Management & Control Services (MCS) can be installed on multiple servers across your network, creating a server cluster. Installing an MCS server cluster, rather than just a standalone MCS server, provides server scalability, failover protection, and the capability to provide load balancing. Load balancing requires additional third-party network hardware or software.
Benefits of server clustering include:
|All servers in your cluster must run on the same Web application server and under the same operating system. In addition, you must specify the same configuration options (for example, port numbers) for each server installation and you must install the same MCS management components on all servers in the cluster.|
To create a server cluster, you install two or more MCS servers. You can make the servers part of a cluster either at the time of installation, or later, through the MCS console.
One of the servers in your cluster acts as the primary server. All configuration changes take place through the cluster's primary server. When you publish data, such as session configurations and presentations to MCS, you should publish to the primary server. Data is dynamically replicated across all servers in the cluster, ensuring that all active servers have access to the latest data. If the primary server ever goes off-line, the server with next highest priority in the cluster takes over primary server responsibilities.
Although you can access the MCS console from another server in the cluster just as you do from the primary server, the console request is automatically redirected to the primary server. When you contact other servers in the cluster for purposes other than MCS console access, for example, to access session configurations or presentations, the request is not redirected. In some environments, having users access data from the most convenient server in the cluster can reduce network traffic.
Servers in a cluster should be started one at a time in priority order, beginning with the primary server. Each server gets the most up-to-date data from the primary server when it is started.
Some clients make use of the MCS agent to communicate with MCS; others communicate directly. The agent is installed at the same time as the client itself is installed, if an agent does not already exist on the client computer. Otherwise, the existing agent, detected during installation, is used. The agent communicates with MCS through an assigned server in the cluster. If that server goes down, the agent finds another server in the cluster and directs future communication through it.
|When components that do not use the MCS agent, such as Presentation Integrator, attempt to communicate with an MCS server that is not running, the connection will fail unless there is a third-party load balancing solution in place.|
In MCS, you can create clusters of agents; however, they are not used by EXTRA! X-treme or Terminal Viewers.
|EXTRA! Mainframe Server Edition Overview|
|Data Replication and Failover Protection|
|Viewing Server Information|