Service Quality Components

In addition to the system service components shown in Table 1–1, Java ES includes a number of components used to enhance the quality of services provided by system service components. Service quality components can also enhance custom-developed application services. The service quality components fall into the following categories:

• Availability components

• Access components

• Monitoring components

Availability Components

Availability components provide near-continuous uptime for system service components and custom application services. The availability components included in Java ES and the services they provide are shown in the following table. For more details on each component, see Availability Components.

Table 1–2 Java ES Availability Components

Component	Availability Services Provided
High Availability Session Store	Provides a data store that makes application data, especially session state data, available even in the case of failure.
Sun Cluster	Provides high availability and scalability services for Java ES, the applications that run on top of the Java ES infrastructure, and the hardware environment in which both are deployed.
Sun Cluster Geographic Edition [Java ES 5 is the first release to include Sun Cluster Geographic Edition as a Java ES product component.]	Protects applications from unexpected disruptions using multiple clusters that are geographically separated and a redundant infrastructure that replicates data between these clusters. Sun Cluster Geographic Edition software is a layered extension of Sun Cluster software.

Access Components

Access components provide front-end access to system services, often secure access from Internet locations outside an enterprise firewall. In addition to providing such access, many provide a routing and caching function as well. The access components included in Java ES and the services they provide are shown in the following table. For more details on each component, see Access Components.

Table 1–3 Java ES Access Components

Component	Access Services Provided
Sun Java System Portal Server (includes Secure Remote Access)	Provides secure, Internet access from outside a corporate firewall to Portal Server content and services, including internal portals.
Sun Java System Web Proxy Server	Provides for caching, filtering, and distribution of web content for both outgoing and incoming Internet requests.

Monitoring Components

Java ES includes a new monitoring feature that provides real-time system status and customizable monitoring jobs. Monitoring is implemented by the Sun Java System Monitoring Console product component, which is supported by the Sun Java System Monitoring Framework shared component. For more information, see Monitoring Components.