1. Developing SOA Applications with Oracle SOA Suite
  2. Using the Oracle Mediator Service Component
  3. Resequencing in Oracle Mediator
  4. Resequencing Order
  5. FIFO Resequencer
  6. Example of the FIFO Resequencer

Example of the FIFO Resequencer

Table 23-3 illustrates the behavior of the FIFO resequencer where msgX(Y,Z) indicates that the message arrives as message number X to the Mediator service component and the message contains sequenceID Y and group Z.

Table 23-3 FIFO Resequencer Behavior

Incoming Messages Sequenced Messages

msg12(4,c)

msg05(9,a)

msg02(7,a)

msg10(3,c)

msg10(3,a)

msg07(5,a)

msg06(1,c)

msg03(2,c)

msg12(4,c),msg10(3,c),msg06(1,c),msg03(2,c)

msg05(9,a), msg02(7,a), msg10(3,a), msg07(5,a)

As shown in Table 23-3, the messages are sequenced based on their time of arrival and the sequenceID is not used for sequencing.

Note:

When using the FIFO resequencer, use a single-threaded inbound adapter to avoid unpredictable results. For example, when you use the file/FTP adapter, the database adapter, or the AQ adapter in front of a Mediator service component that is configured as a FIFO resequencer, configure the adapter for single-threaded processing. Otherwise, unpredictable results occur because the arrival time of each message is calculated when the message arrives to the Mediator service component instead when it arrives to the adapter service.