Sun Cluster Geographic Edition System Administration Guide

Analyzing the Application for Suitability

This section describes the guidelines you must follow in creating applications to be managed by Sun Cluster Geographic Edition software.

Before you create an application to be managed by Sun Cluster Geographic Edition software, determine whether the application satisfies the following requirements for being made highly available or scalable.

Note –

If the application fails to meet all requirements, modify the application source code to make it highly available or scalable.

A scalable service must meet all the preceding conditions for high availability as well as the following additional requirements.

For a scalable service, application characteristics also determine the load-balancing policy. For example, the load-balancing policy Lb_weighted, which allows any instance to respond to client requests, does not work for an application that makes use of an in-memory cache on the server for client connections. In this case, you should specify a load-balancing policy that restricts a given client's traffic to one instance of the application. The load-balancing policies Lb_sticky and Lb_sticky_wild repeatedly send all requests by a client to the same application instance, where they can make use of an in-memory cache. If multiple client requests come in from different clients, the RGM distributes the requests among the instances of the service.

See Chapter 2, Developing a Data Service, in Sun Cluster Data Services Developer’s Guide for Solaris OS for more information about setting the load-balancing policy for scalable data services.

The application must be able to meet the following data replication requirements: