Automatic failover is supported when two Data Mover clusters are configured in an active-standby configuration. To enable automatic failover, two additional monitoring severs are required to monitor the active and standby components. The services perform the following functions:
- The monitoring service uses SSH connections to monitor the designated-active (or primary) components to see if services are running, including the sync monitor.
- The sync monitor makes sure that the Data Mover repositories are in synchronization by monitoring Postgres replication between the active and standby servers.
A failover sequence is initiated when any of the following designated-active components are unavailable:
- Daemon
- Repository
- Agents
- REST service
- ActiveMQ
As part of the failover process, the following occurs:
- Active components stop
- Standby components start
- Monitoring service for the designated-active components stop
- Monitoring service on designated-standby components start
See the Teradata® Data Mover Installation, Configuration, and Upgrade Guide for Customers, B035-4102 for information on the following DSA restrictions and related configurations:
- Enabling failover for jobs using the DSA utility, pre-configuring BAR NCs for the standby DSC environment (applicable regardless of database version).
- Pre-configuring source and target databases using Teradata systems version 16.00 or later for the standby DSC environment.
- Configuring source and target Teradata databases with version 16.00 or earlier when the active and standby Data Mover daemons are using the bundled DSC setup. When using multiple DSC environments to run jobs, you must reconfigure DSMAIN each time you want to run the same job after a Data Mover failover occurs.