We are piloting a new product called Transaction Vision, which captures all MQ API calls on the platforms it is installed on. This product is actually very interesting to use. One can see how various MQ applications are actually coded and what they do behind the scenes.
What we have seen watching MQSI is that when a new Flow is turned on, the buffer it initially specifies for the MQGET is 3732. The MQGMO Options MQSI is using are: MQGMO_WAIT|MQGMO_SYNCPOINT|MQGMO_FAIL_IF_QUIESCING|MQGMO_LOGICAL_ORDER|MQGMO _COMPLETE_MSG It uses this buffer size until it gets a message bigger than 3732, at which point the MQGET fails with a 2080. MQSi then redoes the MQGET with a buffer upped to the size of the message it just tried to MQGET. If that message was 5040 bytes for instance, this flow is now using 5040 bytes for all subsequent GETs, until something bigger than 5040 comes in. The problem is, the time between the first MQGET on the to big message which fails to the time the second MQGET with the larger buffer is sometimes up to 1.5 seconds. This kills our front end app, which has a 2000 millisecond wait time. Granted, this is not a big problem, because MQSI keeps the larger buffer, so the longer this flow runs, the less often we have the 2080 errors. But where did it get that 3732 size in the first place? And when does the buffer get dropped back to this #? When the broker is stopped maybe? We have noticed that this 3732 # is used for all flows in all execution groups, and simply stopping/starting the flow does not reset it. MQSI Version 2.1 CSD2 Peter Potkay IBM MQSeries Certified Specialist, Developer [EMAIL PROTECTED] X 77906 This communication, including attachments, is for the exclusive use of addressee and may contain proprietary, confidential or privileged information. If you are not the intended recipient, any use, copying, disclosure, dissemination or distribution is strictly prohibited. If you are not the intended recipient, please notify the sender immediately by return email and delete this communication and destroy all copies. Instructions for managing your mailing list subscription are provided in the Listserv General Users Guide available at http://www.lsoft.com Archive: http://vm.akh-wien.ac.at/MQSeries.archive
