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ctdb - Online in the Cloud

Run ctdb in OnWorks free hosting provider over Ubuntu Online, Fedora Online, Windows online emulator or MAC OS online emulator

This is the command ctdb that can be run in the OnWorks free hosting provider using one of our multiple free online workstations such as Ubuntu Online, Fedora Online, Windows online emulator or MAC OS online emulator

PROGRAM:

NAME


ctdb - CTDB management utility

SYNOPSIS


ctdb [OPTION...] {COMMAND} [COMMAND-ARGS]

DESCRIPTION


ctdb is a utility to view and manage a CTDB cluster.

The following terms are used when referring to nodes in a cluster:

PNN
Physical Node Number. The physical node number is an integer that describes the node
in the cluster. The first node has physical node number 0. in a cluster.

PNN-LIST
This is either a single PNN, a comma-separate list of PNNs or "all".

Commands that reference a database use the following terms:

DB
This is either a database name, such as locking.tdb or a database ID such as
"0x42fe72c5".

DB-LIST
A space separated list of at least one DB.

OPTIONS


-n PNN-LIST
The nodes specified by PNN-LIST should be queried for the requested information.
Default is to query the daemon running on the local host.

-Y
Produce output in machine readable form for easier parsing by scripts. This uses a
field delimiter of ':'. Not all commands support this option.

-x SEPARATOR
Use SEPARATOR to delimit fields in machine readable output. This implies -Y.

-X
Produce output in machine readable form for easier parsing by scripts. This uses a
field delimiter of '|'. Not all commands support this option.

This is equivalent to "-x|" and avoids some shell quoting issues.

-t TIMEOUT
Indicates that ctdb should wait up to TIMEOUT seconds for a response to most commands
sent to the CTDB daemon. The default is 10 seconds.

-T TIMELIMIT
Indicates that TIMELIMIT is the maximum run time (in seconds) for the ctdb command.
When TIMELIMIT is exceeded the ctdb command will terminate with an error. The default
is 120 seconds.

-? --help
Print some help text to the screen.

--usage
Print useage information to the screen.

-d --debug=DEBUGLEVEL
Change the debug level for the command. Default is NOTICE (2).

--socket=FILENAME
Specify that FILENAME is the name of the Unix domain socket to use when connecting to
the local CTDB daemon. The default is /tmp/ctdb.socket.

ADMINISTRATIVE COMMANDS


These are commands used to monitor and administer a CTDB cluster.

pnn
This command displays the PNN of the current node.

xpnn
This command displays the PNN of the current node without contacting the CTDB daemon. It
parses the nodes file directly, so can produce unexpected output if the nodes file has
been edited but has not been reloaded.

status
This command shows the current status of all CTDB nodes based on information from the
queried node.

Note: If the the queried node is INACTIVE then the status might not be current.

Node status
This includes the number of physical nodes and the status of each node. See ctdb(7)
for information about node states.

Generation
The generation id is a number that indicates the current generation of a cluster
instance. Each time a cluster goes through a reconfiguration or a recovery its
generation id will be changed.

This number does not have any particular meaning other than to keep track of when a
cluster has gone through a recovery. It is a random number that represents the current
instance of a ctdb cluster and its databases. The CTDB daemon uses this number
internally to be able to tell when commands to operate on the cluster and the
databases was issued in a different generation of the cluster, to ensure that commands
that operate on the databases will not survive across a cluster database recovery.
After a recovery, all old outstanding commands will automatically become invalid.

Sometimes this number will be shown as "INVALID". This only means that the ctdbd
daemon has started but it has not yet merged with the cluster through a recovery. All
nodes start with generation "INVALID" and are not assigned a real generation id until
they have successfully been merged with a cluster through a recovery.

Virtual Node Number (VNN) map
Consists of the number of virtual nodes and mapping from virtual node numbers to
physical node numbers. Virtual nodes host CTDB databases. Only nodes that are
participating in the VNN map can become lmaster or dmaster for database records.

Recovery mode
This is the current recovery mode of the cluster. There are two possible modes:

NORMAL - The cluster is fully operational.

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.

Once the recovery master detects an inconsistency, for example a node becomes
disconnected/connected, the recovery daemon will trigger a cluster recovery process,
where all databases are remerged across the cluster. When this process starts, the
recovery master will first "freeze" all databases to prevent applications such as
samba from accessing the databases and it will also mark the recovery mode as
RECOVERY.

When the CTDB daemon starts up, it will start in RECOVERY mode. Once the node has been
merged into a cluster and all databases have been recovered, the node mode will change
into NORMAL mode and the databases will be "thawed", allowing samba to access the
databases again.

Recovery master
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.

Only one node at a time can be the designated recovery master. Which node is
designated the recovery master is decided by an election process in the recovery
daemons running on each node.

Example
# ctdb status
Number of nodes:4
pnn:0 192.168.2.200 OK (THIS NODE)
pnn:1 192.168.2.201 OK
pnn:2 192.168.2.202 OK
pnn:3 192.168.2.203 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

nodestatus [PNN-LIST]
This command is similar to the status command. It displays the "node status" subset of
output. The main differences are:

· The exit code is the bitwise-OR of the flags for each specified node, while ctdb
status exits with 0 if it was able to retrieve status for all nodes.

· ctdb status provides status information for all nodes. ctdb nodestatus defaults to
providing status for only the current node. If PNN-LIST is provided then status is
given for the indicated node(s).

By default, ctdb nodestatus gathers status from the local node. However, if invoked
with "-n all" (or similar) then status is gathered from the given node(s). In
particular ctdb nodestatus all and ctdb nodestatus -n all will produce different
output. It is possible to provide 2 different nodespecs (with and without "-n") but
the output is usually confusing!

A common invocation in scripts is ctdb nodestatus all to check whether all nodes in a
cluster are healthy.

Example
# ctdb nodestatus
pnn:0 10.0.0.30 OK (THIS NODE)

# ctdb nodestatus all
Number of nodes:2
pnn:0 10.0.0.30 OK (THIS NODE)
pnn:1 10.0.0.31 OK

recmaster
This command shows the pnn of the node which is currently the recmaster.

Note: If the the queried node is INACTIVE then the status might not be current.

uptime
This command shows the uptime for the ctdb daemon. When the last recovery or ip-failover
completed and how long it took. If the "duration" is shown as a negative number, this
indicates that there is a recovery/failover in progress and it started that many seconds
ago.

Example
# ctdb uptime
Current time of node : Thu Oct 29 10:38:54 2009
Ctdbd start time : (000 16:54:28) Wed Oct 28 17:44:26 2009
Time of last recovery/failover: (000 16:53:31) Wed Oct 28 17:45:23 2009
Duration of last recovery/failover: 2.248552 seconds

listnodes
This command shows lists the ip addresses of all the nodes in the cluster.

Example
# ctdb listnodes
192.168.2.200
192.168.2.201
192.168.2.202
192.168.2.203

natgwlist
Show the current NAT gateway master and the status of all nodes in the current NAT gateway
group. See the NAT GATEWAY section in ctdb(7) for more details.

Example
# ctdb natgwlist
0 192.168.2.200
Number of nodes:4
pnn:0 192.168.2.200 OK (THIS NODE)
pnn:1 192.168.2.201 OK
pnn:2 192.168.2.202 OK
pnn:3 192.168.2.203 OK

ping
This command will "ping" specified CTDB nodes in the cluster to verify that they are
running.

Example
# ctdb ping -n all
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)

ifaces
This command will display the list of network interfaces, which could host public
addresses, along with their status.

Example
# ctdb ifaces
Interfaces on node 0
name:eth5 link:up references:2
name:eth4 link:down references:0
name:eth3 link:up references:1
name:eth2 link:up references:1

# ctdb -X ifaces
|Name|LinkStatus|References|
|eth5|1|2|
|eth4|0|0|
|eth3|1|1|
|eth2|1|1|

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. By default this command will ONLY
show those public addresses that are known to the node itself. To see the full list of all
public ips across the cluster you must use "ctdb ip -n all".

Example
# ctdb ip -v
Public IPs on node 0
172.31.91.82 node[1] active[] available[eth2,eth3] configured[eth2,eth3]
172.31.91.83 node[0] active[eth3] available[eth2,eth3] configured[eth2,eth3]
172.31.91.84 node[1] active[] available[eth2,eth3] configured[eth2,eth3]
172.31.91.85 node[0] active[eth2] available[eth2,eth3] configured[eth2,eth3]
172.31.92.82 node[1] active[] available[eth5] configured[eth4,eth5]
172.31.92.83 node[0] active[eth5] available[eth5] configured[eth4,eth5]
172.31.92.84 node[1] active[] available[eth5] configured[eth4,eth5]
172.31.92.85 node[0] active[eth5] available[eth5] configured[eth4,eth5]

# ctdb -X ip -v
|Public IP|Node|ActiveInterface|AvailableInterfaces|ConfiguredInterfaces|
|172.31.91.82|1||eth2,eth3|eth2,eth3|
|172.31.91.83|0|eth3|eth2,eth3|eth2,eth3|
|172.31.91.84|1||eth2,eth3|eth2,eth3|
|172.31.91.85|0|eth2|eth2,eth3|eth2,eth3|
|172.31.92.82|1||eth5|eth4,eth5|
|172.31.92.83|0|eth5|eth5|eth4,eth5|
|172.31.92.84|1||eth5|eth4,eth5|
|172.31.92.85|0|eth5|eth5|eth4,eth5|

ipinfo IP
This command will display details about the specified public addresses.

Example
# ctdb ipinfo 172.31.92.85
Public IP[172.31.92.85] info on node 0
IP:172.31.92.85
CurrentNode:0
NumInterfaces:2
Interface[1]: Name:eth4 Link:down References:0
Interface[2]: Name:eth5 Link:up References:2 (active)

scriptstatus
This command displays which scripts where run in the previous monitoring cycle and the
result of each script. If a script failed with an error, causing the node to become
unhealthy, the output from that script is also shown.

Example
# ctdb scriptstatus
7 scripts were executed last monitoring cycle
00.ctdb Status:OK Duration:0.056 Tue Mar 24 18:56:57 2009
10.interface Status:OK Duration:0.077 Tue Mar 24 18:56:57 2009
11.natgw Status:OK Duration:0.039 Tue Mar 24 18:56:57 2009
20.multipathd Status:OK Duration:0.038 Tue Mar 24 18:56:57 2009
31.clamd Status:DISABLED
40.vsftpd Status:OK Duration:0.045 Tue Mar 24 18:56:57 2009
41.httpd Status:OK Duration:0.039 Tue Mar 24 18:56:57 2009
50.samba Status:ERROR Duration:0.082 Tue Mar 24 18:56:57 2009
OUTPUT:ERROR: Samba tcp port 445 is not responding

disablescript SCRIPT
This command is used to disable an eventscript.

This will take effect the next time the eventscripts are being executed so it can take a
short while until this is reflected in 'scriptstatus'.

enablescript SCRIPT
This command is used to enable an eventscript.

This will take effect the next time the eventscripts are being executed so it can take a
short while until this is reflected in 'scriptstatus'.

listvars
List all tuneable variables, except the values of the obsolete tunables like
VacuumMinInterval. The obsolete tunables can be retrieved only explicitly with the "ctdb
getvar" command.

Example
# ctdb listvars
MaxRedirectCount = 3
SeqnumInterval = 1000
ControlTimeout = 60
TraverseTimeout = 20
KeepaliveInterval = 5
KeepaliveLimit = 5
RecoverTimeout = 20
RecoverInterval = 1
ElectionTimeout = 3
TakeoverTimeout = 9
MonitorInterval = 15
TickleUpdateInterval = 20
EventScriptTimeout = 30
EventScriptTimeoutCount = 1
RecoveryGracePeriod = 120
RecoveryBanPeriod = 300
DatabaseHashSize = 100001
DatabaseMaxDead = 5
RerecoveryTimeout = 10
EnableBans = 1
DeterministicIPs = 0
LCP2PublicIPs = 1
ReclockPingPeriod = 60
NoIPFailback = 0
DisableIPFailover = 0
VerboseMemoryNames = 0
RecdPingTimeout = 60
RecdFailCount = 10
LogLatencyMs = 0
RecLockLatencyMs = 1000
RecoveryDropAllIPs = 120
VacuumInterval = 10
VacuumMaxRunTime = 30
RepackLimit = 10000
VacuumLimit = 5000
VacuumFastPathCount = 60
MaxQueueDropMsg = 1000000
UseStatusEvents = 0
AllowUnhealthyDBRead = 0
StatHistoryInterval = 1
DeferredAttachTO = 120
AllowClientDBAttach = 1
RecoverPDBBySeqNum = 0

getvar NAME
Get the runtime value of a tuneable variable.

Example
# ctdb getvar MaxRedirectCount
MaxRedirectCount = 3

setvar NAME VALUE
Set the runtime value of a tuneable variable.

Example: ctdb setvar MaxRedirectCount 5

lvsmaster
This command shows which node is currently the LVSMASTER. The LVSMASTER is the node in the
cluster which drives the LVS system and which receives all incoming traffic from clients.

LVS is the mode where the entire CTDB/Samba cluster uses a single ip address for the
entire cluster. In this mode all clients connect to one specific node which will then
multiplex/loadbalance the clients evenly onto the other nodes in the cluster. This is an
alternative to using public ip addresses. See the manpage for ctdbd for more information
about LVS.

lvs
This command shows which nodes in the cluster are currently active in the LVS
configuration. I.e. which nodes we are currently loadbalancing the single ip address
across.

LVS will by default only loadbalance across those nodes that are both LVS capable and also
HEALTHY. Except if all nodes are UNHEALTHY in which case LVS will loadbalance across all
UNHEALTHY nodes as well. LVS will never use nodes that are DISCONNECTED, STOPPED, BANNED
or DISABLED.

Example output:

2:10.0.0.13
3:10.0.0.14

getcapabilities
This command shows the capabilities of the current node. See the CAPABILITIES section in
ctdb(7) for more details.

Example output:

RECMASTER: YES
LMASTER: YES
LVS: NO
NATGW: YES

statistics
Collect statistics from the CTDB daemon about how many calls it has served. Information
about various fields in statistics can be found in ctdb-statistics(7).

Example
# ctdb statistics
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

dbstatistics DB
Display statistics about the database DB. Information about various fields in dbstatistics
can be found in ctdb-statistics(7).

Example
# ctdb dbstatistics locking.tdb
DB Statistics: locking.tdb
ro_delegations 0
ro_revokes 0
locks
total 14356
failed 0
current 0
pending 0
hop_count_buckets: 28087 2 1 0 0 0 0 0 0 0 0 0 0 0 0 0
lock_buckets: 0 14188 38 76 32 19 3 0 0 0 0 0 0 0 0 0
locks_latency MIN/AVG/MAX 0.001066/0.012686/4.202292 sec out of 14356
Num Hot Keys: 1
Count:8 Key:ff5bd7cb3ee3822edc1f0000000000000000000000000000

getreclock
Show the name of the recovery lock file, if any.

Example output:

Reclock file:/clusterfs/.ctdb/recovery.lock

setreclock [FILE]
FILE specifies the name of the recovery lock file. If the recovery lock file is changed at
run-time then this will cause a recovery, which in turn causes the recovery lock to be
retaken.

If no FILE is specified then a recovery lock file will no longer be used.

This command only affects the run-time setting of a single CTDB node. This setting must be
changed on all nodes simultaneously by specifying -n all (or similar). For information
about configuring the recovery lock file please see the CTDB_RECOVERY_LOCK entry in
ctdbd.conf(5) and the --reclock entry in ctdbd(1). For information about the recovery lock
please see the RECOVERY LOCK section in ctdb(7).

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

The debug levels are mapped to the corresponding syslog levels. When a debug level is set,
only those messages at that level and higher levels will be printed.

The list of debug levels from highest to lowest are :

ERR WARNING NOTICE INFO DEBUG

setdebug DEBUGLEVEL
Set the debug level of a node. This controls what information will be logged.

The debuglevel is one of ERR WARNING NOTICE INFO DEBUG

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.

stop
This command is used to administratively STOP a node in the cluster. A STOPPED node is
connected to the cluster but will not host any public ip addresse, nor does it participate
in the VNNMAP. The difference between a DISABLED node and a STOPPED node is that a STOPPED
node does not host any parts of the database which means that a recovery is required to
stop/continue nodes.

continue
Re-start a node that has been administratively stopped.

addip IPADDR/mask IFACE
This command is used to add a new public ip to a node during runtime. This allows public
addresses to be added to a cluster without having to restart the ctdb daemons.

Note that this only updates the runtime instance of ctdb. Any changes will be lost next
time ctdb is restarted and the public addresses file is re-read. If you want this change
to be permanent you must also update the public addresses file manually.

delip IPADDR
This command is used to remove a public ip from a node during runtime. If this public ip
is currently hosted by the node it being removed from, the ip will first be failed over to
another node, if possible, before it is removed.

Note that this only updates the runtime instance of ctdb. Any changes will be lost next
time ctdb is restarted and the public addresses file is re-read. If you want this change
to be permanent you must also update the public addresses file manually.

moveip IPADDR PNN
This command can be used to manually fail a public ip address to a specific node.

In order to manually override the "automatic" distribution of public ip addresses that
ctdb normally provides, this command only works when you have changed the tunables for the
daemon to:

DeterministicIPs = 0

NoIPFailback = 1

shutdown
This command will shutdown a specific CTDB daemon.

setlmasterrole on|off
This command is used ot enable/disable the LMASTER capability for a node at runtime. This
capability determines whether or not a node can be used as an LMASTER for records in the
database. A node that does not have the LMASTER capability will not show up in the vnnmap.

Nodes will by default have this capability, but it can be stripped off nodes by the
setting in the sysconfig file or by using this command.

Once this setting has been enabled/disabled, you need to perform a recovery for it to take
effect.

See also "ctdb getcapabilities"

setrecmasterrole on|off
This command is used ot enable/disable the RECMASTER capability for a node at runtime.
This capability determines whether or not a node can be used as an RECMASTER for the
cluster. A node that does not have the RECMASTER capability can not win a recmaster
election. A node that already is the recmaster for the cluster when the capability is
stripped off the node will remain the recmaster until the next cluster election.

Nodes will by default have this capability, but it can be stripped off nodes by the
setting in the sysconfig file or by using this command.

See also "ctdb getcapabilities"

reloadnodes
This command is used when adding new nodes, or removing existing nodes from an existing
cluster.

Procedure to add a node:

1, To expand an existing cluster, first ensure with 'ctdb status' that all nodes are up
and running and that they are all healthy. Do not try to expand a cluster unless it is
completely healthy!

2, On all nodes, edit /etc/ctdb/nodes and add the new node as the last entry to the file.
The new node MUST be added to the end of this file!

3, Verify that all the nodes have identical /etc/ctdb/nodes files after you edited them
and added the new node!

4, Run 'ctdb reloadnodes' to force all nodes to reload the nodesfile.

5, Use 'ctdb status' on all nodes and verify that they now show the additional node.

6, Install and configure the new node and bring it online.

Procedure to remove a node:

1, To remove a node from an existing cluster, first ensure with 'ctdb status' that all
nodes, except the node to be deleted, are up and running and that they are all healthy. Do
not try to remove a node from a cluster unless the cluster is completely healthy!

2, Shutdown and poweroff the node to be removed.

3, On all other nodes, edit the /etc/ctdb/nodes file and comment out the node to be
removed. Do not delete the line for that node, just comment it out by adding a '#' at the
beginning of the line.

4, Run 'ctdb reloadnodes' to force all nodes to reload the nodesfile.

5, Use 'ctdb status' on all nodes and verify that the deleted node no longer shows up in
the list..

reloadips [PNN-LIST]
This command reloads the public addresses configuration file on the specified nodes. When
it completes addresses will be reconfigured and reassigned across the cluster as
necessary.

getdbmap
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.

If a PERSISTENT database is not in a healthy state the database is flagged as UNHEALTHY.
If there's at least one completely healthy node running in the cluster, it's possible that
the content is restored by a recovery run automaticly. Otherwise an administrator needs to
analyze the problem.

See also "ctdb getdbstatus", "ctdb backupdb", "ctdb restoredb", "ctdb dumpbackup", "ctdb
wipedb", "ctdb setvar AllowUnhealthyDBRead 1" and (if samba or tdb-utils are installed)
"tdbtool check".

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.

Example
# ctdb getdbmap
Number of databases:10
dbid:0x435d3410 name:notify.tdb path:/var/ctdb/notify.tdb.0
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
dbid:0x122224da name:test.tdb path:/var/ctdb/test.tdb.0
dbid:0x2672a57f name:idmap2.tdb path:/var/ctdb/persistent/idmap2.tdb.0 PERSISTENT
dbid:0xb775fff6 name:secrets.tdb path:/var/ctdb/persistent/secrets.tdb.0 PERSISTENT
dbid:0xe98e08b6 name:group_mapping.tdb path:/var/ctdb/persistent/group_mapping.tdb.0 PERSISTENT
dbid:0x7bbbd26c name:passdb.tdb path:/var/ctdb/persistent/passdb.tdb.0 PERSISTENT

# ctdb getdbmap # example for unhealthy database
Number of databases:1
dbid:0xb775fff6 name:secrets.tdb path:/var/ctdb/persistent/secrets.tdb.0 PERSISTENT UNHEALTHY

# ctdb -X getdbmap
|ID|Name|Path|Persistent|Unhealthy|
|0x7bbbd26c|passdb.tdb|/var/ctdb/persistent/passdb.tdb.0|1|0|

backupdb DB FILE
Copy the contents of database DB to FILE. FILE can later be read back using restoredb.
This is mainly useful for backing up persistent databases such as secrets.tdb and similar.

restoredb FILE [DB]
This command restores a persistent database that was previously backed up using backupdb.
By default the data will be restored back into the same database as it was created from.
By specifying dbname you can restore the data into a different database.

setdbreadonly DB
This command will enable the read-only record support for a database. This is an
experimental feature to improve performance for contended records primarily in locking.tdb
and brlock.tdb. When enabling this feature you must set it on all nodes in the cluster.

setdbsticky DB
This command will enable the sticky record support for the specified database. This is an
experimental feature to improve performance for contended records primarily in locking.tdb
and brlock.tdb. When enabling this feature you must set it on all nodes in the cluster.

INTERNAL COMMANDS


Internal commands are used by CTDB's scripts and are not required for managing a CTDB
cluster. Their parameters and behaviour are subject to change.

gettickles IPADDR
Show TCP connections that are registered with CTDB to be "tickled" if there is a failover.

gratiousarp IPADDR INTERFACE
Send out a gratious ARP for the specified interface through the specified interface. This
command is mainly used by the ctdb eventscripts.

killtcp
Read a list of TCP connections, one per line, from standard input and terminate each
connection. A connection is specified as:

SRC-IPADDR:SRC-PORT DST-IPADDR:DST-PORT

Each connection is terminated by issuing a TCP RST to the SRC-IPADDR:SRC-PORT endpoint.

A single connection can be specified on the command-line rather than on standard input.

pdelete DB KEY
Delete KEY from DB.

pfetch DB KEY
Print the value associated with KEY in DB.

pstore DB KEY FILE
Store KEY in DB with contents of FILE as the associated value.

ptrans DB [FILE]
Read a list of key-value pairs, one per line from FILE, and store them in DB using a
single transaction. An empty value is equivalent to deleting the given key.

The key and value should be separated by spaces or tabs. Each key/value should be a
printable string enclosed in double-quotes.

runstate [setup|first_recovery|startup|running]
Print the runstate of the specified node. Runstates are used to serialise important state
transitions in CTDB, particularly during startup.

If one or more optional runstate arguments are specified then the node must be in one of
these runstates for the command to succeed.

Example
# ctdb runstate
RUNNING

setifacelink IFACE up|down
Set the internal state of network interface IFACE. This is typically used in the
10.interface script in the "monitor" event.

Example: ctdb setifacelink eth0 up

setnatgwstate on|off
Enable or disable the NAT gateway master capability on a node.

tickle SRC-IPADDR:SRC-PORT DST-IPADDR:DST-PORT
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.

version
Display the CTDB version.

DEBUGGING COMMANDS


These commands are primarily used for CTDB development and testing and should not be used
for normal administration.

OPTIONS
--print-emptyrecords
This enables printing of empty records when dumping databases with the catdb, cattbd
and dumpdbbackup commands. Records with empty data segment are considered deleted by
ctdb and cleaned by the vacuuming mechanism, so this switch can come in handy for
debugging the vacuuming behaviour.

--print-datasize
This lets database dumps (catdb, cattdb, dumpdbbackup) print the size of the record
data instead of dumping the data contents.

--print-lmaster
This lets catdb print the lmaster for each record.

--print-hash
This lets database dumps (catdb, cattdb, dumpdbbackup) print the hash for each record.

--print-recordflags
This lets catdb and dumpdbbackup print the record flags for each record. Note that
cattdb always prints the flags.

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.

getdbstatus DB
This command displays more details about a database.

Example
# ctdb getdbstatus test.tdb.0
dbid: 0x122224da
name: test.tdb
path: /var/ctdb/test.tdb.0
PERSISTENT: no
HEALTH: OK

# ctdb getdbstatus registry.tdb # with a corrupted TDB
dbid: 0xf2a58948
name: registry.tdb
path: /var/ctdb/persistent/registry.tdb.0
PERSISTENT: yes
HEALTH: NO-HEALTHY-NODES - ERROR - Backup of corrupted TDB in '/var/ctdb/persistent/registry.tdb.0.corrupted.20091208091949.0Z'

catdb DB
Print a dump of the clustered TDB database DB.

cattdb DB
Print a dump of the contents of the local TDB database DB.

dumpdbbackup FILE
Print a dump of the contents from database backup FILE, similar to catdb.

wipedb DB
Remove all contents of database DB.

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

ipreallocate, sync
This command will force the recovery master to perform a full ip reallocation process and
redistribute all ip addresses. This is useful to "reset" the allocations back to its
default state if they have been changed using the "moveip" command. While a "recover" will
also perform this reallocation, a recovery is much more hevyweight since it will also
rebuild all the databases.

getmonmode
This command returns the monutoring mode of a node. The monitoring mode is either ACTIVE
or DISABLED. Normally a node will continuously 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 explicitly 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 [persistent]
Create a new CTDB database called DBNAME and attach to it on all nodes.

detach DB-LIST
Detach specified non-persistent database(s) from the cluster. This command will disconnect
specified database(s) on all nodes in the cluster. This command should only be used when
none of the specified database(s) are in use.

All nodes should be active and tunable AllowClientDBAccess should be disabled on all nodes
before detaching databases.

dumpmemory
This is a debugging command. This command will make the ctdb daemon to write a fill memory
allocation map to standard output.

rddumpmemory
This is a debugging command. This command will dump the talloc memory allocation tree for
the recovery daemon to standard output.

thaw
Thaw a previously frozen node.

eventscript ARGUMENTS
This is a debugging command. This command can be used to manually invoke and run the
eventscritps with arbitrary arguments.

ban BANTIME
Administratively ban a node for BANTIME seconds. The node will be unbanned after BANTIME
seconds have elapsed.

A banned node does not participate in the cluster. It does not host any records for the
clustered TDB and does not host any public IP addresses.

Nodes are automatically banned if they misbehave. For example, a node may be banned if it
causes too many cluster recoveries.

To administratively exclude a node from a cluster use the stop command.

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

rebalancenode [PNN-LIST]
This command marks the given nodes as rebalance targets in the LCP2 IP allocation
algorithm. The reloadips command will do this as necessary so this command should not be
needed.

check_srvids SRVID ...
This command checks whether a set of srvid message ports are registered on the node or
not. The command takes a list of values to check.

Example
# ctdb check_srvids 1 2 3 14765
Server id 0:1 does not exist
Server id 0:2 does not exist
Server id 0:3 does not exist
Server id 0:14765 exists

Use ctdb online using onworks.net services


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