Maintaining the sequential order of messages

You can maintain the order in which messages enter a message flow by using the Sequence and Resequence nodes.

Before you begin

Read the concept topic about Message sequencing.

About this task

When messages have been processed in a message flow, they might be propagated in a different order to the order in which they arrived at the input node, so the original message sequence can be altered. You can use the Sequence and Resequence nodes to rearrange the messages into sequential order based on a sequence number in the message, restoring the original sequence in which they entered the input node.

If the messages contain sequence numbers, you can use the Resequence node to re-establish the order in which they arrived at the input node. If the messages do not contain sequence numbers, you can use a Sequence node to apply sequence numbers to the messages, before reordering them into sequential order using the Resequence node.

Procedure

  • If the messages contain sequence numbers, rearrange the messages into sequential order by creating a message flow containing a Resequence node. See Reordering messages in a message flow.
  • If the messages do not contain sequence numbers, establish the sequential order of the messages by completing the following steps:
    1. Create a message flow containing a Sequence node, which you can use to apply sequence numbers to the messages. See Adding sequence numbers to messages.
    2. Create a message flow containing a Resequence node, which you can use to re-establish the sequential order of the messages. See Reordering messages in a message flow.