;16, &lt;&nbsp;32, &lt;&nbsp;64, &lt;&nbsp;128,
	&lt;&nbsp;256, &lt;&nbsp;512, &lt;&nbsp;1024, &lt;&nbsp;2048,
	&lt;&nbsp;4096, &lt;&nbsp;8192, &lt;&nbsp;16384, &ge;&nbsp;16384.
      </para>
    </refsect2>

    <refsect2>
      <title>lock_buckets</title>
      <para>
	Distribution of record lock requests based on time required to
	obtain locks.  Buckets are &lt;&nbsp;1ms, &lt;&nbsp;10ms,
	&lt;&nbsp;100ms, &lt;&nbsp;1s, &lt;&nbsp;2s, &lt;&nbsp;4s,
	&lt;&nbsp;8s, &lt;&nbsp;16s, &lt;&nbsp;32s, &lt;&nbsp;64s,
	&ge;&nbsp;64s.
      </para>
    </refsect2>

    <refsect2>
      <title>locks_latency</title>
      <para>
	The minimum, the average and the maximum time (in seconds)
	required to obtain record locks.
      </para>
    </refsect2>

    <refsect2>
      <title>Num Hot Keys</title>
      <para>
        Number of contended records determined by hop count.  CTDB keeps
        track of top 10 hot records and the output shows hex encoded
        keys for the hot records.
      </para>
    </refsect2>
  </refsect1>

  <refsect1>
    <title>SEE ALSO</title>
    <para>
      <citerefentry><refentrytitle>ctdb</refentrytitle>
      <manvolnum>1</manvolnum></citerefentry>,

      <citerefentry><refentrytitle>ctdbd</refentrytitle>
      <manvolnum>1</manvolnum></citerefentry>,

      <citerefentry><refentrytitle>ctdb-tunables</refentrytitle>
      <manvolnum>7</manvolnum></citerefentry>,

      <ulink url="http://ctdb.samba.org/"/>
    </para>
  </refsect1>

  <refentryinfo>
    <author>
      <contrib>
	This documentation was written by
	Amitay Isaacs,
	Martin Schwenke
      </contrib>
    </author>

    <copyright>
      <year>2007</year>
      <holder>Andrew Tridgell</holder>
      <holder>Ronnie Sahlberg</holder>
    </copyright>
    <legalnotice>
      <para>
	This program is free software; you can redistribute it and/or
	modify it under the terms of the GNU General Public License as
	published by the Free Software Foundation; either version 3 of
	the License, or (at your option) any later version.
      </para>
      <para>
	This program is distributed in the hope that it will be
	useful, but WITHOUT ANY WARRANTY; without even the implied
	warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
	PURPOSE.  See the GNU General Public License for more details.
      </para>
      <para>
	You should have received a copy of the GNU General Public
	License along with this program; if not, see
	<ulink url="http://www.gnu.org/licenses"/>.
      </para>
    </legalnotice>
  </refentryinfo>

</refentry>