[WDSCI-L] queue polling problem resolved

["Wolf de, Jeroen" <j.dewolf@xxxxxxxxx>]

Hi,

I am happy to announce that the polling problem is as good as solved.

My previous mail:

>>Hi,

>>I have a web app that needs to be controlled from an iSeries dataque. The 
>>iSeries sends control messages on a dataqueue on >>end and start of day and 
>>my webapp reads the messages from the queue in a polling thread, reading with 
>>a wait of -1. 
>>Whenever a message appears, the webapps status should switch to STOPPED, 
>>STOPPING, or RUNNING. 
>>The problem is that some of the messages seem to disappear. It looks like 
>>they are retrieved from the queue but not 
>>processed. The behaviour is unpredictable, sometimes the thread handles the 
>>message correctly after sending repeated 
>>control messages and the webapp responds correctly. For instance, I have to 
>>send 3 or more repeated STOP messages until the 
>>thread responds.
>>Can someone tell me how a robust polling mechanism should be implemented, so 
>>that every control message is handled?

>>Kind regards,

>>Jeroen de Wolf

To share my solution with fellow programmers:

It appears that writing a message to a keyed dataqueue with a key of 24 * 0 is 
retrieved somehow by an internal job on the iSeries (@#$!!^#@^#??!!) 
Writing a message 23*0 and a 1 on the end leaves the message on the queue for 
my WebSphere application.

Kind regards,

Jeroen de Wolf