1 <html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>ctdbd</title><meta name="generator" content="DocBook XSL Stylesheets V1.71.0"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="refentry" lang="en"><a name="ctdbd.1"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>ctdbd — The CTDB cluster daemon</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="cmdsynopsis"><p><code class="command">ctdbd</code> </p></div><div class="cmdsynopsis"><p><code class="command">ctdbd</code> [-? --help] [-d --debug=<INTEGER>] {--dbdir=<directory>} {--dbdir-persistent=<directory>} [--event-script-dir=<directory>] [-i --interactive] [--listen=<address>] [--logfile=<filename>] {--nlist=<filename>} [--nosetsched] [--public-addresses=<filename>] [--public-interface=<interface>] {--reclock=<filename>} [--single-public-ip=<address>] [--socket=<filename>] [--syslog] [--torture] [--transport=<STRING>] [--usage]</p></div></div><div class="refsect1" lang="en"><a name="id2481142"></a><h2>DESCRIPTION</h2><p>
2 ctdbd is the main ctdb daemon.
4 ctdbd provides a clustered version of the TDB database with automatic rebuild/recovery of the databases upon nodefailures.
6 Combined with a cluster filesystem ctdbd provides a full HA environment for services such as clustered Samba and NFS as well as other services.
8 ctdbd provides monitoring of all nodes in the cluster and automatically reconfigures the cluster and recovers upon node failures.
10 ctdbd is the main component in clustered Samba that provides a high-awailability load-sharing CIFS server cluster.
11 </p></div><div class="refsect1" lang="en"><a name="id2481175"></a><h2>OPTIONS</h2><div class="variablelist"><dl><dt><span class="term">-? --help</span></dt><dd><p>
12 Print some help text to the screen.
13 </p></dd><dt><span class="term">-d --debug=<DEBUGLEVEL></span></dt><dd><p>
14 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.
15 </p></dd><dt><span class="term">--dbdir=<directory></span></dt><dd><p>
16 This is the directory on local storage where ctdbd keeps the local
17 copy of the TDB databases. This directory is local for each node and should not be stored on the shared cluster filesystem.
19 This directory would usually be /var/ctdb .
20 </p></dd><dt><span class="term">--dbdir-persistent=<directory></span></dt><dd><p>
21 This is the directory on local storage where ctdbd keeps the local
22 copy of the persistent TDB databases. This directory is local for each node and should not be stored on the shared cluster filesystem.
24 This directory would usually be /etc/ctdb/persistent .
25 </p></dd><dt><span class="term">--event-script-dir=<directory></span></dt><dd><p>
26 This option is used to specify the directory where the CTDB event
29 This will normally be /etc/ctdb/events.d which is part of the ctdb distribution.
30 </p></dd><dt><span class="term">-i --interactive</span></dt><dd><p>
31 By default ctdbd will detach itself from the shell and run in
32 the background as a daemon. This option makes ctdbd to start in interactive mode.
33 </p></dd><dt><span class="term">--listen=<address></span></dt><dd><p>
34 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.
36 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.
37 </p></dd><dt><span class="term">--logfile=<filename></span></dt><dd><p>
38 This is the file where ctdbd will write its log. This is usually /var/log/log.ctdb .
39 </p></dd><dt><span class="term">--nlist=<filename></span></dt><dd><p>
40 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.
42 This file is usually /etc/ctdb/nodes .
43 </p></dd><dt><span class="term">--nosetsched</span></dt><dd><p>
44 This is a ctdbd debugging option. this option is only used when
47 Normally ctdb will change its scheduler to run as a real-time
48 process. This is the default mode for a normal ctdbd operation
49 to gurarantee that ctdbd always gets the cpu cycles that it needs.
51 This option is used to tell ctdbd to NOT run as a real-time process
52 and instead run ctdbd as a normal userspace process.
53 This is useful for debugging and when you want to run ctdbd under
54 valgrind or gdb. (You dont want to attach valgrind or gdb to a
56 </p></dd><dt><span class="term">--public_addresses=<filename></span></dt><dd><p>
57 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.
59 This is usually the file /etc/ctdb/public_addresses
60 </p></dd><dt><span class="term">--public-interface=<interface></span></dt><dd><p>
61 This option tells ctdb which interface to attach public-addresses
62 to and also where to attach the single-public-ip when used.
64 This is only required when using public ip addresses and only when
65 you dont specify the interface explicitely on in /etc/ctdb/public_addresses or when you are using --single-public-ip.
67 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.
68 </p></dd><dt><span class="term">--reclock=<filename></span></dt><dd><p>
69 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.
70 This file must be stored on shared storage.
71 </p></dd><dt><span class="term">--single-public-ip=<address></span></dt><dd><p>
72 This option is used to activate the "ipmux" or the "lvs"
73 functionality of ctdb where the cluster provides a single
74 public ip address for the entire cluster. When using this option
75 you must also use the --public-interface option.
77 In this mode, all nodes of the cluster will expose a single
78 ip address from all nodes with all incoming traffic to the cluster
79 being passed through the current recmaster. This functionality
80 is similar to using a load-balancing switch.
82 All incoming packets are sent to the recmaster which will multiplex
83 the clients across all available nodes and pass the packets on to
84 a different node in the cluster to manage the connection based
85 on the clients ip address. Outgoing packets however are sent
86 directly from the node that was choosen back to the client.
87 Since all incoming packets are sent through the recmaster this will
88 have a throughput and performance impact when used. This impact
89 in performance primarily affects write-performance while
90 read-performance should be mainly unaffected.
91 Only use this feature if your environment is mostly-read
92 (i.e. most traffic is from the nodes back to the clients) or
93 if it is not important to get maximum write-performance to the
96 This feature is completely controlled from the eventscripts and
97 does not require any CTDBD involvement. However, the CTDBD daemon
98 does need to know that the "single public ip" exists so that the
99 CTDBD daemon will allow clients to set up killtcp to work on this
102 CTDBD only allows clients to use killtcp to kill off (RST) tcp
103 connections to/from an ip address that is either a normal public
104 address or to/from the ip address specified by --single-public-ip.
105 No other tcp connections are allowed to be specified with killtcp.
106 </p></dd><dt><span class="term">--socket=<filename></span></dt><dd><p>
107 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.
109 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.
110 </p></dd><dt><span class="term">--syslog</span></dt><dd><p>
111 Send all log messages to syslog instead of to the ctdb logfile.
112 </p></dd><dt><span class="term">--torture</span></dt><dd><p>
113 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.
115 You do NOT want to use this option unless you are developing and testing new functionality in ctdbd.
116 </p></dd><dt><span class="term">--transport=<STRING></span></dt><dd><p>
117 This option specifies which transport to use for ctdbd internode communications. The default is "tcp".
119 Currently only "tcp" is supported but "infiniband" might be
120 implemented in the future.
121 </p></dd><dt><span class="term">--usage</span></dt><dd><p>
122 Print useage information to the screen.
123 </p></dd></dl></div></div><div class="refsect1" lang="en"><a name="id2528652"></a><h2>Private vs Public addresses</h2><p>
124 When used for ip takeover in a HA environment, each node in a ctdb
125 cluster has multiple ip addresses assigned to it. One private and one or more public.
126 </p><div class="refsect2" lang="en"><a name="id2528663"></a><h3>Private address</h3><p>
127 This is the physical ip address of the node which is configured in
128 linux and attached to a physical interface. This address uniquely
129 identifies a physical node in the cluster and is the ip addresses
130 that ctdbd will use to communicate with the ctdbd daemons on the
131 other nodes in the cluster.
133 The private addresses are configured in /etc/ctdb/nodes
134 (unless the --nlist option is used) and contain one line for each
135 node in the cluster. Each line contains the private ip address for one
136 node in the cluster. This file must be the same on all nodes in the
139 Since the private addresses are only available to the network when the
140 corresponding node is up and running you should not use these addresses
141 for clients to connect to services provided by the cluster. Instead
142 client applications should only attach to the public addresses since
143 these are guaranteed to always be available.
145 When using ip takeover, it is strongly recommended that the private
146 addresses are configured on a private network physically separated
147 from the rest of the network and that this private network is dedicated
150 Example /etc/ctdb/nodes for a four node cluster:
156 </pre></div><div class="refsect2" lang="en"><a name="id2528711"></a><h3>Public address</h3><p>
157 A public address on the other hand is not attached to an interface.
158 This address is managed by ctdbd itself and is attached/detached to
159 a physical node at runtime.
161 The ctdb cluster will assign/reassign these public addresses across the
162 available healthy nodes in the cluster. When one node fails, its public address
163 will be migrated to and taken over by a different node in the cluster
164 to ensure that all public addresses are always available to clients as
165 long as there are still nodes available capable of hosting this address.
167 These addresses are not physically attached to a specific node.
168 The 'ctdb ip' command can be used to view the current assignment of
169 public addresses and which physical node is currently serving it.
171 On each node this file contains a list of the public addresses that
172 this node is capable of hosting.
173 The list also contain the netmask and the
174 interface where this address should be attached for the case where you
175 may want to serve data out through multiple different interfaces.
177 Example /etc/ctdb/public_addresses for a node that can host 4 public addresses:
184 In most cases this file would be the same on all nodes in a cluster but
185 there are exceptions when one may want to use different files
188 Example: 4 nodes partitioned into two subgroups :
190 Node 0:/etc/ctdb/public_addresses
194 Node 1:/etc/ctdb/public_addresses
198 Node 2:/etc/ctdb/public_addresses
202 Node 3:/etc/ctdb/public_addresses
206 In this example nodes 0 and 1 host two public addresses on the
207 10.1.1.x network while nodes 2 and 3 host two public addresses for the
210 Ip address 10.1.1.1 can be hosted by either of nodes 0 or 1 and will be
211 available to clients as long as at least one of these two nodes are
213 If both nodes 0 and node 1 become unavailable 10.1.1.1 also becomes
214 unavailable. 10.1.1.1 can not be failed over to node 2 or node 3 since
215 these nodes do not have this ip address listed in their public
217 </p></div></div><div class="refsect1" lang="en"><a name="id2528793"></a><h2>Node status</h2><p>
218 The current status of each node in the cluster can be viewed by the
219 'ctdb status' command.
221 There are five possible for a node.
223 OK - This node is fully functional.
225 DISCONNECTED - This node could not be connected through the network
226 and is currently not particpating in the cluster. If there is a
227 public IP address associated with this node it should have been taken
228 over by a different node. No services are running on this node.
230 DISABLED - This node has been administratively disabled. This node is
231 still functional and participates in the CTDB cluster but its IP
232 addresses have been taken over by a different node and no services are
233 currently being hosted.
235 UNHEALTHY - A service provided by this node is malfunctioning and should
236 be investigated. The CTDB daemon itself is operational and participates
237 in the cluster. Its public IP address has been taken over by a different
238 node and no services are currently being hosted. All unhealthy nodes
239 should be investigated and require an administrative action to rectify.
241 BANNED - This node failed too many recovery attempts and has been banned
242 from participating in the cluster for a period of RecoveryBanPeriod
243 seconds. Any public IP address has been taken over by other nodes. This
244 node does not provide any services. All banned nodes should be
245 investigated and require an administrative action to rectify. This node
246 does not perticipate in the CTDB cluster but can still be communicated
247 with. I.e. ctdb commands can be sent to it.
248 </p></div><div class="refsect1" lang="en"><a name="id2528850"></a><h2>SEE ALSO</h2><p>
250 <a href="http://ctdb.samba.org/" target="_top">http://ctdb.samba.org/</a>
251 </p></div><div class="refsect1" lang="en"><a name="id2528863"></a><h2>COPYRIGHT/LICENSE</h2><div class="literallayout"><p><br>
252 Copyright (C) Andrew Tridgell 2007<br>
253 Copyright (C) Ronnie sahlberg 2007<br>
255 This program is free software; you can redistribute it and/or modify<br>
256 it under the terms of the GNU General Public License as published by<br>
257 the Free Software Foundation; either version 3 of the License, or (at<br>
258 your option) any later version.<br>
260 This program is distributed in the hope that it will be useful, but<br>
261 WITHOUT ANY WARRANTY; without even the implied warranty of<br>
262 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU<br>
263 General Public License for more details.<br>
265 You should have received a copy of the GNU General Public License<br>
266 along with this program; if not, see http://www.gnu.org/licenses/.<br>
267 </p></div></div></div></body></html>