Sun GlassFish Enterprise Server 2.1 Deployment Planning Guide

HADB Nodes and Machines

Each DRU contains a complete copy of the data in HADB and can continue servicing requests if the other DRU becomes unavailable. However, if a node in one DRU and its mirror in another DRU fail at the same time, some portion of data is lost. For this reason, it is important that the system is not set up so that both DRUs can be affected by a single failure such as a power failure or disk failure.

Note –

Each DRU must run on a completely independent, redundant system.

Follow these guidelines when setting up the HADB nodes and machines:

Caution – Caution –

Do not run nodes from different DRUs on the same machine. If you must run nodes from different DRUs on the same machine, ensure that the machine can handle any single point of failure (for failures related to disk, memory, CPU, power, operating system crashes, and so on).