Reverting with Enterprise Replication

If you use Enterprise Replication, you must complete replication-related tasks when you revert from the new version of Informix®.

Before you begin

Prerequisites:

  • Perform all reversion operations as user informix.
  • Enterprise Replication must be running, or you must delete the replication server before you revert.
  • All servers in the Enterprise Replication domain must be available.
  • Replication queues must be nearly empty.

About this task

During reversion to an earlier version of Informix® with Enterprise Replication:
  • Master replicates become standard replicates and tables that were added to the sysscdr database are removed.
  • Tables that are created with templates are dropped.
  • The table that contains replicated table-version information, which was created during conversion, is dropped.

If you are reverting from version 11.70.xC3 or a later version to version 11.70.xC1 or 11.70.xC2, you do not need to follow the additional Enterprise Replication migration procedures that are described in this topic.

If you want to revert to a version earlier than when Enterprise Replication was defined on this server, you must remove Enterprise Replication from this server before reverting. After you remove Enterprise Replication, you can revert your server using the instructions at Reverting from Informix Version 15.0.

Procedure

To revert from Version 15.0 with Enterprise Replication:
  1. Release or remove any grid statements that are deferred from propagation by running the ifx_grid_release() or ifx_grid_remove() function.
  2. Stop applications that are doing replicable transactions.
  3. Remove Enterprise Replication features from the current release that cannot be reverted. For more information, see ids_mig_084.html.
  4. Run the onstat -g cat repls command to check whether if Enterprise Replication is in alter mode. If so, run the cdr alter --off command.
  5. Delete shadow replicates.
  6. Run cdr stop to shut down Enterprise Replication.
  7. Make sure that control and TRG send queues are empty:
    • Run onstat -g grp to ensure that the Enterprise Replication grouper does not have any pending transactions.
    • Run onstat -g rqm to check for queued messages.
  8. Shut down Enterprise Replication with the following command: 
    cdr stop
  9. Perform database server reversion tasks, as described in Reverting from Informix Version 15.0.
  10. Run onmode -l and onmode -c to prevent the database server from failing when you start Enterprise Replication.
  11. After reversion completed and old version started successfully, start Enterprise Replication by running the cdr start command. When reverting to a version prior to version 15.x.x.x, use cdr cleanstart instead to avoid the log snooper reading the newer version's log files.