From 08a79857935fa60c124a62cadc4ef4800b912134 Mon Sep 17 00:00:00 2001 From: Ronnie Sahlberg Date: Thu, 10 Jan 2008 11:06:10 +1100 Subject: add documentation for the vacuum and repack commands. document the -T option to ctdb (This used to be ctdb commit fa5abbddaedc1c330f03cbacaa2ab4a76b0945ff) --- ctdb/doc/ctdb.1 | 39 ++++++++++++++++-- ctdb/doc/ctdb.1.html | 114 +++++++++++++++++++++++++++++++++------------------ ctdb/doc/ctdb.1.xml | 71 +++++++++++++++++++++++++++++++- 3 files changed, 179 insertions(+), 45 deletions(-) (limited to 'ctdb') diff --git a/ctdb/doc/ctdb.1 b/ctdb/doc/ctdb.1 index f20780c3b1..49738255ca 100644 --- a/ctdb/doc/ctdb.1 +++ b/ctdb/doc/ctdb.1 @@ -1,11 +1,11 @@ .\" Title: ctdb .\" Author: .\" Generator: DocBook XSL Stylesheets v1.71.0 -.\" Date: 09/14/2007 +.\" Date: 01/10/2008 .\" Manual: .\" Source: .\" -.TH "CTDB" "1" "09/14/2007" "" "" +.TH "CTDB" "1" "01/10/2008" "" "" .\" disable hyphenation .nh .\" disable justification (adjust text to left margin only) @@ -16,7 +16,7 @@ ctdb \- clustered tdb database management utility .HP 29 \fBctdb [ OPTIONS ] COMMAND ...\fR .HP 5 -\fBctdb\fR [\-n\ ] [\-Y] [\-t\ ] [\-?\ \-\-help] [\-\-usage] [\-d\ \-\-debug=] [\-\-socket=] +\fBctdb\fR [\-n\ ] [\-Y] [\-t\ ] [\-T\ ] [\-?\ \-\-help] [\-\-usage] [\-d\ \-\-debug=] [\-\-socket=] .SH "DESCRIPTION" .PP ctdb is a utility to view and manage a ctdb cluster. @@ -36,7 +36,12 @@ Produce output in machine readable form for easier parsing by scripts. Not all c .PP \-t .RS 3n -How long should ctdb wait for a command to complete before timing out. Default is 3 seconds. +How long should ctdb wait for the local ctdb daemon to respond to a command before timing out. Default is 3 seconds. +.RE +.PP +\-T +.RS 3n +A limit on how long the ctdb command will run for before it will be aborted. When this timelimit has been exceeded the ctdb command will terminate. .RE .PP \-? \-\-help @@ -327,6 +332,32 @@ This command will kill the specified TCP connection by issuing a TCP RST to the 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. .PP 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. +.SS "repack [max_freelist]" +.PP +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. This command is used to defragment a TDB database and pruning the freelist. +.PP +If [max_freelist] is specified, then a database will only be repacked if it has more than this number of entries in the freelist. +.PP +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. +.PP +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. +.PP +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. +.PP +Example: ctdb repack 1000 +.PP +By default, this operation is issued from the 00.ctdb event script every 5 minutes. +.SS "vacuum [max_records]" +.PP +Over time CTDB databases will fill up with empty deleted records which will lead to a progressive slow down of CTDB database access. This command is used to prune all databases and delete all empty records from the cluster. +.PP +By default, vacuum will delete all empty records from all databases. If [max_records] is specified, only databases with that many or more empty records will be pruned. +.PP +Vacuum only deletes those records where the local node is the lmaster. To delete all records from the entire cluster you need to run a vacuum from each node. This command is not disruptive. Samba is unaffected and will still be able to read/write records normally while the database is being vacuumed. +.PP +Example: ctdb vacuum +.PP +By default, this operation is issued from the 00.ctdb event script every 5 minutes. .SH "DEBUGGING COMMANDS" .PP These commands are primarily used for CTDB development and testing and should not be used for normal administration. diff --git a/ctdb/doc/ctdb.1.html b/ctdb/doc/ctdb.1.html index 4e0d056815..5d9d963db9 100644 --- a/ctdb/doc/ctdb.1.html +++ b/ctdb/doc/ctdb.1.html @@ -1,6 +1,6 @@ -ctdb

Name

ctdb — clustered tdb database management utility

Synopsis

ctdb [ OPTIONS ] COMMAND ...

ctdb [-n <node>] [-Y] [-t <timeout>] [-? --help] [--usage] [-d --debug=<INTEGER>] [--socket=<filename>]

DESCRIPTION

+ctdb

Name

ctdb — clustered tdb database management utility

Synopsis

ctdb [ OPTIONS ] COMMAND ...

ctdb [-n <node>] [-Y] [-t <timeout>] [-T <timelimit>] [-? --help] [--usage] [-d --debug=<INTEGER>] [--socket=<filename>]

DESCRIPTION

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

OPTIONS

-n <pnn>

+

OPTIONS

-n <pnn>

This specifies the physical node number on which to execute the command. Default is to run the command on the deamon running on the local host. @@ -10,7 +10,11 @@

-Y

Produce output in machine readable form for easier parsing by scripts. Not all commands support this option.

-t <timeout>

- How long should ctdb wait for a command to complete before timing out. Default is 3 seconds. + How long should ctdb wait for the local ctdb daemon to respond to a command before timing out. Default is 3 seconds. +

-T <timelimit>

+ A limit on how long the ctdb command will run for before it will + be aborted. When this timelimit has been exceeded the ctdb command will + terminate.

-? --help

Print some help text to the screen.

--usage

@@ -24,11 +28,11 @@ You only need to specify this parameter if you run multiple ctdb daemons on the same physical host and thus can not use the default name for the domain socket. -

Administrative Commands

+

Administrative Commands

These are commands used to monitor and administrate a CTDB cluster. -

status

+

status

This command shows the current status of the ctdb node. -

node status

+

node status

Node status reflects the current status of the node. There are four possible states:

OK - This node is fully functional. @@ -40,20 +44,20 @@ 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.

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. -

generation

+

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. -

VNNMAP

+

VNNMAP

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. Only nodes that are participating in the vnnmap can become lmaster or dmaster for a database record. -

Recovery mode

+

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. -

Recovery master

+

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.

Example: ctdb status @@ -71,7 +75,7 @@ hash:2 lmaster:2 hash:3 lmaster:3 Recovery mode:NORMAL (0) Recovery master:0 -

ping

+

ping

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

Example: ctdb ping @@ -82,7 +86,7 @@ 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

+

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 @@ -94,7 +98,7 @@ Number of addresses:4 12.1.1.2 1 12.1.1.3 2 12.1.1.4 3 -

getvar <name>

+

getvar <name>

Get the runtime value of a tuneable variable.

Example: ctdb getvar MaxRedirectCount @@ -102,11 +106,11 @@ Number of addresses:4 Example output:

 MaxRedirectCount    = 3
-      

setvar <name> <value>

+

setvar <name> <value>

Set the runtime value of a tuneable variable.

Example: ctdb setvar MaxRedirectCount 5 -

listvars

+

listvars

List all tuneable variables.

Example: ctdb listvars @@ -128,7 +132,7 @@ MonitorInterval = 15 EventScriptTimeout = 20 RecoveryGracePeriod = 60 RecoveryBanPeriod = 300 -

statistics

+

statistics

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

Example: ctdb statistics @@ -170,43 +174,43 @@ CTDB version 1 max_hop_count 0 max_call_latency 4.948321 sec max_lockwait_latency 0.000000 sec -

statisticsreset

+

statisticsreset

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

Example: ctdb statisticsreset -

getdebug

+

getdebug

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

setdebug <debuglevel>

+

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

+

getpid

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

disable

+

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

+

enable

Re-enable a node that has been administratively disabled. -

ban <bantime|0>

+

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

+

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

+

shutdown

This command will shutdown a specific CTDB daemon. -

recover

+

recover

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

killtcp <srcip:port> <dstip:port>

+

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>

+

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 @@ -218,12 +222,42 @@ CTDB version 1 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. -

Debugging Commands

+

repack [max_freelist]

+ 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. + This command is used to defragment a TDB database and pruning the freelist. +

+ If [max_freelist] is specified, then a database will only be repacked if it has more than this number of entries in the freelist. +

+ 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. +

+ 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. +

+ 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. +

+ Example: ctdb repack 1000 +

+ By default, this operation is issued from the 00.ctdb event script every 5 minutes. +

vacuum [max_records]

+ Over time CTDB databases will fill up with empty deleted records which will lead to a progressive slow down of CTDB database access. + This command is used to prune all databases and delete all empty records from the cluster. +

+ By default, vacuum will delete all empty records from all databases. + If [max_records] is specified, only databases with that many or more empty records will be pruned. +

+ Vacuum only deletes those records where the local node is the lmaster. + To delete all records from the entire cluster you need to run a vacuum from each node. + + This command is not disruptive. Samba is unaffected and will still be able to read/write records normally while the database is being vacuumed. +

+ Example: ctdb vacuum +

+ By default, this operation is issued from the 00.ctdb event script every 5 minutes. +

Debugging Commands

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

process-exists <pid>

+

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

+

getdbmap

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

Example: ctdb getdbmap @@ -235,21 +269,21 @@ 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>

+

catdb <dbname>

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

getmonmode

+

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>

+

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>

+

attach <dbname>

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

dumpmemory

+

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

+

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. @@ -257,12 +291,12 @@ dbid:0xc0bdde6a name:sessionid.tdb path:/var/ctdb/sessionid.tdb.0 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

Thaw a previously frozen node. -

SEE ALSO

+

SEE ALSO

ctdbd(1), onnode(1) http://ctdb.samba.org/ -

COPYRIGHT/LICENSE


+

COPYRIGHT/LICENSE


Copyright (C) Andrew Tridgell 2007
Copyright (C) Ronnie sahlberg 2007

diff --git a/ctdb/doc/ctdb.1.xml b/ctdb/doc/ctdb.1.xml index 26d9ab9e6e..6fbf830696 100644 --- a/ctdb/doc/ctdb.1.xml +++ b/ctdb/doc/ctdb.1.xml @@ -23,6 +23,7 @@ -n <node> -Y -t <timeout> + -T <timelimit> -? --help --usage -d --debug=<INTEGER> @@ -67,7 +68,17 @@ -t <timeout> - How long should ctdb wait for a command to complete before timing out. Default is 3 seconds. + How long should ctdb wait for the local ctdb daemon to respond to a command before timing out. Default is 3 seconds. + + + + + -T <timelimit> + + + A limit on how long the ctdb command will run for before it will + be aborted. When this timelimit has been exceeded the ctdb command will + terminate. @@ -438,6 +449,64 @@ CTDB version 1 + repack [max_freelist] + + 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. + This command is used to defragment a TDB database and pruning the freelist. + + + + If [max_freelist] is specified, then a database will only be repacked if it has more than this number of entries in the freelist. + + + 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. + + + + 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. + + + + 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. + + + + Example: ctdb repack 1000 + + + + By default, this operation is issued from the 00.ctdb event script every 5 minutes. + + + + + vacuum [max_records] + + Over time CTDB databases will fill up with empty deleted records which will lead to a progressive slow down of CTDB database access. + This command is used to prune all databases and delete all empty records from the cluster. + + + + By default, vacuum will delete all empty records from all databases. + If [max_records] is specified, only databases with that many or more empty records will be pruned. + + + + Vacuum only deletes those records where the local node is the lmaster. + To delete all records from the entire cluster you need to run a vacuum from each node. + + This command is not disruptive. Samba is unaffected and will still be able to read/write records normally while the database is being vacuumed. + + + + Example: ctdb vacuum + + + + By default, this operation is issued from the 00.ctdb event script every 5 minutes. + + + -- cgit