This documentation was written by
Ronnie Sahlberg,
Amitay Isaacs,
Martin Schwenke
2007
Andrew Tridgell
Ronnie Sahlberg
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.
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.
You should have received a copy of the GNU General Public
License along with this program; if not, see
.
ctdb
1
ctdb
CTDB - clustered TDB database
ctdb
CTDB management utility
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
The node specified by PNN 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 usage information to the screen.
-d --debug=DEBUGLEVEL
Change the debug level for the command. Default is NOTICE.
ADMINISTRATIVE COMMANDS
These are commands used to monitor and administer a CTDB cluster.
pnn
This command displays the PNN of the current node.
status
This command shows the current status of all CTDB nodes based
on information from the queried node.
Note: If 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. Only nodes
that are participating in the VNN map can become lmaster 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 leader 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 leader 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.
Leader
This is the cluster node that is currently designated as the
leader. This node is responsible of monitoring the
consistency of the cluster and to perform the actual
recovery process when required.
Only one node at a time can be the designated leader. Which
node is designated the leader 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)
Leader: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).
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
leader
This command shows the pnn of the node which is currently the leader.
Note: If 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
natgw {leader|list|status}
This command shows different aspects of NAT gateway status.
For an overview of CTDB's NAT gateway functionality please see
the NAT GATEWAY section in
ctdb
7.
leader
Show the PNN and private IP address of the current NAT
gateway leader node.
Example output:
1 192.168.2.201
list
List the private IP addresses of nodes in the current
NAT gateway group, annotating the leader node.
Example output:
192.168.2.200
192.168.2.201 LEADER
192.168.2.202
192.168.2.203
status
List the nodes in the current NAT gateway group and
their status.
Example output:
pnn:0 192.168.2.200 UNHEALTHY (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
response from 0 time=0.000054 sec (3 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 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)
event run|status|script list|script enable|script disable
This command is used to control event daemon and to inspect
status of various events.
The commands below require a component to be specified. In
the current version the only valid component is
legacy.
run TIMEOUT COMPONENT EVENT ARGUMENTS
This command can be used to manually run specified EVENT
in COMPONENT with optional ARGUMENTS. The event will be
allowed to run a maximum of TIMEOUT seconds. If TIMEOUT
is 0, then there is no time limit for running the event.
status COMPONENT EVENT
This command displays the last execution status of the
specified EVENT in COMPONENT.
The command will terminate with the exit status
corresponding to the overall status of event that is
displayed.
The output is the list of event scripts executed.
Each line shows the name, status, duration and start time
for each script. Output from each script is shown.
Example #1
# ctdb event status legacy monitor
00.ctdb OK 0.014 Sat Dec 17 19:39:11 2016
01.reclock OK 0.013 Sat Dec 17 19:39:11 2016
05.system OK 0.029 Sat Dec 17 19:39:11 2016
06.nfs OK 0.014 Sat Dec 17 19:39:11 2016
10.interface OK 0.037 Sat Dec 17 19:39:11 2016
11.natgw OK 0.011 Sat Dec 17 19:39:11 2016
11.routing OK 0.007 Sat Dec 17 19:39:11 2016
13.per_ip_routing OK 0.007 Sat Dec 17 19:39:11 2016
20.multipathd OK 0.007 Sat Dec 17 19:39:11 2016
31.clamd OK 0.007 Sat Dec 17 19:39:11 2016
40.vsftpd OK 0.013 Sat Dec 17 19:39:11 2016
41.httpd OK 0.018 Sat Dec 17 19:39:11 2016
49.winbind OK 0.023 Sat Dec 17 19:39:11 2016
50.samba OK 0.100 Sat Dec 17 19:39:12 2016
60.nfs OK 0.376 Sat Dec 17 19:39:12 2016
70.iscsi OK 0.009 Sat Dec 17 19:39:12 2016
91.lvs OK 0.007 Sat Dec 17 19:39:12 2016
Example #2
# ctdb event status legacy monitor
00.ctdb OK 0.011 Sat Dec 17 19:40:46 2016
01.reclock OK 0.010 Sat Dec 17 19:40:46 2016
05.system OK 0.030 Sat Dec 17 19:40:46 2016
06.nfs OK 0.014 Sat Dec 17 19:40:46 2016
10.interface OK 0.041 Sat Dec 17 19:40:46 2016
11.natgw OK 0.008 Sat Dec 17 19:40:46 2016
11.routing OK 0.007 Sat Dec 17 19:40:46 2016
13.per_ip_routing OK 0.007 Sat Dec 17 19:40:46 2016
20.multipathd OK 0.007 Sat Dec 17 19:40:46 2016
31.clamd OK 0.007 Sat Dec 17 19:40:46 2016
40.vsftpd OK 0.013 Sat Dec 17 19:40:46 2016
41.httpd OK 0.015 Sat Dec 17 19:40:46 2016
49.winbind OK 0.022 Sat Dec 17 19:40:46 2016
50.samba ERROR 0.077 Sat Dec 17 19:40:46 2016
OUTPUT: ERROR: samba tcp port 445 is not responding
script list COMPONENT
List the available event scripts in COMPONENT. Enabled
scripts are flagged with a '*'.
Generally, event scripts are provided by CTDB. However,
local or 3rd party event scripts may also be available.
These are shown in a separate section after those
provided by CTDB.
Example
# ctdb event script list legacy
* 00.ctdb
* 01.reclock
* 05.system
* 06.nfs
* 10.interface
11.natgw
11.routing
13.per_ip_routing
20.multipathd
31.clamd
40.vsftpd
41.httpd
* 49.winbind
* 50.samba
* 60.nfs
70.iscsi
91.lvs
* 02.local
script enable COMPONENT SCRIPT
Enable the specified event SCRIPT in COMPONENT. Only
enabled scripts will be executed when running any event.
script disable COMPONENT SCRIPT
Disable the specified event SCRIPT in COMPONENT. This
will prevent the script from executing when running any
event.
scriptstatus
This is an alias for ctdb event status legacy
EVENT, where EVENT defaults to
monitor.
This command is deprecated. It's provided for backward
compatibility. Use ctdb event status
instead.
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
SeqnumInterval = 1000
ControlTimeout = 60
TraverseTimeout = 20
KeepaliveInterval = 5
KeepaliveLimit = 5
RecoverTimeout = 120
RecoverInterval = 1
ElectionTimeout = 3
TakeoverTimeout = 9
MonitorInterval = 15
TickleUpdateInterval = 20
EventScriptTimeout = 30
MonitorTimeoutCount = 20
RecoveryGracePeriod = 120
RecoveryBanPeriod = 300
DatabaseHashSize = 100001
DatabaseMaxDead = 5
RerecoveryTimeout = 10
EnableBans = 1
NoIPFailback = 0
VerboseMemoryNames = 0
RecdPingTimeout = 60
RecdFailCount = 10
LogLatencyMs = 0
RecLockLatencyMs = 1000
RecoveryDropAllIPs = 120
VacuumInterval = 10
VacuumMaxRunTime = 120
RepackLimit = 10000
VacuumFastPathCount = 60
MaxQueueDropMsg = 1000000
AllowUnhealthyDBRead = 0
StatHistoryInterval = 1
DeferredAttachTO = 120
AllowClientDBAttach = 1
RecoverPDBBySeqNum = 1
DeferredRebalanceOnNodeAdd = 300
FetchCollapse = 1
HopcountMakeSticky = 50
StickyDuration = 600
StickyPindown = 200
NoIPTakeover = 0
DBRecordCountWarn = 100000
DBRecordSizeWarn = 10000000
DBSizeWarn = 100000000
PullDBPreallocation = 10485760
LockProcessesPerDB = 200
RecBufferSizeLimit = 1000000
QueueBufferSize = 1024
IPAllocAlgorithm = 2
getvar NAME
Get the runtime value of a tuneable variable.
Example
# ctdb getvar MonitorInterval
MonitorInterval = 15
setvar NAME VALUE
Set the runtime value of a tuneable variable.
Example
# ctdb setvar MonitorInterval 20
lvs {leader|list|status}
This command shows different aspects of LVS status. For an
overview of CTDB's LVS functionality please see the
LVS section in
ctdb
7.
leader
Shows the PNN of the current LVS leader node.
Example output:
2
list
Lists the currently usable LVS nodes.
Example output:
2 10.0.0.13
3 10.0.0.14
status
List the nodes in the current LVS group and their status.
Example output:
pnn:0 10.0.0.11 UNHEALTHY (THIS NODE)
pnn:1 10.0.0.12 UNHEALTHY
pnn:2 10.0.0.13 OK
pnn:3 10.0.0.14 OK
getcapabilities
This command shows the capabilities of the current node. See
the CAPABILITIES section in
ctdb
7 for more details.
Example output:
LEADER: YES
LMASTER: 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
Current time of statistics : Tue Mar 8 15:18:51 2016
Statistics collected since : (003 21:31:32) Fri Mar 4 17:47:19 2016
num_clients 9
frozen 0
recovering 0
num_recoveries 2
client_packets_sent 8170534
client_packets_recv 7166132
node_packets_sent 16549998
node_packets_recv 5244418
keepalive_packets_sent 201969
keepalive_packets_recv 201969
node
req_call 26
reply_call 0
req_dmaster 9
reply_dmaster 12
reply_error 0
req_message 1339231
req_control 8177506
reply_control 6831284
client
req_call 15
req_message 334809
req_control 6831308
timeouts
call 0
control 0
traverse 0
locks
num_calls 8
num_current 0
num_pending 0
num_failed 0
total_calls 15
pending_calls 0
childwrite_calls 0
pending_childwrite_calls 0
memory_used 394879
max_hop_count 1
total_ro_delegations 0
total_ro_revokes 0
hop_count_buckets: 8 5 0 0 0 0 0 0 0 0 0 0 0 0 0 0
lock_buckets: 0 0 8 0 0 0 0 0 0 0 0 0 0 0 0 0
locks_latency MIN/AVG/MAX 0.010005/0.010418/0.011010 sec out of 8
reclock_ctdbd MIN/AVG/MAX 0.002538/0.002538/0.002538 sec out of 1
reclock_recd MIN/AVG/MAX 0.000000/0.000000/0.000000 sec out of 0
call_latency MIN/AVG/MAX 0.000044/0.002142/0.011702 sec out of 15
childwrite_latency MIN/AVG/MAX 0.000000/0.000000/0.000000 sec out of 0
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
vacuum_latency MIN/AVG/MAX 0.000472/0.002207/15.243570 sec out of 224530
Num Hot Keys: 1
Count:8 Key:ff5bd7cb3ee3822edc1f0000000000000000000000000000
getreclock
Show details of the recovery lock, if any.
Example output:
/clusterfs/.ctdb/recovery.lock
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 :
ERROR 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 ERROR 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 addresses, 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. It should be followed by a ctdb
ipreallocate. 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 flags IPADDR for deletion from a node at runtime.
It should be followed by a ctdb
ipreallocate. If IPADDR is currently hosted by the
node it is being removed from, this ensures that the IP will
first be failed over to another node, if possible, and that it
is then actually 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:
IPAllocAlgorithm != 0
NoIPFailback = 1
shutdown
This command will shutdown a specific CTDB daemon.
setlmasterrole on|off
This command is used to 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"
setleaderrole on|off
This command is used to enable/disable the LEADER capability
for a node at runtime. This capability determines whether or
not a node can be elected leader of the cluster. A node that
does not have the LEADER capability can not be elected
leader. If the current leader has this capability removed then
an election will occur.
Nodes have this capability enabled by default, but it can be
removed via the cluster:leader capability
configuration setting 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 nodes:
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!
On all nodes, edit /usr/local/etc/ctdb/nodes
and add the new nodes at the end of this
file.
Verify that all the nodes have identical
/usr/local/etc/ctdb/nodes files after adding
the new nodes.
Run ctdb reloadnodes to force all nodes
to reload the nodes file.
Use ctdb status on all nodes and verify
that they now show the additional nodes.
Install and configure the new node and bring it online.
Procedure to remove nodes:
To remove nodes 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 nodes from a
cluster unless the cluster is completely healthy!
Shutdown and power off the node to be removed.
On all other nodes, edit the
/usr/local/etc/ctdb/nodes file and
comment out the nodes to be removed.
Do not delete the lines for the deleted
nodes, just comment them out by adding a '#' at
the beginning of the lines.
Run ctdb reloadnodes to force all nodes
to reload the nodes file.
Use ctdb status on all nodes and verify
that the deleted nodes are no longer listed.
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.
This command is currently unable to make changes to the
netmask or interfaces associated with existing addresses.
Such changes must be made in 2 steps by deleting addresses in
question and re-adding then. Unfortunately this will disrupt
connections to the changed addresses.
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. Some database are flagged as REPLICATED,
this means that the data in that database is replicated across all
the nodes. But the data will not remain across reboots. This
type of database is used by CTDB to store it's internal state.
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 automatically. 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:/usr/local/var/lib/ctdb/notify.tdb.0
dbid:0x42fe72c5 name:locking.tdb path:/usr/local/var/lib/ctdb/locking.tdb.0
dbid:0x1421fb78 name:brlock.tdb path:/usr/local/var/lib/ctdb/brlock.tdb.0
dbid:0x17055d90 name:connections.tdb path:/usr/local/var/lib/ctdb/connections.tdb.0
dbid:0xc0bdde6a name:sessionid.tdb path:/usr/local/var/lib/ctdb/sessionid.tdb.0
dbid:0x122224da name:test.tdb path:/usr/local/var/lib/ctdb/test.tdb.0
dbid:0x2672a57f name:idmap2.tdb path:/usr/local/var/lib/ctdb/persistent/idmap2.tdb.0 PERSISTENT
dbid:0xb775fff6 name:secrets.tdb path:/usr/local/var/lib/ctdb/persistent/secrets.tdb.0 PERSISTENT
dbid:0xe98e08b6 name:group_mapping.tdb path:/usr/local/var/lib/ctdb/persistent/group_mapping.tdb.0 PERSISTENT
dbid:0x7bbbd26c name:passdb.tdb path:/usr/local/var/lib/ctdb/persistent/passdb.tdb.0 PERSISTENT
# ctdb getdbmap # example for unhealthy database
Number of databases:1
dbid:0xb775fff6 name:secrets.tdb path:/usr/local/var/lib/ctdb/persistent/secrets.tdb.0 PERSISTENT UNHEALTHY
# ctdb -X getdbmap
|ID|Name|Path|Persistent|Unhealthy|
|0x7bbbd26c|passdb.tdb|/usr/local/var/lib/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.
gratarp IPADDR INTERFACE
Send out a gratuitous ARP for the specified interface through
the specified interface. This command is mainly used by the
ctdb eventscripts.
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
tickle
Read a list of TCP connections, one per line, from standard
input and send a TCP tickle to the source host for each
connection. A connection is specified as:
SRC-IPADDR:SRC-PORT DST-IPADDR:DST-PORT
A single connection can be specified on the command-line
rather than on standard input.
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
occurred 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 [SRVID]
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. When the optional SRVID
argument is specified, the command check if a specific process
exists on the CTDB host and has registered for specified SRVID.
getdbstatus DB
This command displays more details about a database.
Example
# ctdb getdbstatus test.tdb.0
dbid: 0x122224da
name: test.tdb
path: /usr/local/var/lib/ctdb/test.tdb.0
PERSISTENT: no
HEALTH: OK
# ctdb getdbstatus registry.tdb # with a corrupted TDB
dbid: 0xf2a58948
name: registry.tdb
path: /usr/local/var/lib/ctdb/persistent/registry.tdb.0
PERSISTENT: yes
HEALTH: NO-HEALTHY-NODES - ERROR - Backup of corrupted TDB in '/usr/local/var/lib/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 leader 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.
attach DBNAME [persistent|replicated]
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.
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.
SEE ALSO
ctdbd
1,
onnode
1,
ctdb
7,
ctdb-statistics
7,
ctdb-tunables
7,