The list consists of one or more addresses, separated by commas. Each address specifies (or implies) the host name, port number, and connection service for a broker instance to which the client can connect. Address syntax varies depending on the connection service and port assignment method; see below for details.

Literal IP addresses as host names: You can use a literal IPv4 or IPv6 address as a host name. If you use a literal IPv6 address, its format must conform to RFC2732, Format for Literal IPv6 Addresses in URL's.

• PRIORITY: Order specified in address list

• RANDOM: Random order

A value of -1 denotes an unlimited number of iterations.

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

A value of -1 denotes an unlimited number of connection attempts: attempt repeatedly to connect to first address until successful. For example, in an enhanced broker cluster, this value will allow for connection to the failover broker.

This value applies both for successive attempts on a given address and for successive addresses in the list.

This value applies when connecting to the port mapper as well as when connecting to the required service.

The timeout value 0 (zero) denotes an infinite timeout, in which case the connection will block until it is established or an error occurs.

If false, the Message Queue client runtime will validate all certificates presented to it. Validation will fail if the signer of the certificate is not in the client's trust store.

If true, validation of certificates is skipped. This can be useful, for instance, during software testing when a self-signed certificate is used.

NOTE: To use signed certificates from a certification authority, set this attribute to false.

The address list entry specifies the host name and port number for the Message Queue Port Mapper. The Port Mapper itself dynamically assigns a port to be used for the connection.

Default values:

• hostName = localhost

• portNumber = 7676

• serviceName = jms

For the ssljms connection service, all variables must be specified explicitly.

Literal IP addresses as host names: You can use a literal IPv4 or IPv6 address as a host name. If you use a literal IPv6 address, its format must conform to RFC2732, Format for Literal IPv6 Addresses in URL's.

Bypasses the Port Mapper and makes a TCP connection directly to the specified host name and port number.

Bypasses the Port Mapper and makes a secure SSL connection directly to the specified host name and port number.

If multiple broker instances use the same tunnel servlet, the following syntax connects to a specific broker instance rather than a randomly selected one:

http://hostName:portNumber/contextRoot/tunnel?

• ServerName=hostName:instanceName

Makes an HTTP connection to a Message Queue tunnel servlet at the specified URL. The broker must be configured to access the HTTP tunnel servlet.

If multiple broker instances use the same tunnel servlet, the following syntax connects to a specific broker instance rather than a randomly selected one:

https://hostName:portNumber/contextRoot/tunnel?

• ServerName=hostName:instanceName

Makes a secure HTTPS connection to a Message Queue tunnel servlet at the specified URL. The broker must be configured to access the HTTPS tunnel servlet.

If the connection is aborted, the Message Queue Client Runtime operates as though the connection to the broker were broken.

A value of 0 denotes no timeout (wait indefinitely).

Delivery of payload messages to the client is temporarily suspended after this number of messages, allowing any accumulated control messages to be delivered. Payload message delivery is resumed on notification by the client runtime, and continues until the count is again reached.

A value of 0 disables metering of message delivery and may cause Message Queue control messages to be blocked by heavy payload message traffic.

Message delivery on a connection stops when the number of unconsumed payload messages pending (subject to flow metering governed by imqConnectionFlowCount) exceeds this limit. Delivery resumes only when the number of pending messages falls below the limit. This prevents the client from being overwhelmed with pending messages that might cause it to run out of memory.

This attribute is ignored if imqConnectionFlowLimitEnabled is false.

When set to false, message prefetching and buffering is disabled, and each consumer is delivered one message at a time, which can give rise to a number of performance issues.

This property should be set to false only when business logic demands that each consumer have only one message at a time.

Message delivery to a given consumer stops when the number of unconsumed payload messages pending for that consumer exceeds this limit. Delivery resumes only when the number of pending messages for the consumer falls below the percentage specified by imqConsumerFlowThreshold. This can be used to improve load balancing among multiple consumers and prevent any single consumer from starving others on the same connection.

A value of 0 or -1 denotes an unlimited number of messages.

This limit can be overridden by a lower value set for a queue’s own consumerFlowLimit attribute (see Chapter 18, Physical Destination Property Reference). Note also that message delivery to all consumers on a connection is subject to the overall limit specified by imqConnectionFlowLimit.

A value of 0 denotes no timeout (wait indefinitely).

This value is ignored if the imqAbortOnPingAckTimeout attribute is set to false.

If false, the client will load only a single message at a time.

This attribute applies only to JMS application server facilities.

1 Nonpersistent

2 Persistent

A value of 0 denotes an unlimited expiration time (message never expires).