Automate BPA Server Agent Failover

 

INTRODUCTION
Automate BPA Server provides “failover” capability for continuous availability and reliability. Failover is the ability for an Agent to automatically switch over to a standby Automate BPA Server upon failure or abnormal termination of the previously active server component.

REQUIREMENTS
Automate BPA Server failover relies on the following conditions in order to function properly:
1. Two Automate BPA Server components and at least one Agent.
2. One external database back end is in use as the BPA data store for both Server components.

CONCEPT
The failover functionality is primarily Agent-based in that remote Agents are responsible for communicating with the server and are able to connect to a secondary or tertiary server if the primary server connection is lost. This is performed independent of the BPA Server. The Agents can be configured for up to three server hostnames (or IP addresses) to allow a hierarchal order of primary, secondary and tertiary servers. The different hostnames are stored in the registry under a single key value separated by semi-colons. The Agent will always attempt to connect to the primary hostname first. If that is not available, the secondary, then tertiary server will be attempted. This process will cycle until the agent successfully connects to a server.

If the Agent connects to the primary server, and the connection to that server is lost, the agent shall set a timer for fifteen (15) seconds and attempt to connect to secondary and then tertiary servers as described above.

If the Agent connects to a secondary or tertiary server, a timer for thirty (30) seconds is set. When the timer expires, a separate thread is started to test if the primary server is available. If it is, the connection is closed and the Agent reconnects to the primary server.

INSTRUCTIONS
1. Shutdown the Agent service.
2. Create a backup of the registry.
3. Based on the version of BPA installed, go to the following registry location and edit the Host string:
32bit (x86) application / 32bit (x86) operating system or 64bit (x64) application / 64bit (x64) operating system:
- BPA7: HKEY_LOCAL_MACHINE\SOFTWARE\Network Automation\BPA Agent\TaskService\Agent
- BPA8: HKEY_LOCAL_MACHINE\SOFTWARE\Network Automation\BPA Agent 8\TaskService\Agent
- BPA9: HKEY_LOCAL_MACHINE\SOFTWARE\Network Automation\Automate BPA Agent 9\TaskService\Agent
- BPA10: HKEY_LOCAL_MACHINE\SOFTWARE\Automate\Automate BPA Agent 10\TaskService\Agent
32bit (x86) application / 64bit (x64) operating system:
- BPA7: HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Network Automation\BPA Agent\TaskService\Agent
- BPA8: HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Network Automation\BPA Agent 8\TaskService\Agent
- BPA9: HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Network Automation\Automate BPA Agent 9\TaskService\Agent
- BPA10: HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Automate\Automate BPA Agent 10\TaskService\Agent
4. Enter the primary, secondary and tertiary server name or IP address followed by the port and separating each with a semi colon. For example (correct port numbers are provided):
- BPA7: servername1:7100;servername2:7100;servername3:7100
- BPA8: servername1:8500;servername2:8500;servername3:8500
- BPA9: servername1:9500;servername2:9500;servername3:9500
- BPA10: servername1:9600;servername2:9600;servername3:9600
5. Exit the registry.
6. Restart the Agent Service.

Repeat the above instructions for all relevant Agent machines.

CONCLUSION
Automate BPA Server’s failover functionality is an ideal backup operation that automatically switches to a standby server if the primary system fails or is temporarily shut down. Failover is an important fault tolerance function of mission-critical systems that rely on constant accessibility due to its ability to redirect requests from the failed or down system to the backup system that mimics the operations of the primary system.

Applies To: Automate BPA Server 7, Automate BPA Server 8, Automate BPA Server 9, Automate BPA Server 10