NonStop JMS User's Manual (H06.03+, J06.03+, NonStop JMS 3.0+)

NSJMS and JMS Client Applications

NonStop Server for Java Message Service User’s Manual—522356-006

4-8

Destination Names

Queue names and topic names are Java letters and Java digits, limited to 100 bytes,

where the first character is a Java letter. This syntax also describes subscription

names and client IDs.

Temporary Destinations

JMS allows for the creation of temporary queues and topics that exist only for the

duration of a JMS connection. A temporary queue or topic is a unique destination that

survives only as long as the JMS connection that created it. NSJMS creates these as

specially named destinations with these prefixes: __temp_queue__ or __temp_topic__.

When a JMS connection is closed, any temporary destinations along with associated

messages are removed. If an application ends abnormally and a close operation is

not performed, the temporary destinations and associated messages remain on the

database until the next DELETE MESSAGE EXPIRED operation is performed.

This code fragment creates a temporary queue destination:

Queue queue = session.createTemporaryQueue();

This code fragment creates a temporary topic destination:

Topic topic = session.createTemporaryTopic();

Destination IDs

Destinations (queues and topics) within NSJMS are assigned IDs that represent the

destinations in the database. The IDs allow efficient storage for messages and flexible

partitioning of the message table.

Assignment of the destination ID is done when the destination is first created. This

assignment can be automatic (implicit) or it can be explicitly provided within the

administrative commands.

Explicit destination-ID assignment is useful when you need message-table partitioning.

The IDs are chosen so that ranges are defined over the IDs to identify the partitions.

For example, you can group destinations by 100s with separate partitions assigned to

each range of 100.

Destination IDs must be positive numbers, 1 to 32767 (SHORT_MAX). If no explicit

ID is specified, the ID is generated by adding one to the current highest ID. Destination

IDs cannot be changed once assigned. You must delete and re-create a destination to

change an ID.

Persistence

NSJMS does not optimize for NON_PERSISTENT messages (deliver at most once). All

messages are treated as having PERSISTENT delivery mode (deliver once and only

once).