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.
201 <varlistentry><term>--reclock=<filename></term>
204 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.
205 This file must be stored on shared storage.
210 <varlistentry><term>--single-public-ip=<address></term>
213 This option is used to activate the "ipmux" functionality of ctdb.
214 In this mode, all nodes of the cluster will expose a single
215 ip address from all nodes with all incoming traffic to the cluster
216 being passed through the current recmaster. This functionality
217 is similar to using a load-balancing switch.
220 All incoming packets are sent to the recmaster which will multiplex
221 the clients across all available nodes and pass the packets on to
222 a different node in the cluster to manage the connection based
223 on the clients ip address. Outgoing packets however are sent
224 directly from the node that was choosen back to the client.
225 Since all incoming packets are sent through the recmaster this will
226 have a throughput and performance impact when used. This impact
227 in performance primarily affects write-performance while
228 read-performance should be mainly unaffected.
229 Only use this feature if your environment is mostly-read
230 (i.e. most traffic is from the nodes back to the clients) or
231 if it is not important to get maximum write-performance to the
235 When using a single public ip, you must also specify the
236 public-interface so that ctdb knows which interface to attach the
242 <varlistentry><term>--socket=<filename></term>
245 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.
248 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.
253 <varlistentry><term>--syslog</term>
256 Send all log messages to syslog instead of to the ctdb logfile.
261 <varlistentry><term>--torture</term>
264 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.
267 You do NOT want to use this option unless you are developing and testing new functionality in ctdbd.
272 <varlistentry><term>--transport=<STRING></term>
275 This option specifies which transport to use for ctdbd internode communications. The default is "tcp".
278 Suported transports are "tcp" and "infiniband".
283 <varlistentry><term>--usage</term>
286 Print useage information to the screen.
295 <refsect1><title>Private vs Public addresses</title>
297 When used for ip takeover in a HA environment, each node in a ctdb
298 cluster has multiple ip addresses assigned to it. One private and one or more public.
301 <refsect2><title>Private address</title>
303 This is the physical ip address of the node which is configured in
304 linux and attached to a physical interface. This address uniquely
305 identifies a physical node in the cluster and is the ip addresses
306 that ctdbd will use to communicate with the ctdbd daemons on the
307 other nodes in the cluster.
310 The private addresses are configured in /etc/ctdb/nodes
311 (unless the --nlist option is used) and contain one line for each
312 node in the cluster. Each line contains the private ip address for one
313 node in the cluster. This file must be the same on all nodes in the
317 Since the private addresses are only available to the network when the
318 corresponding node is up and running you should not use these addresses
319 for clients to connect to services provided by the cluster. Instead
320 client applications should only attach to the public addresses since
321 these are guaranteed to always be available.
324 When using ip takeover, it is strongly recommended that the private
325 addresses are configured on a private network physically separated
326 from the rest of the network and that this private network is dedicated
329 Example /etc/ctdb/nodes for a four node cluster:
330 <screen format="linespecific">
337 <refsect2><title>Public address</title>
339 A public address on the other hand is not attached to an interface.
340 This address is managed by ctdbd itself and is attached/detached to
341 a physical node at runtime.
344 The ctdb cluster will assign/reassign these public addresses across the
345 available healthy nodes in the cluster. When one node fails, its public address
346 will be migrated to and taken over by a different node in the cluster
347 to ensure that all public addresses are always available to clients as
348 long as there are still nodes available capable of hosting this address.
351 These addresses are not physically attached to a specific node.
352 The 'ctdb ip' command can be used to view the current assignment of
353 public addresses and which physical node is currently serving it.
356 On each node this file contains a list of the public addresses that
357 this node is capable of hosting.
358 The list also contain the netmask and the
359 interface where this address should be attached for the case where you
360 may want to serve data out through multiple different interfaces.
362 Example /etc/ctdb/public_addresses for a node that can host 4 public addresses:
363 <screen format="linespecific">
371 In most cases this file would be the same on all nodes in a cluster but
372 there are exceptions when one may want to use different files
375 Example: 4 nodes partitioned into two subgroups :
376 <screen format="linespecific">
377 Node 0:/etc/ctdb/public_addresses
381 Node 1:/etc/ctdb/public_addresses
385 Node 2:/etc/ctdb/public_addresses
389 Node 3:/etc/ctdb/public_addresses
394 In this example nodes 0 and 1 host two public addresses on the
395 10.1.1.x network while nodes 2 and 3 host two public addresses for the
399 Ip address 10.1.1.1 can be hosted by either of nodes 0 or 1 and will be
400 available to clients as long as at least one of these two nodes are
402 If both nodes 0 and node 1 become unavailable 10.1.1.1 also becomes
403 unavailable. 10.1.1.1 can not be failed over to node 2 or node 3 since
404 these nodes do not have this ip address listed in their public
411 <refsect1><title>Node status</title>
413 The current status of each node in the cluster can be viewed by the
414 'ctdb status' command.
417 There are five possible for a node.
421 OK - This node is fully functional.
425 DISCONNECTED - This node could not be connected through the network
426 and is currently not particpating in the cluster. If there is a
427 public IP address associated with this node it should have been taken
428 over by a different node. No services are running on this node.
432 DISABLED - This node has been administratively disabled. This node is
433 still functional and participates in the CTDB cluster but its IP
434 addresses have been taken over by a different node and no services are
435 currently being hosted.
439 UNHEALTHY - A service provided by this node is malfunctioning and should
440 be investigated. The CTDB daemon itself is operational and participates
441 in the cluster. Its public IP address has been taken over by a different
442 node and no services are currently being hosted. All unhealthy nodes
443 should be investigated and require an administrative action to rectify.
447 BANNED - This node failed too many recovery attempts and has been banned
448 from participating in the cluster for a period of RecoveryBanPeriod
449 seconds. Any public IP address has been taken over by other nodes. This
450 node does not provide any services. All banned nodes should be
451 investigated and require an administrative action to rectify. This node
452 does not perticipate in the CTDB cluster but can still be communicated
453 with. I.e. ctdb commands can be sent to it.
458 <refsect1><title>SEE ALSO</title>
461 <ulink url="http://ctdb.samba.org/"/>
464 <refsect1><title>COPYRIGHT/LICENSE</title>
466 Copyright (C) Andrew Tridgell 2007
467 Copyright (C) Ronnie sahlberg 2007
469 This program is free software; you can redistribute it and/or modify
470 it under the terms of the GNU General Public License as published by
471 the Free Software Foundation; either version 3 of the License, or (at
472 your option) any later version.
474 This program is distributed in the hope that it will be useful, but
475 WITHOUT ANY WARRANTY; without even the implied warranty of
476 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
477 General Public License for more details.
479 You should have received a copy of the GNU General Public License
480 along with this program; if not, see http://www.gnu.org/licenses/.