1 This directory is where you should put any local or application
2 specific event scripts for ctdb to call.
4 All event scripts start with the prefic 'NN.' where N is a digit.
5 The event scripts are run in sequence based on NN.
6 Thus 10.interfaces will be run before 60.nfs.
8 Each NN must be unique and duplicates will cause undefined behaviour.
9 I.e. having both 10.interfaces and 10.otherstuff is not allowed.
12 As a special case, any eventscript that ends with a '~' character will be
13 ignored since this is a common postfix that some editors will append to
14 older versions of a file.
17 The eventscripts are called with varying number of arguments.
18 The first argument is the "event" and the rest of the arguments depend
19 on which event was triggered.
21 All of the events except the 'shutdown' and 'startrecovery' events will be
22 called with the ctdb daemon in NORMAL mode (ie. not in recovery)
24 The events currently implemented are
26 This event does not take any additional arguments.
27 This event is only invoked once, when ctdb is starting up.
28 This event is used to wait for the service to start and all
29 resources for the service becoming available.
31 This is used to prevent ctdb from starting up and advertize its
32 services until all dependent services have become available.
34 All services that are managed by ctdb should implement this
35 event and use it to start the service.
37 Example: 50.samba uses this event to start the samba daemon
38 and then wait until samba and all its associated services have
39 become available. It then also proceeds to wait until all
40 shares have become available.
43 This event is called when the ctdb service is shuting down.
45 All services that are managed by ctdb should implement this event
46 and use it to perform a controlled shutdown of the service.
48 Example: 60.nfs uses this event to shut down nfs and all associated
49 services and stop exporting any shares when this event is invoked.
52 This event is invoked every X number of seconds.
53 The interval can be configured using the MonitorInterval tunable
54 but defaults to 15 seconds.
56 This event is triggered by ctdb to continously monitor that all
57 managed services are healthy.
58 When invoked, the event script will check that the service is healthy
59 and return 0 if so. If the service is not healthy the event script
60 should return non zero.
62 If a service returns nonzero from this script this will cause ctdb
63 to consider the node status as UNHEALTHY and will cause the public
64 address and all associated services to be failed over to a different
67 All managed services should implement this event.
69 Example: 10.interfaces which checks that the public interface (if used)
70 is healthy, i.e. it has a physical link established.
73 This event is triggered everytime the node takes over a public ip
74 address during recovery.
75 This event takes three additional arguments :
76 'interface' 'ipaddress' and 'netmask'
78 Before this event there will always be a 'startrecovery' event.
80 This event will always be followed by a 'recovered' event once
81 all ipaddresses have been reassigned to new nodes and the ctdb database
83 If multiple ip addresses are reassigned during recovery it is
84 possible to get several 'takeip' events followed by a single
87 Since there might involve substantial work for the service when an ip
88 address is taken over and since multiple ip addresses might be taken
89 over in a single recovery it is often best to only mark which addresses
90 are being taken over in this event and defer the actual work to
91 reconfigure or restart the services until the 'recovered' event.
93 Example: 60.nfs which just records which ip addresses are being taken
94 over into a local state directory and which defers the actual
95 restart of the services until the 'recovered' event.
99 This event is triggered everytime the node releases a public ip
100 address during recovery.
101 This event takes three additional arguments :
102 'interface' 'ipaddress' and 'netmask'
104 In all other regards this event is analog to the 'takeip' event above.
109 This event is triggered everytime we start a recovery process
110 or before we start changing ip address allocations.
113 This event is triggered every time we have finished a full recovery
114 and also after we have finished reallocating the public ip addresses
117 Example: 60.nfs which if the ip address configuration has changed
118 during the recovery (i.e. if addresses have been taken over or
119 released) will kill off any tcp connections that exist for that
120 service and also send out statd notifications to all registered
124 This event is called when a node is STOPPED and can be used to
125 perform additional cleanup that is required.
126 Note that a stopped node is considered inactive, so it will not
127 be issuing the recovered event once the cluster has recovered.
128 See 91.lvs for a use of this event.
130 Additional note for takeip, releaseip, recovered:
132 ALL services that depend on the ip address configuration of the node must
133 implement all three of these events.
135 ALL services that use TCP should also implement these events and at least
136 kill off any tcp connections to the service if the ip address config has
137 changed in a similar fashion to how 60.nfs does it.
138 The reason one must do this is that ESTABLISHED tcp connections may survive
139 when an ip address is released and removed from the host until the ip address
141 Any tcp connections that survive a release/takeip sequence can potentially
142 cause the client/server tcp connection to get out of sync with sequence and
143 ack numbers and cause a disruptive ack storm.