A leading brokerage firm located in the Midwestern U.S. needed to implement data replication to provide a redundant active/backup HPE NonStop Server system for a “sizzling-hot-takeover” in the event of a primary system failure.
Shadowbase Solution – Active/Almost Active Backup Disaster Recovery:
- In this configuration, the active and backup nodes are identically configured with active bi-directional replication used to maintain synchronism between the two databases.
- However, though the applications are active on both nodes, client interactions (broker requests) are only directed to the primary node.
- In the event that the primary node fails or is taken offline, routers switch the clients to the other node within a sub-second time frame.
- Since the application is already active (up and running and waiting for requests) on the backup node, takeover is virtually instantaneous and imposes very little impact on user processing.
- It is impossible to tell which node is the primary node and which is the backup node. They are both identically configured, with all processes active at all times.
- To test the system’s fail-over capability, management often forces a router switch to reverse the nodes.
- It is extremely important in a fail-over architecture to actually test the disaster recovery plan to make sure that it works, ensure that the disaster recovery plan stays up-to-date, and that the operations staff is well-versed in the process.
Additional Shadowbase Benefit – Avoiding Planned Outages:
- The brokerage firm also takes advantage of off-loading queries and reporting from the active node, which makes it extremely easy to avoid planned outages due to the need to upgrade a node.
- When such an upgrade is needed, the router feed is switched to the other node, replication to the downed node is stopped, and the upgrade is performed.