Running amqsfhac to test message integrity

Run the IBM MQ MQI client sample program amqsfhac in parallel with amqmfsck to demonstrate that a queue manager maintains message integrity during a failure.

Before starting

You require four servers for this test. Two servers for the multi-instance queue manager, one for the file system, and one for running amqsfhac as a IBM MQ MQI client application.

Follow step 1 in Verify shared file system behavior on Multiplatforms to set up the file system for a multi-instance queue manager.

The IBM MQ MQI client sample program amqsfhac checks that a queue manager using networked storage maintains data integrity following a failure. Run amqsfhac in parallel with amqmfsck to demonstrate that a queue manager maintains message integrity during a failure.

Procedure

1. Create a multi-instance queue manager on another server, QM1, using the file system you created in step 1 in Procedure. See Create a multi-instance queue manager.
2. Start the queue manager on both servers making it highly available. On server 1:

   strmqm -x QM1
   

   On server 2:

   strmqm -x QM1
   

3. Set up the client connection to run amqsfhac.
   1. Use the procedure in Verify an IBM MQ installation for the platform, or platforms, that your enterprise use to set up a client connection, or the example scripts in Reconnectable client samples.
   2. Modify the client channel to have two IP addresses, corresponding to the two servers running QM1. In the example script, modify:

      DEFINE CHANNEL(CHANNEL1) CHLTYPE(CLNTCONN) TRPTYPE(TCP) +
      CONNAME('LOCALHOST(2345)') QMNAME(QM1) REPLACE
      

      To:

      DEFINE CHANNEL(CHANNEL1) CHLTYPE(CLNTCONN) TRPTYPE(TCP) +
      CONNAME('server1(2345),server2(2345)') QMNAME(QM1) REPLACE
      

      where server1 and server2 are the host names of the two servers, and 2345 is the port that the channel listener is listening on. Usually this defaults to 1414. We can use 1414 with the default listener configuration.

4. Create two local queues on QM1 for the test. Run the following MQSC script:

   DEFINE QLOCAL(TARGETQ) REPLACE
   DEFINE QLOCAL(SIDEQ) REPLACE
   

5. Test the configuration with amqsfhac

   amqsfhac QM1 TARGETQ SIDEQ 2 2 2
   

6. Test message integrity while we are testing file system integrity.
   • Run amqsfhac during step 5 of Verify shared file system behavior on Multiplatforms.

   amqsfhac QM1 TARGETQ SIDEQ 10 20 0
   

   If you stop the active queue manager instance, amqsfhac reconnects to the other queue manager instance once it has become active. Restart the stopped queue manager instance again, so that we can reverse the failure in your next test. You will probably need to increase the number of iterations based on experimentation with the environment so that the test program runs for sufficient time for the failover to occur.

Results

An example of running amqsfhac in step 6 is shown in the following example. In this example, the test is a success.

Sample AMQSFHAC start
qmname = QM1
qname = TARGETQ
sidename = SIDEQ
transize = 10
iterations = 20
verbose = 0
Iteration 0
Iteration 1
Iteration 2
Iteration 3
Iteration 4
Iteration 5
Iteration 6
Resolving MQRC_CALL_INTERRUPTED
MQGET browse side tranid=14 pSideinfo->tranid=14
Resolving to committed
Iteration 7
Iteration 8
Iteration 9
Iteration 10
Iteration 11
Iteration 12
Iteration 13
Iteration 14
Iteration 15
Iteration 16
Iteration 17
Iteration 18
Iteration 19
Sample AMQSFHAC end

If the test detected a problem, the output would report the failure. In some test runs MQRC_CALL_INTERRUPTED might report Resolving to backed out. It makes no difference to the result. The outcome depends on whether the write to disk was committed by the networked file storage before or after the failure took place.

Parent topic: Requirements for shared file systems on Multiplatforms

Related information

• amqmfsck (file system check)
• High availability sample programs