NonStop JMS User's Manual (H06.03+, J06.03+, NonStop JMS 3.0+)
NonStop Server for Java Message Service User’s Manual—522356-006
5-1
5 Reliable Messaging Bridge
Introduction
The reliable messaging bridge is hosted on the NonStop platform and sits between a
locally hosted JMS client library from a foreign JMS provider and the NSJMS JMS API.
Using the standard Sun Microsystems JMS API, the reliable messaging bridge reads
from a locally hosted foreign JMS provider and writes to NSJMS, or reads from NSJMS
and writes to a locally hosted foreign JMS provider. Figure 5-1 on page 5-2 illustrates
the components used in a reliable messaging bridge along with the flow of information.
The bridge moves messages reliably using persistent processes and transactions.
Within each process, reliability is achieved by enclosing the movement of messages
between a locally hosted foreign JMS provider and NSJMS in JMS transacted
sessions. In the event of an unrecoverable error, the bridge will roll back any messages
transferred during the transaction.
Persistence is achieved by using Pathway. Messages can be batched together and
moved in a single transaction which improves throughput performance. The batch size
is specified during bridge pathway configuration. Durable subscriptions are supported
for source topics, and both source queue and topics may specify selectors in their
configurations. Each bridge is composed of one or more processes that are managed
to assure they are restarted after failures. For queues, multiple processes may be
defined, whereas topics may only have a single process per topic.
The reliable messaging bridge components included in the installation of NSJMS in the
/usr/tandem/nsjms/version/bridge directory, where version is the vproc of
this RVU (for example, T1251V30_30SEP2003_V30) are:
btool.sh – This script invokes the configuration tool. The configuration tool maps
between queues and topics and defines the persistent environment parameters.
(For more information, see Configure a Reliable Messaging Bridge on page 5-2.)
start_template.txt – This file is used by the configuration tool to generate an
executable Pathway start script.
stop_template.txt – This file is used by the configuration tool to generate an
executable Pathway start script.