Recoverable OTMA transactions

The recoverability of OTMA-initiated transactions and commands is determined by several factors.

The factors include:
  • Is it a recoverable or unrecoverable transaction?
  • Is it a recoverable or unrecoverable command?
  • Is the recoverable sequence number 0 (zero) or not?
  • Is it a synchronized or nonsynchronized transaction pipe?
  • Is it Commit Mode 0 (commit-then-send) or Commit Mode 1 (send-then-commit)?

A recoverable IMS transaction submitted using the send-then-commit transaction flow is not rejected. However, send-then-commit transactions are discarded during IMS restart (they are unrecoverable).

Transactions that use synchronized transaction pipes are recoverable. Input messages are not recoverable for send-then-commit transactions, and requesting an ACK message has no effect on whether a transaction is recoverable. You should request ACK messages for proper synchronization of the synchronized transaction pipe.

Also, when a transaction reaches IMS, its recoverability depends on how it is defined to IMS.