This chapter includes the following sections.
Topics:
To run the Java Delivery and execute the Java application, you only need an existing Oracle GoldenGate trail file. If the trail file does not contain metadata records, a source definitions file is also required to describe the schema for operations in the trail file. For the examples that follow, a simple TCUSTMER and TCUSTORD trail is used (matching the demo SQL provided with the Oracle GoldenGate software download).
Parent topic: Running Java Delivery
To run Java Delivery using Replicat, simply start the Replicat process from GGSCI:
GGSCI> START REPLICAT javarep GGSCI> INFO REPLICAT javarep
The INFO command returns information similar to the following:
REPLICAT JAVAREP Last Started 2015-09-10 17:25 Status RUNNING
Checkpoint Lag 00:00:00 (updated 00:00:00 ago)
Log Read Checkpoint File ./dirdat/aa0000002015-09-10 17:50:41.000000
RBA 2702
Parent topic: Starting the Application
There are two possible checkpoint files when running with Replicat, the Replicat process checkpoint file and the Java Delivery checkpoint file. Both files are located in the dirchk directory and created using the following naming conventions.
To suppress the creation and use of the Java Delivery checkpoint the Replicat process should be created using the following syntax:
ADD REPLICAT myrep EXTTRAIL ./dirdat/tr NODBCHECKPOINT
It is the NODBCHECKPOINT syntax that disables the creation and use of the Java Delivery checkpoint file.
Parent topic: Running Java Delivery
The checkpoint handling in Replicat is more straightforward as it includes logic to pick which one out of the two checkpoint information is of higher priority. The logic is as follows:
If the Java Delivery is started after user manually performed an ADD or ALTER REPLICAT, then the checkpoint information held by Replicat process will be used as the starting position.
If the Java Delivery is started without prior manual intervention to alter checkpoint (for example, upon graceful stop or an abend), then the checkpoint information held by Java module will be used as the starting position.
For example, restarting a Java Delivery using Replicat at the beginning of a trail looks like the following:
Reset the Replicat to the beginning of the trail data:
GGSCI> ALTER REPLICAT JAVAREP, EXTSEQNO 0, EXTRBA 0
Reset the Replicat
GGSCI> START JAVAREP GGSCI> INFO JAVAREP REPLICAT JAVAREP Last Started 2015-09-10 17:25 Status RUNNING Checkpoint Lag 00:00:00 (updated 00:00:00 ago) Log Read Checkpoint File ./dirdat/aa000000 2015-09-10 17:50:41.000000 RBA 2702
It may take a few seconds for the Replicat process status to report itself as running. Check the report file to see if it abended or is still in the process of starting:
GGSCI> VIEW REPORT JAVAREP
In the case where the Java Delivery is restarted after a crash or an abend, the last position kept by the Java module will be used when the application restarts.
Parent topic: Restarting the Java Delivery