The communication between the DCS agent and the DCS manager is based on TCP connections. The DCS agent makes a TCP connection to the DCS manager and sends data and gets a response. The DCS agent then closes the connection. The current protocol used over the TCP connection is either HTTP or more commonly HTTPS. When using the HTTPS protocol, the DCS agent verifies the server certificate by matching it with the copy of the certificate that is installed in the agent's keystore. Because the mechanism the agent uses does not use the IP addresses of the agent or server , multiple managers share the same certificate and the agent can communicate equally well with any manager.
DCS agents are registered with the database and not with a DCS manager. The DCS manager just allows the agent to interact in a controlled way with the database. The DCS manager does not keep state information.
Since the agent - manager communication is stateless, each connection from an DCS agent can be routed to any DCS manager.
Here we introduce a method to implement load balancing for DCS manager.
There are two DCS managers that share the same database:
The DCS agent will connect to the secondary manager if the primary one down.
Here are the steps of the installation and configuration:
1. Install the first DCS manager and DCS console in server1, and backup these three configuration files: agent-cert.ssl, server.xml and server-cert.ssl:
2. Copy these three configuration files to server2
3. Install DCS manager and DCS console in server2
4. Uninstall DCS manager in server2:
DON'T uninstall the DCS console
5. Run setup.exe to reinstall DCS manager in server2, and select 'Install Tomcat component ONLY':
6. Select the three configuration files accordingly which copy from server1 in step 2:
7. The server1 and server2 will share the same communication cert file and share the same database
8. During the installation of the DCS agent, input the primary server and secondary server accordingly:
9. After the DCS agent installed, you can run sisipsconfig -v to check the DCS server that the agent registered and connected:
10. There is a Failback Interval which the DCS agent will connect to the secondary manager if the primary one is down. The default interval is 60 minutes. Also you can run sisipsconfig -forcereg to force the DCS agent to re-register. The below screenshot shows re-register to the secondary server after the primary one is down:
