Connection Properties

imq.brokerid

String 

None 

Broker identifier 

For brokers using a shared JDBC-based data store, this string is appended to the names of all database tables to identify each table with a particular broker. 

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.

This property is unnecessary for an embedded database or a standalone database which stores data for only one broker instance.  

For enhanced broker clusters (imq.cluster.ha = true), database table names also use the imq.cluster.clusterid property (see Table 17–12).

imq.service.activelist [Must have the same value for all brokers in an enhanced cluster. ]

String 

jms,admin

List of connection services to be activated at broker startup, separated by commas

See Table 6–1 under Configuring Connection Services for the names of the available connection services.

imq.hostname

String 

All available IP addresses

Default host name or IP address for all connection services

imq.portmapper.hostname

String 

None 

Host name or IP address of Port Mapper

If specified, overrides imq.hostname. This might be necessary, for instance, if the broker’s host computer has more than one network interface card installed.

imq.portmapper.port [Can be used with imqcmd update bkr command]

Integer 

7676

Port number of Port Mapper 

If multiple broker instances are running on the same host, each must be assigned a unique Port Mapper port.

imq.serviceName.protocolType.hostname [jms, ssljms, admin, and ssladmin services only; see Appendix C, HTTP/HTTPS Support for information on configuring the httpjms and httpsjms services]

String 

None 

Host name or IP address for connection service

If specified, overrides imq.hostname for the designated connection service. This might be necessary, for instance, if the broker’s host computer has more than one network interface card installed.

imq.serviceName.protocolType.port

Integer 

0

Port number for 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.

imq.portmapper.backlog

Integer 

50

Maximum number of pending Port Mapper requests in operating system backlog 

imq.serviceName.threadpool_model [jms and admin services only]

String 

dedicated

Threading model for thread pool management:  

dedicated: Two dedicated threads per connection, one for incoming and one for outgoing messages




shared: Connections processed by shared thread when sending or receiving messages

The dedicated model limits the number of connections that can be supported, but provides higher performance; the shared model increases the number of possible connections, but at the cost of lower performance because of the additional overhead needed for thread management.  

imq.serviceName.min_threads

Integer 

jms: 10ssljms: 10httpjms: 10 httpsjms: 10 admin: 4ssladmin: 4

Minimum number of threads maintained in connection service’s thread pool 

When the number of available threads exceeds this threshold, threads will be shut down as they become free until the minimum is reached.  

The default value varies by connection service, as shown.  

imq.serviceName.max_threads

Integer 

jms: 1000ssljms: 500httpjms: 500httpsjms : 500admin: 10ssladmin: 10

Number of threads beyond which no new threads are added to the thread pool for use by the named connection service 

Must be greater than 0 and greater than the value of imq.serviceName.min_threads.

The default value varies by connection service, as shown.  

imq.shared.connectionMonitor_limit [Shared threading model only]

Integer 

Solaris: 512Linux: 512Windows: 64

Maximum number of connections monitored by a distributor thread 

The system allocates enough distributor threads to monitor all connections. The smaller the value of this property, the faster threads can be assigned to active connections. A value of -1 denotes an unlimited number of connections per thread.

The default value varies by operating-system platform, as shown.  

imq.ping.interval

Integer 

120

Interval, in seconds, at which to test connection between client and broker 

A value of 0 or -1 disables periodic testing of the connection.