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="opt">--lvs</arg>
32 <arg choice="req">--nlist=<filename></arg>
33 <arg choice="opt">--no-lmaster</arg>
34 <arg choice="opt">--no-recmaster</arg>
35 <arg choice="opt">--nosetsched</arg>
36 <arg choice="req">--notification-script=<filename></arg>
37 <arg choice="opt">--public-addresses=<filename></arg>
38 <arg choice="opt">--public-interface=<interface></arg>
39 <arg choice="req">--reclock=<filename></arg>
40 <arg choice="opt">--single-public-ip=<address></arg>
41 <arg choice="opt">--socket=<filename></arg>
42 <arg choice="opt">--start-as-disabled</arg>
43 <arg choice="opt">--start-as-stopped</arg>
44 <arg choice="opt">--syslog</arg>
45 <arg choice="opt">--torture</arg>
46 <arg choice="opt">--transport=<STRING></arg>
47 <arg choice="opt">--usage</arg>
52 <refsect1><title>DESCRIPTION</title>
54 ctdbd is the main ctdb daemon.
57 ctdbd provides a clustered version of the TDB database with automatic rebuild/recovery of the databases upon nodefailures.
60 Combined with a cluster filesystem ctdbd provides a full HA environment for services such as clustered Samba and NFS as well as other services.
63 ctdbd provides monitoring of all nodes in the cluster and automatically reconfigures the cluster and recovers upon node failures.
66 ctdbd is the main component in clustered Samba that provides a high-availability load-sharing CIFS server cluster.
72 <title>OPTIONS</title>
75 <varlistentry><term>-? --help</term>
78 Print some help text to the screen.
83 <varlistentry><term>-d --debug=<DEBUGLEVEL></term>
86 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.
91 <varlistentry><term>--dbdir=<directory></term>
94 This is the directory on local storage where ctdbd keeps the local
95 copy of the TDB databases. This directory is local for each node and should not be stored on the shared cluster filesystem.
98 This directory would usually be /var/ctdb .
103 <varlistentry><term>--dbdir-persistent=<directory></term>
106 This is the directory on local storage where ctdbd keeps the local
107 copy of the persistent TDB databases. This directory is local for each node and should not be stored on the shared cluster filesystem.
110 This directory would usually be /etc/ctdb/persistent .
115 <varlistentry><term>--event-script-dir=<directory></term>
118 This option is used to specify the directory where the CTDB event
122 This will normally be /etc/ctdb/events.d which is part of the ctdb distribution.
127 <varlistentry><term>-i --interactive</term>
130 By default ctdbd will detach itself from the shell and run in
131 the background as a daemon. This option makes ctdbd to start in interactive mode.
136 <varlistentry><term>--listen=<address></term>
139 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.
142 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.
147 <varlistentry><term>--logfile=<filename></term>
150 This is the file where ctdbd will write its log. This is usually /var/log/log.ctdb .
155 <varlistentry><term>--lvs</term>
158 This option is used to activate the LVS capability on a CTDB node.
159 Please see the LVS section.
164 <varlistentry><term>--nlist=<filename></term>
167 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.
170 This file is usually /etc/ctdb/nodes .
175 <varlistentry><term>--no-lmaster</term>
178 This argument specifies that this node can NOT become an lmaster
179 for records in the database. This means that it will never show up
180 in the vnnmap. This feature is primarily used for making a cluster
181 span across a WAN link and use CTDB as a WAN-accelerator.
184 Please see the "remote cluster nodes" section for more information.
189 <varlistentry><term>--no-recmaster</term>
192 This argument specifies that this node can NOT become a recmaster
193 for the database. This feature is primarily used for making a cluster
194 span across a WAN link and use CTDB as a WAN-accelerator.
197 Please see the "remote cluster nodes" section for more information.
202 <varlistentry><term>--nosetsched</term>
205 This is a ctdbd debugging option. this option is only used when
209 Normally ctdb will change its scheduler to run as a real-time
210 process. This is the default mode for a normal ctdbd operation
211 to gurarantee that ctdbd always gets the cpu cycles that it needs.
214 This option is used to tell ctdbd to NOT run as a real-time process
215 and instead run ctdbd as a normal userspace process.
216 This is useful for debugging and when you want to run ctdbd under
217 valgrind or gdb. (You dont want to attach valgrind or gdb to a
223 <varlistentry><term>--notification-script=<filename></term>
226 This specifies a script which will be invoked by ctdb when certain
227 state changes occur in ctdbd and when you may want to trigger this
228 to run certain scripts.
231 This file is usually /etc/ctdb/notify.sh .
234 See the NOTIFICATION SCRIPT section below for more information.
239 <varlistentry><term>--public_addresses=<filename></term>
242 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.
245 This is usually the file /etc/ctdb/public_addresses
250 <varlistentry><term>--public-interface=<interface></term>
253 This option tells ctdb which interface to attach public-addresses
254 to and also where to attach the single-public-ip when used.
257 This is only required when using public ip addresses and only when
258 you dont specify the interface explicitly in /etc/ctdb/public_addresses or when you are using --single-public-ip.
261 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.
266 <varlistentry><term>--reclock=<filename></term>
269 This is the name of the lock file stored of the shared cluster filesystem that ctdbd uses to prevent split brains from occuring.
270 This file must be stored on shared storage.
273 It is possible to run CTDB without a reclock file, but then there
274 will be no protection against split brain if the network becomes
275 partitioned. Using CTDB without a reclock file is strongly
281 <varlistentry><term>--socket=<filename></term>
284 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.
287 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.
292 <varlistentry><term>--start-as-disabled</term>
295 This makes the ctdb daemon to be DISABLED when it starts up.
298 As it is DISABLED it will not get any of the public ip addresses
299 allocated to it, and thus this allow you to start ctdb on a node
300 without causing any ip address to failover from other nodes onto
304 When used, the administrator must keep track of when nodes start and
305 manually enable them again using the "ctdb enable" command, or else
306 the node will not host any services.
309 A node that is DISABLED will not host any services and will not be
310 reachable/used by any clients.
315 <varlistentry><term>--start-as-stopped</term>
318 This makes the ctdb daemon to be STOPPED when it starts up.
321 A node that is STOPPED does not host any public addresses. It is not part of the VNNMAP so it does act as an LMASTER. It also has all databases locked in recovery mode until restarted.
324 To restart and activate a STOPPED node, the command "ctdb continue" is used.
327 A node that is STOPPED will not host any services and will not be
328 reachable/used by any clients.
333 <varlistentry><term>--syslog</term>
336 Send all log messages to syslog instead of to the ctdb logfile.
341 <varlistentry><term>--torture</term>
344 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.
347 You do NOT want to use this option unless you are developing and testing new functionality in ctdbd.
352 <varlistentry><term>--transport=<STRING></term>
355 This option specifies which transport to use for ctdbd internode communications. The default is "tcp".
358 Currently only "tcp" is supported but "infiniband" might be
359 implemented in the future.
364 <varlistentry><term>--usage</term>
367 Print useage information to the screen.
376 <refsect1><title>Private vs Public addresses</title>
378 When used for ip takeover in a HA environment, each node in a ctdb
379 cluster has multiple ip addresses assigned to it. One private and one or more public.
382 <refsect2><title>Private address</title>
384 This is the physical ip address of the node which is configured in
385 linux and attached to a physical interface. This address uniquely
386 identifies a physical node in the cluster and is the ip addresses
387 that ctdbd will use to communicate with the ctdbd daemons on the
388 other nodes in the cluster.
391 The private addresses are configured in /etc/ctdb/nodes
392 (unless the --nlist option is used) and contain one line for each
393 node in the cluster. Each line contains the private ip address for one
394 node in the cluster. This file must be the same on all nodes in the
398 Since the private addresses are only available to the network when the
399 corresponding node is up and running you should not use these addresses
400 for clients to connect to services provided by the cluster. Instead
401 client applications should only attach to the public addresses since
402 these are guaranteed to always be available.
405 When using ip takeover, it is strongly recommended that the private
406 addresses are configured on a private network physically separated
407 from the rest of the network and that this private network is dedicated
410 Example /etc/ctdb/nodes for a four node cluster:
411 <screen format="linespecific">
418 <refsect2><title>Public address</title>
420 A public address on the other hand is not attached to an interface.
421 This address is managed by ctdbd itself and is attached/detached to
422 a physical node at runtime.
425 The ctdb cluster will assign/reassign these public addresses across the
426 available healthy nodes in the cluster. When one node fails, its public address
427 will be migrated to and taken over by a different node in the cluster
428 to ensure that all public addresses are always available to clients as
429 long as there are still nodes available capable of hosting this address.
432 These addresses are not physically attached to a specific node.
433 The 'ctdb ip' command can be used to view the current assignment of
434 public addresses and which physical node is currently serving it.
437 On each node this file contains a list of the public addresses that
438 this node is capable of hosting.
439 The list also contain the netmask and the
440 interface where this address should be attached for the case where you
441 may want to serve data out through multiple different interfaces.
443 Example /etc/ctdb/public_addresses for a node that can host 4 public addresses:
444 <screen format="linespecific">
452 In most cases this file would be the same on all nodes in a cluster but
453 there are exceptions when one may want to use different files
456 Example: 4 nodes partitioned into two subgroups :
457 <screen format="linespecific">
458 Node 0:/etc/ctdb/public_addresses
462 Node 1:/etc/ctdb/public_addresses
466 Node 2:/etc/ctdb/public_addresses
470 Node 3:/etc/ctdb/public_addresses
475 In this example nodes 0 and 1 host two public addresses on the
476 10.1.1.x network while nodes 2 and 3 host two public addresses for the
480 Ip address 10.1.1.1 can be hosted by either of nodes 0 or 1 and will be
481 available to clients as long as at least one of these two nodes are
483 If both nodes 0 and node 1 become unavailable 10.1.1.1 also becomes
484 unavailable. 10.1.1.1 can not be failed over to node 2 or node 3 since
485 these nodes do not have this ip address listed in their public
492 <refsect1><title>Node status</title>
494 The current status of each node in the cluster can be viewed by the
495 'ctdb status' command.
498 There are five possible states for a node.
502 OK - This node is fully functional.
506 DISCONNECTED - This node could not be connected through the network
507 and is currently not particpating in the cluster. If there is a
508 public IP address associated with this node it should have been taken
509 over by a different node. No services are running on this node.
513 DISABLED - This node has been administratively disabled. This node is
514 still functional and participates in the CTDB cluster but its IP
515 addresses have been taken over by a different node and no services are
516 currently being hosted.
520 UNHEALTHY - A service provided by this node is malfunctioning and should
521 be investigated. The CTDB daemon itself is operational and participates
522 in the cluster. Its public IP address has been taken over by a different
523 node and no services are currently being hosted. All unhealthy nodes
524 should be investigated and require an administrative action to rectify.
528 BANNED - This node failed too many recovery attempts and has been banned
529 from participating in the cluster for a period of RecoveryBanPeriod
530 seconds. Any public IP address has been taken over by other nodes. This
531 node does not provide any services. All banned nodes should be
532 investigated and require an administrative action to rectify. This node
533 does not perticipate in the CTDB cluster but can still be communicated
534 with. I.e. ctdb commands can be sent to it.
538 STOPPED - A node that is stopped does not host any public ip addresses,
539 nor is it part of the VNNMAP. A stopped node can not become LVSMASTER,
541 This node does not perticipate in the CTDB cluster but can still be
542 communicated with. I.e. ctdb commands can be sent to it.
547 <title>PUBLIC TUNABLES</title>
549 These are the public tuneables that can be used to control how ctdb behaves.
552 <refsect2><title>KeepaliveInterval</title>
553 <para>Default: 1</para>
555 How often should the nodes send keepalives to eachother.
558 <refsect2><title>KeepaliveLimit</title>
559 <para>Default: 5</para>
561 After how many keepalive intervals without any traffic should a node
562 wait until marking the peer as DISCONNECTED.
565 <refsect2><title>MonitorInterval</title>
566 <para>Default: 15</para>
568 How often should ctdb run the event scripts to check for a nodes health.
571 <refsect2><title>TickleUpdateInterval</title>
572 <para>Default: 20</para>
574 How often will ctdb record and store the "tickle" information used to
575 kickstart stalled tcp connections after a recovery.
578 <refsect2><title>EventScriptTimeout</title>
579 <para>Default: 20</para>
581 How long should ctdb let an event script run before aborting it and
582 marking the node unhealthy.
585 <refsect2><title>RecoveryBanPeriod</title>
586 <para>Default: 300</para>
588 If a node becomes banned causing repetitive recovery failures. The node will
589 eventually become banned from the cluster.
590 This controls how long the culprit node will be banned from the cluster
591 before it is allowed to try to join the cluster again.
592 Dont set to small. A node gets banned for a reason and it is usually due
593 to real problems with the node.
596 <refsect2><title>DatabaseHashSize</title>
597 <para>Default: 100000</para>
599 Size of the hash chains for the local store of the tdbs that ctdb manages.
602 <refsect2><title>RerecoveryTimeout</title>
603 <para>Default: 10</para>
605 Once a recovery has completed, no additional recoveries are permitted until this timeout has expired.
608 <refsect2><title>EnableBans</title>
609 <para>Default: 1</para>
611 When set to 0, this disables BANNING completely in the cluster and thus nodes can not get banned, even it they break. Dont set to 0.
614 <refsect2><title>DeterministicIPs</title>
615 <para>Default: 1</para>
617 When enabled, this tunable makes ctdb try to keep public IP addresses locked to specific nodes as far as possible. This makes it easier for debugging since you can know that as long as all nodes are healthy public IP X will always be hosted by node Y.
620 The cost of using deterministic IP address assignment is that it disables part of the logic where ctdb tries to reduce the number of public IP assignment changes in the cluster. This tunable may increase the number of IP failover/failbacks that are performed on the cluster by a small margin.
623 <refsect2><title>DisableWhenUnhealthy</title>
624 <para>Default: 0</para>
626 When set, As soon as a node becomes unhealthy, that node will also automatically become permanently DISABLED. Once a node is DISABLED, the only way to make it participate in the cluster again and host services is by manually enabling the node again using 'ctdb enable'.
629 This disables parts of the resilience and robustness of the cluster and should ONLY be used when the system administrator is actively monitoring the cluster, so that nodes can be enabled again.
632 <refsect2><title>NoIPFailback</title>
633 <para>Default: 0</para>
635 When set to 1, ctdb will not perform failback of IP addresses when a node becomes healthy. Ctdb WILL perform failover of public IP addresses when a node becomes UNHEALTHY, but when the node becomes HEALTHY again, ctdb will not fail the addresses back.
638 Use with caution! Normally when a node becomes available to the cluster
639 ctdb will try to reassign public IP addresses onto the new node as a way to distribute the workload evenly across the clusternode. Ctdb tries to make sure that all running nodes have approximately the same number of public addresses it hosts.
642 When you enable this tunable, CTDB will no longer attempt to rebalance the cluster by failing IP addresses back to the new nodes. An unbalanced cluster will therefore remain unbalanced until there is manual intervention from the administrator. When this parameter is set, you can manually fail public IP addresses over to the new node(s) using the 'ctdb moveip' command.
647 <refsect1><title>LVS</title>
649 LVS is a mode where CTDB presents one single IP address for the entire
650 cluster. This is an alternative to using public IP addresses and round-robin
651 DNS to loadbalance clients across the cluster.
655 This is similar to using a layer-4 loadbalancing switch but with some restrictions.
659 In this mode the cluster select a set of nodes in the cluster and loadbalance
660 all client access to the LVS address across this set of nodes. This set of nodes are all LVS capable nodes that are HEALTHY, or if no HEALTHY nodes exists
661 all LVS capable nodes regardless of health status.
662 LVS will however never loadbalance traffic to nodes that are BANNED,
663 STOPPED, DISABLED or DISCONNECTED. The "ctdb lvs" command is used to show
664 which nodes are currently load-balanced across.
668 One of the these nodes are elected as the LVSMASTER. This node receives all
669 traffic from clients coming in to the LVS address and multiplexes it
670 across the internal network to one of the nodes that LVS is using.
671 When responding to the client, that node will send the data back
672 directly to the client, bypassing the LVSMASTER node.
673 The command "ctdb lvsmaster" will show which node is the current
678 The path used for a client i/o is thus :
679 <screen format="linespecific">
680 (1) Client sends request packet to LVSMASTER
681 (2) LVSMASTER passes the request on to one node across the internal network.
682 (3) Selected node processes the request.
683 (4) Node responds back to client.
688 This means that all incoming traffic to the cluster will pass through
689 one physical node, which limits scalability. You can send more data to the
690 LVS address that one physical node can multiplex. This means that you
691 should not use LVS if your I/O pattern is write-intensive since you will be
692 limited in the available network bandwidth that node can handle.
693 LVS does work wery well for read-intensive workloads where only smallish
694 READ requests are going through the LVSMASTER bottleneck and the majority
695 of the traffic volume (the data in the read replies) goes straight from
696 the processing node back to the clients. For read-intensive i/o patterns you can acheive very high throughput rates in this mode.
700 Note: you can use LVS and public addresses at the same time.
703 <refsect2><title>Configuration</title>
705 To activate LVS on a CTDB node you must specify CTDB_PUBLIC_INTERFACE and
706 CTDB_LVS_PUBLIC_ADDRESS in /etc/sysconfig/ctdb.
710 You must also specify the "--lvs" command line argument to ctdbd to activete LVS as a capability of the node. This should be done automatically for you by the /etc/init.d/ctdb script.
715 <screen format="linespecific">
716 CTDB_PUBLIC_INTERFACE=eth0
717 CTDB_LVS_PUBLIC_IP=10.0.0.237
724 If you use LVS, you must still have a real/permanent address configured
725 for the public interface on each node. This address must be routable
726 and the cluster nodes must be configured so that all traffic back to client
727 hosts are routed through this interface. This is also required in order
728 to allow samba/winbind on the node to talk to the domain controller.
729 (we can not use the lvs IP address to initiate outgoing traffic)
732 I.e. make sure that you can "ping" both the domain controller and also
733 all of the clients from the node BEFORE you enable LVS. Also make sure
734 that when you ping these hosts that the traffic is routed out through the
740 <refsect1><title>REMOTE CLUSTER NODES</title>
742 It is possible to have a CTDB cluster that spans across a WAN link.
743 For example where you have a CTDB cluster in your datacentre but you also
744 want to have one additional CTDB node located at a remote branch site.
745 This is similar to how a WAN accelerator works but with the difference
746 that while a WAN-accelerator often acts as a Proxy or a MitM, in
747 the ctdb remote cluster node configuration the Samba instance at the remote site
748 IS the genuine server, not a proxy and not a MitM, and thus provides 100%
749 correct CIFS semantics to clients.
753 See the cluster as one single multihomed samba server where one of
754 the NICs (the remote node) is very far away.
758 NOTE: This does require that the cluster filesystem you use can cope
759 with WAN-link latencies. Not all cluster filesystems can handle
760 WAN-link latencies! Whether this will provide very good WAN-accelerator
761 performance or it will perform very poorly depends entirely
762 on how optimized your cluster filesystem is in handling high latency
763 for data and metadata operations.
767 To activate a node as being a remote cluster node you need to set
768 the following two parameters in /etc/sysconfig/ctdb for the remote node:
769 <screen format="linespecific">
770 CTDB_CAPABILITY_LMASTER=no
771 CTDB_CAPABILITY_RECMASTER=no
776 Verify with the command "ctdb getcapabilities" that that node no longer
777 has the recmaster or the lmaster capabilities.
783 <refsect1><title>NAT-GW</title>
785 Sometimes it is desireable to run services on the CTDB node which will
786 need to originate outgoing traffic to external servers. This might
787 be contacting NIS servers, LDAP servers etc. etc.
790 This can sometimes be problematic since there are situations when a
791 node does not have any public ip addresses assigned. This could
792 be due to the nobe just being started up and no addresses have been
793 assigned yet or it could be that the node is UNHEALTHY in which
794 case all public addresses have been migrated off.
797 If then the service status of CTDB depends on such services being
798 able to always being able to originate traffic to external resources
799 this becomes extra troublesome. The node might be UNHEALTHY because
800 the service can not be reached, and the service can not be reached
801 because the node is UNHEALTHY.
804 There are two ways to solve this problem. The first is by assigning a
805 static ip address for one public interface on every node which will allow
806 every node to be able to route traffic to the public network even
807 if there are no public addresses assigned to the node.
808 This is the simplest way but it uses up a lot of ip addresses since you
809 have to assign both static and also public addresses to each node.
811 <refsect2><title>NAT-GW</title>
813 A second way is to use the built in NAT-GW feature in CTDB.
814 With NAT-GW you assign one public NATGW address for each natgw group.
815 Each NATGW group is a set of nodes in the cluster that shares the same
816 NATGW address to talk to the outside world. Normally there would only be
817 one NATGW group spanning the entire cluster, but in situations where one
818 ctdb cluster spans multiple physical sites it is useful to have one
819 NATGW group for each of the two sites.
822 There can be multiple NATGW groups in one cluster but each node can only
823 be member of one NATGW group.
826 In each NATGW group, one of the nodes is designated the NAT Gateway
827 through which all traffic that is originated by nodes in this group
828 will be routed through if a public addresses are not available.
832 <refsect2><title>Configuration</title>
834 NAT-GW is configured in /etc/sysconfigctdb by setting the following
837 <screen format="linespecific">
838 # NAT-GW configuration
839 # Some services running on nthe CTDB node may need to originate traffic to
840 # remote servers before the node is assigned any IP addresses,
841 # This is problematic since before the node has public addresses the node might
842 # not be able to route traffic to the public networks.
843 # One solution is to have static public addresses assigned with routing
844 # in addition to the public address interfaces, thus guaranteeing that
845 # a node always can route traffic to the external network.
846 # This is the most simple solution but it uses up a large number of
847 # additional ip addresses.
849 # A more complex solution is NAT-GW.
850 # In this mode we only need one additional ip address for the cluster from
851 # the exsternal public network.
852 # One of the nodes in the cluster is elected to be hosting this ip address
853 # so it can reach the external services. This node is also configured
854 # to use NAT MASQUERADING for all traffic from the internal private network
855 # to the external network. This node is the NAT-GW node.
857 # All other nodes are set up with a default rote with a metric of 10 to point
858 # to the nat-gw node.
860 # The effect of this is that only when a node does not have a public address
861 # and thus no proper routes to the external world it will instead
862 # route all packets through the nat-gw node.
864 # CTDB_NATGW_NODES is the list of nodes that belong to this natgw group.
865 # You can have multiple natgw groups in one cluster but each node
866 # can only belong to one single natgw group.
868 # CTDB_NATGW_PUBLIC_IP=10.0.0.227/24
869 # CTDB_NATGW_PUBLIC_IFACE=eth0
870 # CTDB_NATGW_DEFAULT_GATEWAY=10.0.0.1
871 # CTDB_NATGW_PRIVATE_NETWORK=10.1.1.0/24
872 # CTDB_NATGW_NODES=/etc/ctdb/natgw_nodes
876 <refsect2><title>CTDB_NATGW_PUBLIC_IP</title>
878 This is an ip address in the public network that is used for all outgoing
879 traffic when the public addresses are not assigned.
880 This address will be assigned to one of the nodes in the cluster which
881 will masquerade all traffic for the other nodes.
884 Format of this parameter is IPADDRESS/NETMASK
888 <refsect2><title>CTDB_NATGW_PUBLIC_IFACE</title>
890 This is the physical interface where the CTDB_NATGW_PUBLIC_IP will be
891 assigned to. This should be an interface connected to the public network.
894 Format of this parameter is INTERFACE
898 <refsect2><title>CTDB_NATGW_DEFAULT_GATEWAY</title>
900 This is the default gateway to use on the node that is elected to host
901 the CTDB_NATGW_PUBLIC_IP. This is the default gateway on the public network.
904 Format of this parameter is IPADDRESS
908 <refsect2><title>CTDB_NATGW_PRIVATE_NETWORK</title>
910 This is the network/netmask used for the interal private network.
913 Format of this parameter is IPADDRESS/NETMASK
917 <refsect2><title>CTDB_NATGW_NODES</title>
919 This is the list of all nodes that belong to the same NATGW group
920 as this node. The default is /etc/ctdb/natgw_nodes.
924 <refsect2><title>Operation</title>
926 When the NAT-GW functionality is used, one of the nodes is elected
927 to act as a NAT router for all the other nodes in the group when
928 they need to originate traffic to the external public network.
931 The NAT-GW node is assigned the CTDB_NATGW_PUBLIC_IP to the designated
932 interface and the provided default route. The NAT-GW is configured
933 to act as a router and to masquerade all traffic it receives from the
934 internal private network and which is destined to the external network(s).
937 All other nodes in the group are configured with a default route of
938 metric 10 pointing to the designated NAT GW node.
941 This is implemented in the 11.natgw eventscript. Please see the
942 eventscript for further information.
947 <refsect2><title>Removing/Changing NATGW at runtime</title>
949 The following are the procedures to change/remove a NATGW configuration
950 at runtime, without having to restart ctdbd.
954 If you want to remove NATGW completely from a node, use these steps:
956 <screen format="linespecific">
957 1, Run 'CTDB_BASE=/etc/ctdb /etc/ctdb/events.d/11.natgw removenatgw'
958 2, Then remove the configuration from /etc/sysconfig/ctdb
962 If you want to change the NATGW configuration on a node :
964 <screen format="linespecific">
965 1, Run 'CTDB_BASE=/etc/ctdb /etc/ctdb/events.d/11.natgw removenatgw'
966 2, Then change the configuration in /etc/sysconfig/ctdb
967 3, Run 'CTDB_BASE=/etc/ctdb /etc/ctdb/events.d/11.natgw updatenatgw'
974 <refsect1><title>NOTIFICATION SCRIPT</title>
976 Notification scripts are used with ctdb to have a call-out from ctdb
977 to a user-specified script when certain state changes occur in ctdb.
978 This is commonly to set up either sending SNMP traps or emails
979 when a node becomes unhealthy and similar.
982 This is activated by setting CTDB_NOTIFY_SCRIPT=<your script> in the
983 sysconfig file, or by adding --notification-script=<your script>.
986 See /etc/ctdb/notify.sh for an example script.
989 CTDB currently generates notifications on these state changes:
992 <refsect2><title>unhealthy</title>
994 This call-out is triggered when the node changes to UNHEALTHY state.
998 <refsect2><title>healthy</title>
1000 This call-out is triggered when the node changes to HEALTHY state.
1004 <refsect2><title>startup</title>
1006 This call-out is triggered when ctdb has started up and all managed services are up and running.
1013 <refsect1><title>ClamAV Daemon</title>
1015 CTDB has support to manage the popular anti-virus daemon ClamAV.
1016 This support is implemented through the
1017 eventscript : /etc/ctdb/events.d/31.clamd.
1020 <refsect2><title>Configuration</title>
1022 Start by configuring CLAMAV normally and test that it works. Once this is
1023 done, copy the configuration files over to all the nodes so that all nodes
1024 share identical CLAMAV configurations.
1025 Once this is done you can proceed with the intructions below to activate
1026 CTDB support for CLAMAV.
1030 First, to activate CLAMAV support in CTDB, edit /etc/sysconfig/ctdb and add the two lines :
1032 <screen format="linespecific">
1033 CTDB_MANAGES_CLAMD=yes
1034 CTDB_CLAMD_SOCKET="/path/to/clamd.socket"
1038 Second, activate the eventscript
1040 <screen format="linespecific">
1041 ctdb enablescript 31.clamd
1045 Third, CTDB will now be starting and stopping this service accordingly,
1046 so make sure that the system is not configured to start/stop this service
1048 On RedHat systems you can disable the system starting/stopping CLAMAV automatically by running :
1049 <screen format="linespecific">
1056 Once you have restarted CTDBD, use
1057 <screen format="linespecific">
1060 and verify that the 31.clamd eventscript is listed and that it was executed successfully.
1069 <refsect1><title>SEE ALSO</title>
1072 <ulink url="http://ctdb.samba.org/"/>
1076 <refsect1><title>COPYRIGHT/LICENSE</title>
1078 Copyright (C) Andrew Tridgell 2007
1079 Copyright (C) Ronnie sahlberg 2007
1081 This program is free software; you can redistribute it and/or modify
1082 it under the terms of the GNU General Public License as published by
1083 the Free Software Foundation; either version 3 of the License, or (at
1084 your option) any later version.
1086 This program is distributed in the hope that it will be useful, but
1087 WITHOUT ANY WARRANTY; without even the implied warranty of
1088 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
1089 General Public License for more details.
1091 You should have received a copy of the GNU General Public License
1092 along with this program; if not, see http://www.gnu.org/licenses/.