Table 16–11 lists the configuration properties related to broker clusters.
Table 16–11 Broker Properties for Cluster Configuration
Property |
Type |
Default Value |
Description |
---|---|---|---|
imq.cluster.url [Must have the same value for all brokers in a cluster] , [Can be used with imqcmd update bkr command] |
String |
None |
URL of cluster configuration file, if any Examples: http://webserver/imq/cluster.properties (for a file on a Web server) file:/net/mfsserver/imq/cluster.properties (for a file on a shared drive) |
Boolean |
false |
Is broker part of a high-availability cluster? |
|
String |
None |
List of broker addresses belonging to cluster The list consists of one or more addresses, separated by commas. Each address specifies the host name and Port Mapper port number of a broker in the cluster, in the form hostName:portNumber. Example: host1:3000,host2:8000,ctrlhost Note – If set, this property is ignored (and a warning logged) for high-availability clusters; all brokers configured to use the cluster’s shared persistent store are automatically recognized as members of the cluster. |
|
imq.cluster.hostname [Can be specified independently for each broker in a cluster] |
String |
None |
Host name or IP address for cluster connection service If specified, overrides imq.hostname (see Table 16–1) for the cluster connection service. This might be necessary, for instance, if the broker’s host computer has more than one interface card installed. |
Integer |
0 |
Port number for cluster connection service A value of 0 specifies that the port number should be allocated dynamically by the Port Mapper. You might need to set a different value, for instance, to specify a static port number for connecting to the broker through a firewall. |
|
String |
tcp |
Network transport protocol for cluster connection service For secure, encrypted message delivery between brokers, set this property to ssl. |
|
String |
None |
Host name and Port Mapper port number of host on which cluster’s master broker (if any) is running The value has the form hostName:portNumber, where hostName is the host name of the master broker’s host and portNumber is its Port Mapper port number. Example: ctrlhost:7676 Note – enhanced clusters cannot have a master broker. If this property is set for a broker belonging to an enhanced cluster, the broker will log a warning message and ignore the property. |
|
String |
None |
Must be a unique alphanumeric string of no more than n–13 characters, where n is the maximum table name length allowed by the database. No two running clusters may have the same cluster identifier. This string is appended to the names of all database tables in the cluster’s shared persistent store. Note – For brokers belonging to a high-availability cluster, this property is used in database table names in place of imq.brokerid (see Table 16–1). |
|
String |
None |
Host name or IP address for heartbeat service If specified, overrides imq.hostname (see Table 16–1) for the heartbeat service. |
|
Integer |
7676 |
Port number for heartbeat service A value of 0 specifies that the port number should be allocated dynamically by the Port Mapper. |
|
Integer |
2 |
Interval between heartbeats, in seconds |
|
Integer |
3 |
Number of missed heartbeat intervals after which to invoke monitor service |
|
Integer |
30 |
Interval, in seconds, at which to update monitor time stamp Note – Larger values for this property will reduce the frequency of database access and thus improve overall system performance, but at the cost of slower detection and takeover in the event of broker failure. |
|
Integer |
2 |
Number of missed monitor intervals after which to initiate broker takeover |