Sun GlassFish Enterprise Server 2.1 Deployment Planning Guide

Repository

Management agents store the database configuration in a repository. The repository is highly fault-tolerant, because it is replicated over all the management agents. Keeping the configuration on the server enables you to perform management operations from any computer that has a management client installed.

A majority of the management agents in a domain must be running to perform any changes to the repository. Thus, if there are M agents in a domain, at least M/2 + 1 agents (rounded down to a whole number) must be running to make a change to the repository.

If some of the hosts in a domain are unavailable, for example due to hardware failures, and you cannot perform some management commands because you don’t have a quorum, use the hadbm disablehost command to remove the failed hosts from the domain.