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.
166 This number does not have any particular meaning other than to keep
167 track of when a cluster has gone through a recovery. It is a random
168 number that represents the current instance of a ctdb cluster
170 CTDBD uses this number internally to be able to tell when commands
171 to operate on the cluster and the databases was issued in a different
172 generation of the cluster, to ensure that commands that operate
173 on the databases will not survive across a cluster database recovery.
174 After a recovery, all old outstanding commands will automatically
178 Sometimes this number will be shown as "INVALID". This only means that
179 the ctdbd daemon has started but it has not yet merged with the cluster through a recovery.
180 All nodes start with generation "INVALID" and are not assigned a real
181 generation id until they have successfully been merged with a cluster
186 <refsect3><title>VNNMAP</title>
188 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.
189 Only nodes that are participating in the vnnmap can become lmaster or dmaster for a database record.
193 <refsect3><title>Recovery mode</title>
195 This is the current recovery mode of the cluster. There are two possible modes:
198 NORMAL - The cluster is fully operational.
201 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.
204 Once the recovery master detects an inconsistency, for example a node
205 becomes disconnected/connected, the recovery daemon will trigger a
206 cluster recovery process, where all databases are remerged across the
207 cluster. When this process starts, the recovery master will first
208 "freeze" all databases to prevent applications such as samba from
209 accessing the databases and it will also mark the recovery mode as
213 When CTDBD starts up, it will start in RECOVERY mode.
214 Once the node has been merged into a cluster and all databases
215 have been recovered, the node mode will change into NORMAL mode
216 and the databases will be "thawed", allowing samba to access the
221 <refsect3><title>Recovery master</title>
223 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.
226 Only one node at a time can be the designated recovery master. Which
227 node is designated the recovery master is decided by an election
228 process in the recovery daemons running on each node.
235 <para>Example output:</para>
236 <screen format="linespecific">
238 pnn:0 11.1.2.200 OK (THIS NODE)
242 Generation:1362079228
248 Recovery mode:NORMAL (0)
253 <refsect2><title>ping</title>
255 This command will "ping" all CTDB daemons in the cluster to verify that they are processing commands correctly.
263 <screen format="linespecific">
264 response from 0 time=0.000054 sec (3 clients)
265 response from 1 time=0.000144 sec (2 clients)
266 response from 2 time=0.000105 sec (2 clients)
267 response from 3 time=0.000114 sec (2 clients)
271 <refsect2><title>ip</title>
273 This command will display the list of public addresses that are provided by the cluster and which physical node is currently serving this ip.
281 <screen format="linespecific">
282 Number of addresses:4
290 <refsect2><title>getvar <name></title>
292 Get the runtime value of a tuneable variable.
295 Example: ctdb getvar MaxRedirectCount
300 <screen format="linespecific">
305 <refsect2><title>setvar <name> <value></title>
307 Set the runtime value of a tuneable variable.
310 Example: ctdb setvar MaxRedirectCount 5
314 <refsect2><title>listvars</title>
316 List all tuneable variables.
319 Example: ctdb listvars
324 <screen format="linespecific">
329 KeepaliveInterval = 2
337 EventScriptTimeout = 20
338 RecoveryGracePeriod = 60
339 RecoveryBanPeriod = 300
343 <refsect2><title>statistics</title>
345 Collect statistics from the CTDB daemon about how many calls it has served.
348 Example: ctdb statistics
353 <screen format="linespecific">
358 client_packets_sent 360489
359 client_packets_recv 360466
360 node_packets_sent 480931
361 node_packets_recv 240120
362 keepalive_packets_sent 4
363 keepalive_packets_recv 3
384 pending_lockwait_calls 0
387 max_call_latency 4.948321 sec
388 max_lockwait_latency 0.000000 sec
392 <refsect2><title>statisticsreset</title>
394 This command is used to clear all statistics counters in a node.
397 Example: ctdb statisticsreset
401 <refsect2><title>getdebug</title>
403 Get the current debug level for the node. the debug level controls what information is written to the log file.
407 <refsect2><title>setdebug <debuglevel></title>
409 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.
413 <refsect2><title>getpid</title>
415 This command will return the process id of the ctdb daemon.
419 <refsect2><title>disable</title>
421 This command is used to administratively disable a node in the cluster.
422 A disabled node will still participate in the cluster and host
423 clustered TDB records but its public ip address has been taken over by
424 a different node and it no longer hosts any services.
428 <refsect2><title>enable</title>
430 Re-enable a node that has been administratively disabled.
434 <refsect2><title>ban <bantime|0></title>
436 Administratively ban a node for bantime seconds. A bantime of 0 means that the node should be permanently banned.
439 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.
442 Nodes are automatically banned if they are the cause of too many
447 <refsect2><title>unban</title>
449 This command is used to unban a node that has either been
450 administratively banned using the ban command or has been automatically
451 banned by the recovery daemon.
455 <refsect2><title>shutdown</title>
457 This command will shutdown a specific CTDB daemon.
461 <refsect2><title>recover</title>
463 This command will trigger the recovery daemon to do a cluster
468 <refsect2><title>killtcp <srcip:port> <dstip:port></title>
470 This command will kill the specified TCP connection by issuing a
471 TCP RST to the srcip:port endpoint.
475 <refsect2><title>tickle <srcip:port> <dstip:port></title>
477 This command will will send a TCP tickle to the source host for the
478 specified TCP connection.
479 A TCP tickle is a TCP ACK packet with an invalid sequence and
480 acknowledge number and will when received by the source host result
481 in it sending an immediate correct ACK back to the other end.
484 TCP tickles are useful to "tickle" clients after a IP failover has
485 occured since this will make the client immediately recognize the
486 TCP connection has been disrupted and that the client will need
487 to reestablish. This greatly speeds up the time it takes for a client
488 to detect and reestablish after an IP failover in the ctdb cluster.
492 <refsect2><title>repack [max_freelist]</title>
494 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.
495 This command is used to defragment a TDB database and pruning the freelist.
499 If [max_freelist] is specified, then a database will only be repacked if it has more than this number of entries in the freelist.
502 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.
506 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.
510 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.
514 Example: ctdb repack 1000
518 By default, this operation is issued from the 00.ctdb event script every 5 minutes.
523 <refsect2><title>vacuum [max_records]</title>
525 Over time CTDB databases will fill up with empty deleted records which will lead to a progressive slow down of CTDB database access.
526 This command is used to prune all databases and delete all empty records from the cluster.
530 By default, vacuum will delete all empty records from all databases.
531 If [max_records] is specified, the command will only delete the first
532 [max_records] empty records for each database.
536 Vacuum only deletes records where the local node is the lmaster.
537 To delete all records from the entire cluster you need to run a vacuum from each node.
539 This command is not disruptive. Samba is unaffected and will still be able to read/write records normally while the database is being vacuumed.
547 By default, this operation is issued from the 00.ctdb event script every 5 minutes.
554 <refsect1><title>Debugging Commands</title>
556 These commands are primarily used for CTDB development and testing and
557 should not be used for normal administration.
559 <refsect2><title>process-exists <pid></title>
561 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.
565 <refsect2><title>getdbmap</title>
567 This command lists all clustered TDB databases that the CTDB daemon has attached to. Some databases are flagged as PERSISTENT, this means that the database stores data persistently and the data will remain across reboots. One example of such a database is secrets.tdb where information about how the cluster was joined to the domain is stored.
570 Most databases are not persistent and only store the state information that the currently running samba daemons need. These databases are always wiped when ctdb/samba starts and when a node is rebooted.
573 Example: ctdb getdbmap
578 <screen format="linespecific">
579 Number of databases:10
580 dbid:0x435d3410 name:notify.tdb path:/var/ctdb/notify.tdb.0
581 dbid:0x42fe72c5 name:locking.tdb path:/var/ctdb/locking.tdb.0 dbid:0x1421fb78 name:brlock.tdb path:/var/ctdb/brlock.tdb.0
582 dbid:0x17055d90 name:connections.tdb path:/var/ctdb/connections.tdb.0
583 dbid:0xc0bdde6a name:sessionid.tdb path:/var/ctdb/sessionid.tdb.0
584 dbid:0x122224da name:test.tdb path:/var/ctdb/test.tdb.0
585 dbid:0x2672a57f name:idmap2.tdb path:/var/ctdb/persistent/idmap2.tdb.0 PERSISTENT
586 dbid:0xb775fff6 name:secrets.tdb path:/var/ctdb/persistent/secrets.tdb.0 PERSISTENT
587 dbid:0xe98e08b6 name:group_mapping.tdb path:/var/ctdb/persistent/group_mapping.tdb.0 PERSISTENT
588 dbid:0x7bbbd26c name:passdb.tdb path:/var/ctdb/persistent/passdb.tdb.0 PERSISTENT
592 <refsect2><title>catdb <dbname></title>
594 This command will dump a clustered TDB database to the screen. This is a debugging command.
598 <refsect2><title>getmonmode</title>
600 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.
603 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.
606 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.
611 <refsect2><title>setmonmode <0|1></title>
613 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.
617 <refsect2><title>attach <dbname></title>
619 This is a debugging command. This command will make the CTDB daemon create a new CTDB database and attach to it.
623 <refsect2><title>dumpmemory</title>
625 This is a debugging command. This command will make the ctdb daemon to write a fill memory allocation map to the log file.
629 <refsect2><title>freeze</title>
631 This command will lock all the local TDB databases causing clients
632 that are accessing these TDBs such as samba3 to block until the
633 databases are thawed.
636 This is primarily used by the recovery daemon to stop all samba
637 daemons from accessing any databases while the database is recovered
642 <refsect2><title>thaw</title>
644 Thaw a previously frozen node.
651 <refsect1><title>SEE ALSO</title>
654 <ulink url="http://ctdb.samba.org/"/>
657 <refsect1><title>COPYRIGHT/LICENSE</title>
659 Copyright (C) Andrew Tridgell 2007
660 Copyright (C) Ronnie sahlberg 2007
662 This program is free software; you can redistribute it and/or modify
663 it under the terms of the GNU General Public License as published by
664 the Free Software Foundation; either version 3 of the License, or (at
665 your option) any later version.
667 This program is distributed in the hope that it will be useful, but
668 WITHOUT ANY WARRANTY; without even the implied warranty of
669 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
670 General Public License for more details.
672 You should have received a copy of the GNU General Public License
673 along with this program; if not, see http://www.gnu.org/licenses/.