IBM Integration Bus, Version 10.0.0.9 Operating Systems: AIX, HP-Itanium, Linux, Solaris, Windows, z/OS


Serialization of input between separate integration nodes on z/OS

This example demonstrates that only one input node at a time takes messages from a shared queue when the same serialization token is used by message flows running on separate integration nodes.

Two integration nodes (MQ01NODE and MQ02NODE) are configured in this example. The respective queue managers are called MQ01 and MQ02. The queue managers participate in the same queue sharing group. Each queue manager has a shared queue INQueue.QSG that has been defined with a disposition of QSG, and a local queue called INQueue. The queue managers can be running in the same Logical Partition (LPAR) or separate LPARs. The Coupling Facility shown in the diagram is a zSeries component that allows z/OS® WebSphere® MQ queue managers in the same system image, or different system images, to share queues.

An identical message flow MyFlowA is deployed to an integration server called MYIntServerA on each integration node. Note that the message flows do not have to be identical; the significant point is that an identical serialization token is used in both flows.

The simple message flow in this example consists of an MQInput node connected to an MQOutput node. The MQInput node in both message flows gets messages from the shared queue INQueue.QSG; the node attribute Serialization Token is configured as MyToken123ABC in both MQInput nodes.

The message flow property additional Instances takes the default value of zero in both message flows, which ensures that input is serialized within the flow.

Illustration showing multiple integration nodes participating in a queue-sharing group
A typical sequence of events for this example follows:
  1. The first integration node MQ01NODE starts and runs message flow MyFlowA in integration server MyGroupA. The input node MyInputNode connects to queue manager MQ01 using a serialization token MyToken123ABC. The input node successfully opens shared queue INQUeue.QSG and gets input messages.
  2. The second integration node MQ02NODE starts and begins to run its copy of message flow MyFlowA in integration server MYIntServerA. The Input node MyInputNode attempts to connect to queue manager MQ02 , also using a serialization token MyToken123ABC.
    The following SDSF console message is logged:
     BIP2656I MQ02NODE MyGroupA 17 UNABLE TO OPEN QUEUE  
     'INQueue.QSG' ON IBM INTEGRATION BUS QUEUE 
     MANAGER 'MQ02': COMPLETION CODE 2; REASON CODE 2271. 
     :ImbCommonInputNode(759) BECAUSE SERIALIZATION TOKEN  
     MyToken123ABC is already in use. NO USER ACTION REQUIRED.   

    Note that this message is output every 30 minutes.

    Message flow MyFlowA in integration server MYIntServerA running on integration node MQ02NODE is unable to process input because the serialization token it has passed is already in use within the queue sharing group. This is indicated by the reason code 2271 (MQRC_CONN_TAG_IN_USE) in message bip2623.

  3. Integration node MQ01NODE stops. Message flow MyFlowA in integration server MYIntServerA in integration node MQ02NODE is now able to get messages from the shared queue INQueue.QSG.
    A sequence of SDSF console messages is logged, of which the following two are relevant:
      BIP2091I MQ02NODE MYIntServerA 17 THE INTEGRATION NODE HAS 
     RECONNECTED TO IBM INTEGRATION BUS 
     SUCCESSFULLY : ImbCommonInputNode(785)               
      BIP9142I MQ01NODE 0 THE COMPONENT HAS STOPPED. : 
     ImbControlService(594)              

The preceding sequence of events also occurs should integration node MQ01NODE fail, rather than stop through a request from the operator, or if a new integration node configuration is deployed to MQ01NODE that deletes or modifies message flow MyFlowA.

This arrangement can also be used where the requirement is to migrate message processing between integration nodes running in different z/OS system images that are attached to the same Coupling Facility.


ae27010_.htm | Last updated 2017-07-17 12:45:25