Java ES Product Components and Zones

Some of the objectives discussed in Why Use Zones for Java ES? for using Java ES in a multi-zone environment, and the usage scenarios they imply, make use of the propagation capabilities of the global zone to simplify life-cycle management of Java ES product components. Such usage scenarios, for example, call for life-cycle management of Java ES product components to be performed in the global zone by the global administrator, while the configuration and runtime management of those components is performed in non-global zones by zone administrators.

In other words, product components would be installed and upgraded in the global zone, but instances would be configured and run in non-global zones. This usage scenario would combine the benefits of centralized life-cycle management with the isolation and security afforded by non-global zones.

This scenario, however, depends upon the ability of each product component to be installed in the global zone, but be configured and run in a non-global zone. This separation depends upon how configuration of each product component is achieved, where configuration and dynamic application data is stored, how configuration data is located by executing binaries, and how upgrades are performed. For example separation might depend upon what pre or post install or upgrade scripts do: whether they start or stop component instances, set up links to configuration data, or perform other tasks that blur the distinction between life-cycle and configuration management.

This separation can also depend upon whether configuration is performed in a whole root or sparse root zone. For example, if a product component's configuration script writes to a read-only file system in a sparse root zone (for example /usr) or if non-default file systems (such as /opt) are shared with a sparse root zone, then the configuration of a component can fail.

Nearly all Java ES product components are installed under /opt, which by default, is writable in sparse root zones. For more information, see Sun Java Enterprise System 5 Installation Reference for UNIX

At the current time, the ability of each of the roughly 20 Java ES product components to support the separation of life-cycle management and configuration/runtime management between global and non-global zones has not been established. The various product components have adopted different approaches to configuration and upgrade. Given this situation, propagation of Java ES product components (except for Message Queue) is not currently supported. For more information, see Java ES Propagation Policies.