Running the active and standby synchronization services allows you to use the daemon on the standby server to continue running jobs when the daemon on the active server fails. Because these services keep the repositories on the active and standby servers synchronized, the standby server is used as the failover.
Mention of nn.nn in any filepath refers to the major and minor version numbers of Data Mover.
| Name | Description |
|---|---|
| Original-active | The system primarily used as the active system before failover occurred. Also referred to as the failed active or restored active, depending on the state of the system. |
| Designated-standby | The standby system assigned to take responsibility as the active system if the original-active stops working. Also referred to as the designated new active. |
| Standby-only | A standby system that remains as a standby in case of failure, unlike the designated-standby, which becomes the active system during failure. Multiple standby-only systems may be present. |
- Wait for the designated-standby synchronization service to finish running all the SQL statements on the standby server. This can be confirmed by waiting a few minutes and then checking if the dmSyncSlave.json file is being regenerated. Upon failure in the standby synchronization system, this file might not get removed.
- If the synchronization system on the designated-standby is still running, stop the service on the server by running, /opt/teradata/datamover/sync/nn.nn/dmsync stop, where nn.nn refers to the major and minor version numbers of Data Mover .
- On the designated-standby, edit the sync.properties file and set sync.isMaster to true, so the designated-standby acts as the active server.
- Remove the following files if found in the log directory.
- dmSyncMaster.json
- slave_<clientName>.lastread
- dmSyncSlave.json
- slave_sql.lastExecuted
- metricsCollectorPointer.txt
- Run /opt/teradata/datamover/sync/nn.nn/dmsync start to start the active synchronization service for the new designated active server (designated-standby).
- Run /opt/teradata/datamover/sync/nn.nn/dmsync stop for any remaining standby-only servers that are synchronized with the failed original-active.
- For each of the remaining standby-only systems, edit the value of master.host in sync.properties to reflect the host name of the designated new active server (designated-standby).
- Run /etc/init.d/dmdaemon start to restart the daemon on the designated new active server (designated-standby).
- Enable the synchronization service on the designated-standby while acting as the active system during failure by running the teradata/datamover/sync/nn.nn/dmsync start command.For more information, see Starting the Synchronization Service.
- Run /opt/teradata/datamover/sync/nn.nn/dmsync start for the remaining standby-only servers to restart the synchronization service.
- On the machine where the command-line interface is installed, modify the value for dm.rest.endpoint in the commandline.properties with the designated-standby REST server URL.
- If you have the Data Mover portlet installed in your environment, click Data Mover Setup in the Admin menu in the Teradata Viewpoint portal to enable monitoring of the designated-standby Data Mover server.