Configuring the storage of events for Resequence nodes

You can use a Resequence configurable service to control the storage of events for Resequence nodes.

About this task

Information about the state of in-flight messages is held on storage queues that are controlled by WebSphere® MQ, so you must install it on the same computer as your integration node if you want to use the capabilities provided by the Resequence node. The storage queues that hold the state information are owned by the queue manager that is associated with the integration node, and you specify this queue manager by using the -q property of the mqsicreatebroker command; see mqsicreatebroker command.

If the integration node has the necessary permissions to create the default system queues, they are created automatically when a flow containing Resequence nodes is deployed. If the default queues are not created automatically, you can create them manually; see Creating the default IBM Integration Bus queues on a WebSphere MQ queue manager.

By default, the storage queues used by all Resequence nodes are:

SYSTEM.BROKER.EDA.EVENTS
SYSTEM.BROKER.EDA.COLLECTIONS

These queues are also used by the Collector node.

However, you can control the queues that are used by different Resequence nodes by creating alternative queues that contain a QueuePrefix variable, and by using a Resequence configurable service to specify the names of those queues for storing events.

Follow these steps to specify the queues that are used to store event states, and to set the timeout and the start and end of the sequence:

Procedure

Create the storage queues to be used by the Resequence node.
The following queues are required:
- SYSTEM.BROKER.EDA.QueuePrefix.EVENTS
- SYSTEM.BROKER.EDA.QueuePrefix.COLLECTIONS
The QueuePrefix variable can contain any characters that are valid in a WebSphere MQ queue name, but must be no longer than eight characters and must not begin or end with a period (.). For example, SET1 and SET.1 are valid queue prefixes, but .SET1 and SET1. are invalid.

If you do not create the storage queues, IBM Integration Bus creates the set of queues when the node is deployed; these queues are based on the default queues. If the queues cannot be created, the message flow is not deployed.
Use the mqsicreateconfigurableservice command to create a Resequence configurable service. You can create a configurable service to be used with either a specific sequence or with all sequences in an integration server.
1. If you are creating a configurable service to be used with a specific sequence, ensure that the name of the configurable service is the same as the name that you specify in the Configurable service property on the Resequence node. If you are creating a configurable service to be used with all sequences in the integration server, ensure that the configurable service has the same name as the integration server. However, the name of a configurable service cannot start with a digit; if the name of the configurable service is to be the same as that of the integration server, ensure that the name of the integration server does not start with a digit.
2. Set the Queue prefix property to the required value.
3. Optional: Set the Missing message timeout, Start of sequence, and End of sequence properties.
For example, create a Resequence configurable service called myResequenceService, which uses queues prefixed with SYSTEM.BROKER.EDA.SET1, with a missing message timeout of 60 seconds, and which waits five seconds before determining the start and end numbers in a sequence:
```
mqsicreateconfigurableservice MYBROKER -c Resequence -o myResequenceService 
-n queuePrefix,missingMessageTimeoutSeconds,startSequenceSeconds,endSequenceSeconds -v SET1,60,5,5 
```
You can use the mqsideleteconfigurableservice command to delete the Resequence configurable service. However, the storage queues are not deleted automatically when the configurable service is deleted, so you must delete them separately.
For more information, see Configurable services properties
In the Resequence node:
1. If the configurable service is to be used for a specific sequence, specify the name of the configurable service on the Advanced tab; for example, myResequenceService.
  If you do not set the Configurable service property, and if a configurable service exists with the same name as the integration server, that configurable service is used instead.
2. Optional: Use the mqsichangeproperties and mqsireportproperties commands to change or view the properties of the configurable service.
  Alternatively, you can use the web user interface to view or modify a configurable service.

What to do next

The properties for the configurable service are not used by the integration node until you restart or redeploy the message flow, or restart the integration node.