1 <?xml version="1.0" encoding="iso-8859-1"?>
2 <!DOCTYPE refentry PUBLIC "-//Samba-Team//DTD DocBook V4.2-Based Variant V1.0//EN" "http://www.samba.org/samba/DTD/samba-doc">
6 <refentrytitle>ctdb</refentrytitle>
7 <manvolnum>1</manvolnum>
12 <refname>ctdb</refname>
13 <refpurpose>clustered tdb database management utility</refpurpose>
18 <command>ctdb [ OPTIONS ] COMMAND ...</command>
22 <command>ctdb</command>
23 <arg choice="opt">-n <node></arg>
24 <arg choice="opt">-Y</arg>
25 <arg choice="opt">-t <timeout></arg>
26 <arg choice="opt">-T <timelimit></arg>
27 <arg choice="opt">-? --help</arg>
28 <arg choice="opt">--usage</arg>
29 <arg choice="opt">-d --debug=<INTEGER></arg>
30 <arg choice="opt">--socket=<filename></arg>
35 <refsect1><title>DESCRIPTION</title>
37 ctdb is a utility to view and manage a ctdb cluster.
43 <title>OPTIONS</title>
46 <varlistentry><term>-n <pnn></term>
49 This specifies the physical node number on which to execute the
50 command. Default is to run the command on the deamon running on
54 The physical node number is an integer that describes the node in the
55 cluster. The first node has physical node number 0.
60 <varlistentry><term>-Y</term>
63 Produce output in machine readable form for easier parsing by scripts. Not all commands support this option.
68 <varlistentry><term>-t <timeout></term>
71 How long should ctdb wait for the local ctdb daemon to respond to a command before timing out. Default is 3 seconds.
76 <varlistentry><term>-T <timelimit></term>
79 A limit on how long the ctdb command will run for before it will
80 be aborted. When this timelimit has been exceeded the ctdb command will
86 <varlistentry><term>-? --help</term>
89 Print some help text to the screen.
94 <varlistentry><term>--usage</term>
97 Print useage information to the screen.
102 <varlistentry><term>-d --debug=<debuglevel></term>
105 Change the debug level for the command. Default is 0.
110 <varlistentry><term>--socket=<filename></term>
113 Specify the socketname to use when connecting to the local ctdb
114 daemon. The default is /tmp/ctdb.socket .
117 You only need to specify this parameter if you run multiple ctdb
118 daemons on the same physical host and thus can not use the default
119 name for the domain socket.
128 <refsect1><title>Administrative Commands</title>
130 These are commands used to monitor and administrate a CTDB cluster.
133 <refsect2><title>status</title>
135 This command shows the current status of the ctdb node.
138 <refsect3><title>node status</title>
140 Node status reflects the current status of the node. There are four possible states:
143 OK - This node is fully functional.
146 DISCONNECTED - This node could not be connected through the network and is currently not participating in the cluster. If there is a public IP address associated with this node it should have been taken over by a different node. No services are running on this node.
149 DISABLED - This node has been administratively disabled. This node is still functional and participates in the CTDB cluster but its IP addresses have been taken over by a different node and no services are currently being hosted.
152 UNHEALTHY - A service provided by this node is malfunctioning and should be investigated. The CTDB daemon itself is operational and participates in the cluster. Its public IP address has been taken over by a different node and no services are currnetly being hosted. All unhealthy nodes should be investigated and require an administrative action to rectify.
155 BANNED - This node failed too many recovery attempts and has been banned from participating in the cluster for a period of RecoveryBanPeriod seconds. Any public IP address has been taken over by other nodes. This node does not provide any services. All banned nodes should be investigated and require an administrative action to rectify. This node does not perticipate in the CTDB cluster but can still be communicated with. I.e. ctdb commands can be sent to it.
159 <refsect3><title>generation</title>
161 The generation id is a number that indicates the current generation
162 of a cluster instance. Each time a cluster goes through a
163 reconfiguration or a recovery its generation id will be changed.
167 <refsect3><title>VNNMAP</title>
169 The list of Virtual Node Numbers. This is a list of all nodes that actively participates in the cluster and that share the workload of hosting the Clustered TDB database records.
170 Only nodes that are participating in the vnnmap can become lmaster or dmaster for a database record.
174 <refsect3><title>Recovery mode</title>
176 This is the current recovery mode of the cluster. There are two possible modes:
179 NORMAL - The cluster is fully operational.
182 RECOVERY - The cluster databases have all been frozen, pausing all services while the cluster awaits a recovery process to complete. A recovery process should finish within seconds. If a cluster is stuck in the RECOVERY state this would indicate a cluster malfunction which needs to be investigated.
186 <refsect3><title>Recovery master</title>
188 This is the cluster node that is currently designated as the recovery master. This node is responsible of monitoring the consistency of the cluster and to perform the actual recovery process when reqired.
195 <para>Example output:</para>
196 <screen format="linespecific">
198 pnn:0 11.1.2.200 OK (THIS NODE)
202 Generation:1362079228
208 Recovery mode:NORMAL (0)
213 <refsect2><title>ping</title>
215 This command will "ping" all CTDB daemons in the cluster to verify that they are processing commands correctly.
223 <screen format="linespecific">
224 response from 0 time=0.000054 sec (3 clients)
225 response from 1 time=0.000144 sec (2 clients)
226 response from 2 time=0.000105 sec (2 clients)
227 response from 3 time=0.000114 sec (2 clients)
231 <refsect2><title>ip</title>
233 This command will display the list of public addresses that are provided by the cluster and which physical node is currently serving this ip.
241 <screen format="linespecific">
242 Number of addresses:4
250 <refsect2><title>getvar <name></title>
252 Get the runtime value of a tuneable variable.
255 Example: ctdb getvar MaxRedirectCount
260 <screen format="linespecific">
265 <refsect2><title>setvar <name> <value></title>
267 Set the runtime value of a tuneable variable.
270 Example: ctdb setvar MaxRedirectCount 5
274 <refsect2><title>listvars</title>
276 List all tuneable variables.
279 Example: ctdb listvars
284 <screen format="linespecific">
289 KeepaliveInterval = 2
297 EventScriptTimeout = 20
298 RecoveryGracePeriod = 60
299 RecoveryBanPeriod = 300
303 <refsect2><title>statistics</title>
305 Collect statistics from the CTDB daemon about how many calls it has served.
308 Example: ctdb statistics
313 <screen format="linespecific">
318 client_packets_sent 360489
319 client_packets_recv 360466
320 node_packets_sent 480931
321 node_packets_recv 240120
322 keepalive_packets_sent 4
323 keepalive_packets_recv 3
344 pending_lockwait_calls 0
347 max_call_latency 4.948321 sec
348 max_lockwait_latency 0.000000 sec
352 <refsect2><title>statisticsreset</title>
354 This command is used to clear all statistics counters in a node.
357 Example: ctdb statisticsreset
361 <refsect2><title>getdebug</title>
363 Get the current debug level for the node. the debug level controls what information is written to the log file.
367 <refsect2><title>setdebug <debuglevel></title>
369 Set the debug level of a node. This is a number between 0 and 9 and controls what information will be written to the logfile.
373 <refsect2><title>getpid</title>
375 This command will return the process id of the ctdb daemon.
379 <refsect2><title>disable</title>
381 This command is used to administratively disable a node in the cluster.
382 A disabled node will still participate in the cluster and host
383 clustered TDB records but its public ip address has been taken over by
384 a different node and it no longer hosts any services.
388 <refsect2><title>enable</title>
390 Re-enable a node that has been administratively disabled.
394 <refsect2><title>ban <bantime|0></title>
396 Administratively ban a node for bantime seconds. A bantime of 0 means that the node should be permanently banned.
399 A banned node does not participate in the cluster and does not host any records for the clustered TDB. Its ip address has been taken over by an other node and no services are hosted.
402 Nodes are automatically banned if they are the cause of too many
407 <refsect2><title>unban</title>
409 This command is used to unban a node that has either been
410 administratively banned using the ban command or has been automatically
411 banned by the recovery daemon.
415 <refsect2><title>shutdown</title>
417 This command will shutdown a specific CTDB daemon.
421 <refsect2><title>recover</title>
423 This command will trigger the recovery daemon to do a cluster
428 <refsect2><title>killtcp <srcip:port> <dstip:port></title>
430 This command will kill the specified TCP connection by issuing a
431 TCP RST to the srcip:port endpoint.
435 <refsect2><title>tickle <srcip:port> <dstip:port></title>
437 This command will will send a TCP tickle to the source host for the
438 specified TCP connection.
439 A TCP tickle is a TCP ACK packet with an invalid sequence and
440 acknowledge number and will when received by the source host result
441 in it sending an immediate correct ACK back to the other end.
444 TCP tickles are useful to "tickle" clients after a IP failover has
445 occured since this will make the client immediately recognize the
446 TCP connection has been disrupted and that the client will need
447 to reestablish. This greatly speeds up the time it takes for a client
448 to detect and reestablish after an IP failover in the ctdb cluster.
452 <refsect2><title>repack [max_freelist]</title>
454 Over time, when records are created and deleted in a TDB, the TDB list of free space will become fragmented. This can lead to a slowdown in accessing TDB records.
455 This command is used to defragment a TDB database and pruning the freelist.
459 If [max_freelist] is specified, then a database will only be repacked if it has more than this number of entries in the freelist.
462 During repacking of the database, the entire TDB database will be locked to prevent writes. If samba tries to write to a record in the database during a repack operation, samba will block until the repacking has completed.
466 This command can be disruptive and can cause samba to block for the duration of the repack operation. In general, a repack operation will take less than one second to complete.
470 A repack operation will only defragment the local TDB copy of the CTDB database. You need to run this command on all of the nodes to repack a CTDB database completely.
474 Example: ctdb repack 1000
478 By default, this operation is issued from the 00.ctdb event script every 5 minutes.
483 <refsect2><title>vacuum [max_records]</title>
485 Over time CTDB databases will fill up with empty deleted records which will lead to a progressive slow down of CTDB database access.
486 This command is used to prune all databases and delete all empty records from the cluster.
490 By default, vacuum will delete all empty records from all databases.
491 If [max_records] is specified, the command will only delete the first
492 [max_records] empty records for each database.
496 Vacuum only deletes records where the local node is the lmaster.
497 To delete all records from the entire cluster you need to run a vacuum from each node.
499 This command is not disruptive. Samba is unaffected and will still be able to read/write records normally while the database is being vacuumed.
507 By default, this operation is issued from the 00.ctdb event script every 5 minutes.
514 <refsect1><title>Debugging Commands</title>
516 These commands are primarily used for CTDB development and testing and
517 should not be used for normal administration.
519 <refsect2><title>process-exists <pid></title>
521 This command checks if a specific process exists on the CTDB host. This is mainly used by Samba to check if remote instances of samba are still running or not.
525 <refsect2><title>getdbmap</title>
527 This command lists all clustered TDB databases that the CTDB daemon has attahced to.
530 Example: ctdb getdbmap
535 <screen format="linespecific">
536 Number of databases:4
537 dbid:0x42fe72c5 name:locking.tdb path:/var/ctdb/locking.tdb.0
538 dbid:0x1421fb78 name:brlock.tdb path:/var/ctdb/brlock.tdb.0
539 dbid:0x17055d90 name:connections.tdb path:/var/ctdb/connections.tdb.0
540 dbid:0xc0bdde6a name:sessionid.tdb path:/var/ctdb/sessionid.tdb.0
544 <refsect2><title>catdb <dbname></title>
546 This command will dump a clustered TDB database to the screen. This is a debugging command.
550 <refsect2><title>getmonmode</title>
552 This command returns the monutoring mode of a node. The monitoring mode is either ACTIVE or DISABLED. Normally a node will continously monitor that all other nodes that are expected are in fact connected and that they respond to commands.
555 ACTIVE - This is the normal mode. The node is actively monitoring all other nodes, both that the transport is connected and also that the node responds to commands. If a node becomes unavailable, it will be marked as DISCONNECTED and a recovery is initiated to restore the cluster.
558 DISABLED - This node is not monitoring that other nodes are available. In this mode a node failure will not be detected and no recovery will be performed. This mode is useful when for debugging purposes one wants to attach GDB to a ctdb process but wants to prevent the rest of the cluster from marking this node as DISCONNECTED and do a recovery.
563 <refsect2><title>setmonmode <0|1></title>
565 This command can be used to explicitely disable/enable monitoring mode on a node. The main purpose is if one wants to attach GDB to a running ctdb daemon but wants to prevent the other nodes from marking it as DISCONNECTED and issuing a recovery. To do this, set monitoring mode to 0 on all nodes before attaching with GDB. Remember to set monitoring mode back to 1 afterwards.
569 <refsect2><title>attach <dbname></title>
571 This is a debugging command. This command will make the CTDB daemon create a new CTDB database and attach to it.
575 <refsect2><title>dumpmemory</title>
577 This is a debugging command. This command will make the ctdb daemon to write a fill memory allocation map to the log file.
581 <refsect2><title>freeze</title>
583 This command will lock all the local TDB databases causing clients
584 that are accessing these TDBs such as samba3 to block until the
585 databases are thawed.
588 This is primarily used by the recovery daemon to stop all samba
589 daemons from accessing any databases while the database is recovered
594 <refsect2><title>thaw</title>
596 Thaw a previously frozen node.
603 <refsect1><title>SEE ALSO</title>
606 <ulink url="http://ctdb.samba.org/"/>
609 <refsect1><title>COPYRIGHT/LICENSE</title>
611 Copyright (C) Andrew Tridgell 2007
612 Copyright (C) Ronnie sahlberg 2007
614 This program is free software; you can redistribute it and/or modify
615 it under the terms of the GNU General Public License as published by
616 the Free Software Foundation; either version 3 of the License, or (at
617 your option) any later version.
619 This program is distributed in the hope that it will be useful, but
620 WITHOUT ANY WARRANTY; without even the implied warranty of
621 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
622 General Public License for more details.
624 You should have received a copy of the GNU General Public License
625 along with this program; if not, see http://www.gnu.org/licenses/.