status

This command shows the current status of the ctdb node.

Example: ctdb status

Example output:

Number of nodes:4
vnn:0 11.1.2.200       OK (THIS NODE)
vnn:1 11.1.2.201       OK
vnn:2 11.1.2.202       OK
vnn:3 11.1.2.203       OK
Generation:1362079228
Size:4
hash:0 lmaster:0
hash:1 lmaster:1
hash:2 lmaster:2
hash:3 lmaster:3
Recovery mode:NORMAL (0)
Recovery master:0
      

ping

This command will "ping" all CTDB daemons in the cluster to verify that they are processing commands correctly.

Example: ctdb ping

Example output:

response from 0 time=0.000054 sec  (3 clients)
response from 1 time=0.000144 sec  (2 clients)
response from 2 time=0.000105 sec  (2 clients)
response from 3 time=0.000114 sec  (2 clients)
      

ip

This command will display the list of public addresses that are provided by the cluster and which physical node is currently serving this ip.

Example: ctdb ip

Example output:

Number of nodes:4
12.1.1.1         0
12.1.1.2         1
12.1.1.3         2
12.1.1.4         3
      

getvar <name>

Get the runtime value of a tuneable variable.

Example: ctdb getvar MaxRedirectCount

Example output:

MaxRedirectCount    = 3
      

setvar <name> <value>

Set the runtime value of a tuneable variable.

Example: ctdb setvar MaxRedirectCount 5

listvars

List all tuneable variables.

Example: ctdb listvars

Example output:

MaxRedirectCount    = 5
SeqnumFrequency     = 1
ControlTimeout      = 60
TraverseTimeout     = 20
KeepaliveInterval   = 2
KeepaliveLimit      = 3
MaxLACount          = 7
RecoverTimeout      = 5
RecoverInterval     = 1
ElectionTimeout     = 3
TakeoverTimeout     = 5
MonitorInterval     = 15
EventScriptTimeout  = 20
RecoveryGracePeriod = 60
RecoveryBanPeriod   = 300
      

statistics

Collect statistics from the CTDB daemon about how many calls it has served.

Example: ctdb statistics

Example output:

CTDB version 1
 num_clients                        3
 frozen                             0
 recovering                         0
 client_packets_sent           360489
 client_packets_recv           360466
 node_packets_sent             480931
 node_packets_recv             240120
 keepalive_packets_sent             4
 keepalive_packets_recv             3
 node
     req_call                       2
     reply_call                     2
     req_dmaster                    0
     reply_dmaster                  0
     reply_error                    0
     req_message                   42
     req_control               120408
     reply_control             360439
 client
     req_call                       2
     req_message                   24
     req_control               360440
 timeouts
     call                           0
     control                        0
     traverse                       0
 total_calls                        2
 pending_calls                      0
 lockwait_calls                     0
 pending_lockwait_calls             0
 memory_used                     5040
 max_hop_count                      0
 max_call_latency                   4.948321 sec
 max_lockwait_latency               0.000000 sec
      

statisticsreset

This command is used to clear all statistics counters in a node.

Example: ctdb statisticsreset

getdebug

Get the current debug level for the node. the debug level controls what information is written to the log file.

setdebug <debuglevel>

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.

getpid

This command will return the process id of the ctdb daemon.

disable

This command is used to administratively disable a node in the cluster. A disabled node will still participate in the cluster and host clustered TDB records but its public ip address has been taken over by a different node and it no longer hosts any services.

enable

Re-enable a node that has been administratively disabled.

ban <bantime|0>

Administratively ban a node for bantime seconds. A bantime of 0 means that the node should be permanently banned.

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.

Nodes are automatically banned if they are the cause of too many cluster recoveries.

unban

This command is used to unban a node that has either been administratively banned using the ban command or has been automatically banned by the recovery daemon.

shutdown

This command will shutdown a specific CTDB daemon.

recover

This command will trigger the recovery daemon to do a cluster recovery.

killtcp <srcip:port> <dstip:port>

This command will kill the specified TCP connection by issuing a TCP RST to the srcip:port endpoint.

tickle <srcip:port> <dstip:port>

This command will will send a TCP tickle to the source host for the specified TCP connection. A TCP tickle is a TCP ACK packet with an invalid sequence and acknowledge number and will when received by the source host result in it sending an immediate correct ACK back to the other end.

TCP tickles are useful to "tickle" clients after a IP failover has occured since this will make the client immediately recognize the TCP connection has been disrupted and that the client will need to reestablish. This greatly speeds up the time it takes for a client to detect and reestablish after an IP failover in the ctdb cluster.

process-exists <pid>

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.

getdbmap

This command lists all clustered TDB databases that the CTDB daemon has attahced to.

Example: ctdb getdbmap

Example output:

Number of databases:4
dbid:0x42fe72c5 name:locking.tdb path:/var/ctdb/locking.tdb.0
dbid:0x1421fb78 name:brlock.tdb path:/var/ctdb/brlock.tdb.0
dbid:0x17055d90 name:connections.tdb path:/var/ctdb/connections.tdb.0
dbid:0xc0bdde6a name:sessionid.tdb path:/var/ctdb/sessionid.tdb.0
      

catdb <dbname>

This command will dump a clustered TDB database to the screen. This is a debugging command.

getmonmode

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.

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.

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.

setmonmode <0|1>

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.

attach <dbname>

This is a debugging command. This command will make the CTDB daemon create a new CTDB database and attach to it.

dumpmemory

This is a debugging command. This command will make the ctdb daemon to write a fill memory allocation map to the log file.

freeze

This command will lock all the local TDB databases causing clients that are accessing these TDBs such as samba3 to block until the databases are thawed.

This is primarily used by the recovery daemon to stop all samba daemons from accessing any databases while the database is recovered and rebuilt.

thaw

Thaw a previously frozen node.