1 <?xml version="1.0" encoding="iso-8859-1"?>
2 <!DOCTYPE refentry PUBLIC "-//Samba-Team//DTD DocBook V4.2-Based Variant V1.0//EN" "http://www.samba.org/samba/DTD/samba-doc">
3 <refentry id="ctdbd.1">
6 <refentrytitle>ctdbd</refentrytitle>
7 <manvolnum>1</manvolnum>
12 <refname>ctdbd</refname>
13 <refpurpose>The CTDB cluster daemon</refpurpose>
18 <command>ctdbd</command>
22 <command>ctdbd</command>
23 <arg choice="opt">-? --help</arg>
24 <arg choice="opt">-d --debug=<INTEGER></arg>
25 <arg choice="req">--dbdir=<directory></arg>
26 <arg choice="req">--dbdir-persistent=<directory></arg>
27 <arg choice="opt">--event-script-dir=<directory></arg>
28 <arg choice="opt">-i --interactive</arg>
29 <arg choice="opt">--listen=<address></arg>
30 <arg choice="opt">--logfile=<filename></arg>
31 <arg choice="req">--nlist=<filename></arg>
32 <arg choice="opt">--nosetsched</arg>
33 <arg choice="opt">--public-addresses=<filename></arg>
34 <arg choice="opt">--public-interface=<interface></arg>
35 <arg choice="req">--reclock=<filename></arg>
36 <arg choice="opt">--single-public-ip=<address></arg>
37 <arg choice="opt">--socket=<filename></arg>
38 <arg choice="opt">--syslog</arg>
39 <arg choice="opt">--torture</arg>
40 <arg choice="opt">--transport=<STRING></arg>
41 <arg choice="opt">--usage</arg>
46 <refsect1><title>DESCRIPTION</title>
48 ctdbd is the main ctdb daemon.
51 ctdbd provides a clustered version of the TDB database with automatic rebuild/recovery of the databases upon nodefailures.
54 Combined with a cluster filesystem ctdbd provides a full HA environment for services such as clustered Samba and NFS as well as other services.
57 ctdbd provides monitoring of all nodes in the cluster and automatically reconfigures the cluster and recovers upon node failures.
60 ctdbd is the main component in clustered Samba that provides a high-awailability load-sharing CIFS server cluster.
66 <title>OPTIONS</title>
69 <varlistentry><term>-? --help</term>
72 Print some help text to the screen.
77 <varlistentry><term>-d --debug=<DEBUGLEVEL></term>
80 This option sets the debuglevel on the ctdbd daemon which controls what will be written to the logfile. The default is 0 which will only log important events and errors. A larger number will provide additional logging.
85 <varlistentry><term>--dbdir=<directory></term>
88 This is the directory on local storage where ctdbd keeps the local
89 copy of the TDB databases. This directory is local for each node and should not be stored on the shared cluster filesystem.
92 This directory would usually be /var/ctdb .
97 <varlistentry><term>--dbdir-persistent=<directory></term>
100 This is the directory on local storage where ctdbd keeps the local
101 copy of the persistent TDB databases. This directory is local for each node and should not be stored on the shared cluster filesystem.
104 This directory would usually be /etc/ctdb/persistent .
109 <varlistentry><term>--event-script-dir=<directory></term>
112 This option is used to specify the directory where the CTDB event
116 This will normally be /etc/ctdb/events.d which is part of the ctdb distribution.
121 <varlistentry><term>-i --interactive</term>
124 By default ctdbd will detach itself from the shell and run in
125 the background as a daemon. This option makes ctdbd to start in interactive mode.
130 <varlistentry><term>--listen=<address></term>
133 This specifies which ip address ctdb will bind to. By default ctdbd will bind to the first address it finds in the /etc/ctdb/nodes file and which is also present on the local system in which case you do not need to provide this option.
136 This option is only required when you want to run multiple ctdbd daemons/nodes on the same physical host in which case there would be multiple entries in /etc/ctdb/nodes what would match a local interface.
141 <varlistentry><term>--logfile=<filename></term>
144 This is the file where ctdbd will write its log. This is usually /var/log/log.ctdb .
149 <varlistentry><term>--nlist=<filename></term>
152 This file contains a list of the private ip addresses of every node in the cluster. There is one line/ip address for each node. This file must be the same for all nodes in the cluster.
155 This file is usually /etc/ctdb/nodes .
160 <varlistentry><term>--nosetsched</term>
163 This is a ctdbd debugging option. this option is only used when
167 Normally ctdb will change its scheduler to run as a real-time
168 process. This is the default mode for a normal ctdbd operation
169 to gurarantee that ctdbd always gets the cpu cycles that it needs.
172 This option is used to tell ctdbd to NOT run as a real-time process
173 and instead run ctdbd as a normal userspace process.
174 This is useful for debugging and when you want to run ctdbd under
175 valgrind or gdb. (You dont want to attach valgrind or gdb to a
181 <varlistentry><term>--public_addresses=<filename></term>
184 When used with IP takeover this specifies a file containing the public ip addresses to use on the cluster. This file contains a list of ip addresses netmasks and interfaces. When ctdb is operational it will distribute these public ip addresses evenly across the available nodes.
187 This is usually the file /etc/ctdb/public_addresses
192 <varlistentry><term>--public-interface=<interface></term>
195 This option tells ctdb which interface to attach public-addresses
196 to and also where to attach the single-public-ip when used.
199 This is only required when using public ip addresses and only when
200 you dont specify the interface explicitely on in /etc/ctdb/public_addresses or when you are using --single-public-ip.
203 If you omit this argument when using public addresses or single public ip, ctdb will not be able to send out Gratious ARPs correctly or be able to kill tcp connections correctly which will lead to application failures.
208 <varlistentry><term>--reclock=<filename></term>
211 This is the name of the lock file stored of the shared cluster filesystem that ctdbd uses to arbitrate which node has the role of recovery-master.
212 This file must be stored on shared storage.
217 <varlistentry><term>--single-public-ip=<address></term>
220 This option is used to activate the "ipmux" or the "lvs"
221 functionality of ctdb where the cluster provides a single
222 public ip address for the entire cluster. When using this option
223 you must also use the --public-interface option.
226 In this mode, all nodes of the cluster will expose a single
227 ip address from all nodes with all incoming traffic to the cluster
228 being passed through the current recmaster. This functionality
229 is similar to using a load-balancing switch.
232 All incoming packets are sent to the recmaster which will multiplex
233 the clients across all available nodes and pass the packets on to
234 a different node in the cluster to manage the connection based
235 on the clients ip address. Outgoing packets however are sent
236 directly from the node that was choosen back to the client.
237 Since all incoming packets are sent through the recmaster this will
238 have a throughput and performance impact when used. This impact
239 in performance primarily affects write-performance while
240 read-performance should be mainly unaffected.
241 Only use this feature if your environment is mostly-read
242 (i.e. most traffic is from the nodes back to the clients) or
243 if it is not important to get maximum write-performance to the
247 This feature is completely controlled from the eventscripts and
248 does not require any CTDBD involvement. However, the CTDBD daemon
249 does need to know that the "single public ip" exists so that the
250 CTDBD daemon will allow clients to set up killtcp to work on this
254 CTDBD only allows clients to use killtcp to kill off (RST) tcp
255 connections to/from an ip address that is either a normal public
256 address or to/from the ip address specified by --single-public-ip.
257 No other tcp connections are allowed to be specified with killtcp.
262 <varlistentry><term>--socket=<filename></term>
265 This specifies the name of the domain socket that ctdbd will create. This socket is used for local clients to attach to and communicate with the ctdbd daemon.
268 The default is /tmp/ctdb.socket . You only need to use this option if you plan to run multiple ctdbd daemons on the same physical host.
273 <varlistentry><term>--syslog</term>
276 Send all log messages to syslog instead of to the ctdb logfile.
281 <varlistentry><term>--torture</term>
284 This option is only used for development and testing of ctdbd. It adds artificial errors and failures to the common codepaths in ctdbd to verify that ctdbd can recover correctly for failures.
287 You do NOT want to use this option unless you are developing and testing new functionality in ctdbd.
292 <varlistentry><term>--transport=<STRING></term>
295 This option specifies which transport to use for ctdbd internode communications. The default is "tcp".
298 Suported transports are "tcp" and "infiniband".
303 <varlistentry><term>--usage</term>
306 Print useage information to the screen.
315 <refsect1><title>Private vs Public addresses</title>
317 When used for ip takeover in a HA environment, each node in a ctdb
318 cluster has multiple ip addresses assigned to it. One private and one or more public.
321 <refsect2><title>Private address</title>
323 This is the physical ip address of the node which is configured in
324 linux and attached to a physical interface. This address uniquely
325 identifies a physical node in the cluster and is the ip addresses
326 that ctdbd will use to communicate with the ctdbd daemons on the
327 other nodes in the cluster.
330 The private addresses are configured in /etc/ctdb/nodes
331 (unless the --nlist option is used) and contain one line for each
332 node in the cluster. Each line contains the private ip address for one
333 node in the cluster. This file must be the same on all nodes in the
337 Since the private addresses are only available to the network when the
338 corresponding node is up and running you should not use these addresses
339 for clients to connect to services provided by the cluster. Instead
340 client applications should only attach to the public addresses since
341 these are guaranteed to always be available.
344 When using ip takeover, it is strongly recommended that the private
345 addresses are configured on a private network physically separated
346 from the rest of the network and that this private network is dedicated
349 Example /etc/ctdb/nodes for a four node cluster:
350 <screen format="linespecific">
357 <refsect2><title>Public address</title>
359 A public address on the other hand is not attached to an interface.
360 This address is managed by ctdbd itself and is attached/detached to
361 a physical node at runtime.
364 The ctdb cluster will assign/reassign these public addresses across the
365 available healthy nodes in the cluster. When one node fails, its public address
366 will be migrated to and taken over by a different node in the cluster
367 to ensure that all public addresses are always available to clients as
368 long as there are still nodes available capable of hosting this address.
371 These addresses are not physically attached to a specific node.
372 The 'ctdb ip' command can be used to view the current assignment of
373 public addresses and which physical node is currently serving it.
376 On each node this file contains a list of the public addresses that
377 this node is capable of hosting.
378 The list also contain the netmask and the
379 interface where this address should be attached for the case where you
380 may want to serve data out through multiple different interfaces.
382 Example /etc/ctdb/public_addresses for a node that can host 4 public addresses:
383 <screen format="linespecific">
391 In most cases this file would be the same on all nodes in a cluster but
392 there are exceptions when one may want to use different files
395 Example: 4 nodes partitioned into two subgroups :
396 <screen format="linespecific">
397 Node 0:/etc/ctdb/public_addresses
401 Node 1:/etc/ctdb/public_addresses
405 Node 2:/etc/ctdb/public_addresses
409 Node 3:/etc/ctdb/public_addresses
414 In this example nodes 0 and 1 host two public addresses on the
415 10.1.1.x network while nodes 2 and 3 host two public addresses for the
419 Ip address 10.1.1.1 can be hosted by either of nodes 0 or 1 and will be
420 available to clients as long as at least one of these two nodes are
422 If both nodes 0 and node 1 become unavailable 10.1.1.1 also becomes
423 unavailable. 10.1.1.1 can not be failed over to node 2 or node 3 since
424 these nodes do not have this ip address listed in their public
431 <refsect1><title>Node status</title>
433 The current status of each node in the cluster can be viewed by the
434 'ctdb status' command.
437 There are five possible for a node.
441 OK - This node is fully functional.
445 DISCONNECTED - This node could not be connected through the network
446 and is currently not particpating in the cluster. If there is a
447 public IP address associated with this node it should have been taken
448 over by a different node. No services are running on this node.
452 DISABLED - This node has been administratively disabled. This node is
453 still functional and participates in the CTDB cluster but its IP
454 addresses have been taken over by a different node and no services are
455 currently being hosted.
459 UNHEALTHY - A service provided by this node is malfunctioning and should
460 be investigated. The CTDB daemon itself is operational and participates
461 in the cluster. Its public IP address has been taken over by a different
462 node and no services are currently being hosted. All unhealthy nodes
463 should be investigated and require an administrative action to rectify.
467 BANNED - This node failed too many recovery attempts and has been banned
468 from participating in the cluster for a period of RecoveryBanPeriod
469 seconds. Any public IP address has been taken over by other nodes. This
470 node does not provide any services. All banned nodes should be
471 investigated and require an administrative action to rectify. This node
472 does not perticipate in the CTDB cluster but can still be communicated
473 with. I.e. ctdb commands can be sent to it.
478 <refsect1><title>SEE ALSO</title>
481 <ulink url="http://ctdb.samba.org/"/>
484 <refsect1><title>COPYRIGHT/LICENSE</title>
486 Copyright (C) Andrew Tridgell 2007
487 Copyright (C) Ronnie sahlberg 2007
489 This program is free software; you can redistribute it and/or modify
490 it under the terms of the GNU General Public License as published by
491 the Free Software Foundation; either version 3 of the License, or (at
492 your option) any later version.
494 This program is distributed in the hope that it will be useful, but
495 WITHOUT ANY WARRANTY; without even the implied warranty of
496 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
497 General Public License for more details.
499 You should have received a copy of the GNU General Public License
500 along with this program; if not, see http://www.gnu.org/licenses/.