| |
|
RSS Feed - WebSphere MQ Support
|
RSS Feed - Message Broker Support
|
| Disappearing messages (between S390 & AIX) |
« View previous topic :: View next topic » |
| Author |
Message
|
| jc_squire |
 Posted: Wed Aug 07, 2002 1:28 pm Post subject: |
 |
|
Centurion
Joined: 14 Apr 2002
Posts: 105
Location: New Zealand
|
Also, if you use a qmgr on another platform (anything other than OS390) to connect to QM1 do you still have the same problem?
Regards
_________________
J C Squire
IBM Certified Specialist - MQSeries |
|
| Back to top |
|
 |
| Sunntu |
| Posted: Wed Aug 07, 2002 7:33 pm Post subject: Disappearing messages |
|
|
Novice
Joined: 04 Aug 2002
Posts: 11
|
Hi,
Thanks for the input. I cant wait to test the same.
Our test plan is something like this:
I am not sure whether I said this in my earlier mail, the whole set up works fine under normal conditions. By normal, I mean that the channels are running fine at both ends, the qmgrs are fine and the conection is also fine.
We are designing this whole set up for a bank and they were very particular that their messages are not lost when there is some network connectivity problem or any other problem.
Our first test was to stop the sender channel and run the program which places persistent messages. Then start the channel and see if it reaches the destination. Well, this is where we started and this is where we still are.
One more point, you were right, the messages that I thought I lost have reappeared on the XMITQ since the channel has been stopped. So after all we have not lost the messages.
I will test based on the steps you have given and get back with the results.
Rgds,
Sunntu |
|
| Back to top |
|
|
| jc_squire |
| Posted: Wed Aug 07, 2002 7:53 pm Post subject: |
|
|
Centurion
Joined: 14 Apr 2002
Posts: 105
Location: New Zealand
|
Ok, even though the messages have re-appeared on your xmitq you should still resolve the chls and check sequence nrs to make sure there are no messages indoubt otherwise you will be back at square one.
This certainly looks like a tcp/ip issue on your network so if I were you I would definitely get the network guys to monitor the network during the testing.
Good luck !!!!
_________________
J C Squire
IBM Certified Specialist - MQSeries |
|
| Back to top |
|
|
| Sunntu |
| Posted: Thu Aug 08, 2002 1:35 am Post subject: Disappearing messages - lost and found |
|
|
Novice
Joined: 04 Aug 2002
Posts: 11
|
Hi JC,
Good news. I followed the whole set of steps that you had put out in your mail. And here are my results:
1. Persistent messages are not lost. They either reappear in the XMITQ or if the sender managed to deliver to the receiver then it was found in SYSTEM.CLUSTER.TRANSMIT.QUEUE if it was not delivered to the destination.
2. During this transmit process if the sender is abruptly stopped due to some reason, it looks as if the sender and the receivers go out of sync. and have to be resolved by manual intervention.
Just resolve with backout was not enough. We had to also reset the sequence numbers on both sides.
3. Once this was done, the whole set up started behaving normally. Persistent messages were all delivered to the destination.
In our set up the S390 QMGR and the AIX cluster QMGR are going to be miles apart. I do not expect the channel to be down every other day but we now know where to look for the messages if something goes wrong and how to get the set/up working again without losing messages.
I guess the TCP/IP error came up since the sender and receiver channels were not in SYNC.
My inferences may not be right, am just a child when it comes to MQ, but resolve with reset definitely put things back on track. And I have tested this many times since morning.
Roger, if the XMITQ did not have defpsist(yes) then the whole set up behaved rather wierdly. Some reached the destination and some did not. Setting to DEFPSIST - YES was also quite important in getting the whole thing working.
Just one question, do such problems arise whenever a remote qmgr is concerned or is this something special in S390 or is there something wrong in our set up ? And never once did any message go into the DLQ !!!
Thanks a lot for all the inputs.
Regards
Sunntu |
|
| Back to top |
|
|
| jc_squire |
| Posted: Thu Aug 08, 2002 2:29 pm Post subject: |
|
|
Centurion
Joined: 14 Apr 2002
Posts: 105
Location: New Zealand
|
Glad to hear that things are working out.
1. Were you able to determine why the messages were sitting on the SYSTEM.CLUSTER.TRANSMIT.QUEUE and not delivering to the destination?
2. How are you stopping the sender? In a controlled stop you should not have any problems with indoubt messages and sequence numbers.
3. As it should 
If sequence numbers go out of sync channels will go into retry, and in the error logs it will specifically say that the sequence numbers are out of sync. This problem will not report a tcp/ip error because in fact there is no tcp/ip error - it is a mq error. Also, the problems you are experiencing are happening before the seq nrs go out of sync - resolving a chl is what causes the seq nr sync problem e.g. AIX host sent a commit to OS390 for msg #5 (so sequence nr on AIX will be 5) but OS390 did not receive the commit (causing the symptoms you are experiencing), when you resolve the channel msg #5 is rolled back on OS390 and the sequence number on OS390 is then 4 while on AIX it is 5.
What you are experiencing is not acceptable or normal mq behaviour. Your problems are symptoms of a network issue and you will continue having these problems until your network issues are sorted. By resolving the chls and resetting seq nrs you are treating the symptoms and not the cause. As I mentioned before, we had a similar problem connecting to a trading partner in Australia and it took something like 6 weeks and many frustrating hours to eventually find the problem but once it was fixed we have never had to backout the queues or reset the channels again - it has been over a year now (touch wood).
The fact that no messages went to the DLQ proves that your queue/chl config is all setup correctly.
Only pleased to be able to assist  .
Regards
_________________
J C Squire
IBM Certified Specialist - MQSeries |
|
| Back to top |
|
|
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
|
|
|
|
