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starfish77 · Posted: Sun Nov 23, 2003 10:03 pm Post subject: Message and Segments Locking???

I am running 2 processes (2 instances of same application running in their own memory space) which access same queue to retrieve messages .I am using application managed segmentation as the message size is going to be huge. I am not able to lock 1 whole message, meaning ,i want 1 process to access all the segments of 1 logical message. Other process
should not have access to any of the segments, if first process is working on any segments.

If my message queue looks like following, where there are 2 logical messages with 4 segmenets each.

message1seg1
message1seg2
message1seg3
message1seglast
message2seg1
messageseg2
message2seg3
message2seglast

If Process 1 is working on message1seg1, concurrent Process 2 should not be allowed to work on any segment of message1.Rather, it should access message2seg1 and so on.

The problem right now happening is my process 1 works on message1seg1 and process2 works on message1seg2. I am not able to construct the whole message again.

Is there any MQ field I can use to identify message 1 is being worked upon. Will MSGMO_LOCK option help???But i guess it locks
the whole queue, which defeats the purpose of having 2 processes running simulteneously. I am not sure if MatchOptions will solve the problem.

I am using MQ5.3 on AIX.

I will really appreciate any suggestions given.

Thanks,