You can change the queue block size without restarting Replication Server .
The queue block size is the number of bytes in a contiguous
block of memory used by stable queue structures. In Replication Server 15.5, you can increase the queue block size from the default of 16KB to 32KB, 64KB, 128KB, or 256KB to enhance replication performance. Performance improvement is also dependent on the transaction profile and the environment. However, in version 15.5 you must restart Replication Server for the change in queue block size to take effect. In version 15.6, you need not restart Replication Server for the change in in queue block size to take effect.
Note: You must have the Advanced Services Options license, named REP_HVAR_ASE, to use the increased queue block size feature.
Recommendations
Sybase strongly recommends that you:
- Verify you have sufficient memory before you increase the queue block size.
- Experiment with different queue block sizes to determine the optimum value for your replication system.
Restrictions
- Make sure that there is no data flowing into Replication Server while the queue block size change is in progress.
- You cannot change the queue block size while a subscription is being materialized, if dematerialization is in progress, or if routes are being created or destroyed. The queue block size change terminates with an error message while Replication Server continues operating.
- Once you start the procedure to change the queue block size, Replication Server does not accept another command to change the queue block size until the first change is completed.
- Do not use any other procedures to change the queue block size in the RSSD directly, as these procedures may result in inconsistencies in the queue block size configuration and cause Replication Server to shut down.
Note: All queues are drained after the block size changes.