Listener dies and data lost in Java

[peteeide]

We have an issue where we send data from MQ to another application using Java. However, the data gets backed up in the application (cannot process as fast as Java tries to put), I assume in the buffer. Last week as well as a couple of months ago the listener died while Java was trying to put data and some records were lost. I know MQ guarantees data integrity but probably only going from MQ to MQ. Is this data recoverable or does the listener need to be shut down and restarted every so often for some reason? Any help is appreciated. Thanks

 

[mqonnet]

MQ Guarantees but only to the extent as MQ is responsible. You got to use SYNCPOINT so that messages are put under control(transaction). Also bear in mind, if TCP/IP somehow messes it up, then MQ may not be held responsible. But otherwise, there is very scanty chance that your data be lost when using syncpointing.



Cheers
KK

 

[pmeekin]

Agree entirely with KK but would just add that you need to make sure that you have made your data 'safe' before you commit the MQGET. E.g. if you get a message, commit and then due to some delay in processing your app dies before you've written it to wherever it needs to go then you've lost your message for good. If you want to make sure you never lose a message think of the MQ bit as being only part of the overall transaction.

Cheers,
Paul