Missing MSMQ message although it is there

Question

I have a web app that drop service request onto the msmq via wcf. The wcf service class is configure to have maximum of 1, ie only 1 instance of the class processing the request at any given time. There instances where 3 service request is submitted but we only see 1 msmq message in the queue with 1 message being currently process by the wcf service class. 1 msmq message is perceive missing as we do not see the msmq message in the msmq monitoring snap-in. But however all 3 service request is executed in the end. What is the cause of this and what is the best way to have a consistent and accurate monitoring.

Answer 1

The MSMQ Snap-in is pretty slow for this and you often need to execute a Refresh manually. I simply guess that the messages are processed more quickly than you can follow them with the snap-in.

My suggestion is to implement your own monitoring app. John Opincar wrote a nice article with sample code about it: Counting Messages in an MSMQ MessageQueue from C#

This was the base for rolling own own Message Queue Monitor that is still used on our production systems.