Processing Queues

SSOLite stored procedures write messages to the BG processes using the default background message queues, using a round-robin allocation on a per-session basis. This means that every time a new database session is started the first defined queue (BGMBOX1) is used first. As a result, BGMBOX1 can become overloaded if database sessions are not persisted.

You can override this default behavior for specific transactions by using the SW_SET_QUEUE and SW_UNSET_QUEUE control procedures.

Alternatively, you can dedicate specific message queues to handling requests from your SSOLite stored procedure calls. To do this:

1.

Create a new Mbox set named SSOLITE. (The Mbox set can use either existing message queues or new ones.)

2.

Set the MBSET_WRITE_BG process attribute for your application to assign the SSOLITE1 queue to it. All messages posted to a BG process by the SSOLite stored procedures will now use the SSOLITE Mbox set.

The following example shows a series of commands that you could use to do this.

# Add a new SSOLITEQ1 message queue. (Remember to create the
# table ssolitemboxtable and the ssolitemboxqueue AQ first.)
#
swadm add_queue SSOLITEQ1 Local 0001::ssolitemboxtable:ssolitemboxqueue
# Add a new SSOLITE Mbox set.
#
swadm add_mboxset SSOLITE Local

# Add the SSOLITEQ1 message queue to the SSOLITE Mbox set (6 is the
# Mboxset ID of the SSOLITE Mbox set).
#
swadm add_queue_to_mboxset 6 7
# Set MBSET_WRITE_BG so that calls from the application’s SSOLITE
#stored procedures use the SSOLITE Mbox set to write messages to the 
#BG processes.
#
swadm set_attribute1 SSOLITE 0 MBSET_WRITE_BG 6
#
#Set background processes to read from the queue
#
swadm add_process 1 BG Y
swadm set_attribute 1 BG 5 MBSET_READ_BG 6

Note	The SSOLite stored procedures cache queue information. Therefore, you must shut down and restart all database connections if you change your message queue configuration in this way.

For more information about message queue configuration, see:

•

Mbox Sets and Message Queues.

•

"Administering Message Queues and Mbox Sets" in TIBCO iProcess Engine Administrator's Guide.