Task Failover and Load Balancing

Using MCS, you can configure a task failover and load-balancing environment for your applications, to safeguard important task operations from server downtime and to more evenly distribute the workload across the network.

In a load-balanced environment, the total amount of work is divided across multiple run-time servers so that the work is done more efficiently and, in general, users are served faster. Multiple requests for a task are run on a series of run-time servers in a pre-determined order. This provides support for more concurrent users and means that you don't have to designate a specific server to run each task.

Only stateless task failover is supported. In a stateless environment, a single task runs to completion before another task is started. Tasks that are linked to other tasks in your project are not maintained in a failover situation; however, you can specify a login task when you configure your session pools.

The following types of task interface objects can be used in your client applications:

Task failover and load balancing is different from MCS server failover and load balancing, which affects all MCS services and data. For information about failover protection for MCS server clusters, see Managing MCS Servers and Clusters, Overview.

Error Reporting

To report failed connections, you must enable event logging. All failed connections are reported to your event log in MCS. For details, see Configuring Synapta Services Builder Event Logging.

Note To successfully implement failover and load-balancing use either a non-application server environment, such as when using task beans and task files (XML), or use either WebLogic or SunONE as your application server. Failover and load-balancing errors may occur when using the J2EE connector with WebSphere and Oracle.

To use SunONE, modify the security.policies file in the application server to support inbound pocket connections. Because the service agent is local, you can limit the requests to "localhost".

grant {
    permission java.net.SocketPermission "localhost:1024-","accept, connect, listen";

Currently, when using WebSphere and Oracle, the resource adapter hangs when attempting to establish contact with MCS service agent.

Related Topics
Bullet Associating Tasks with Run-time Servers, Overview
Bullet Managing MCS Servers and Clusters, Overview
Bullet Configuring Synapta Services Builder Event Logging
Bullet Associating Tasks with Agent Clusters