We are pleased to announce Liberty Collectives, introduced with WebSphere Application Server V8.5.5. The Liberty Collective is the new multi-server administrative domain designed exclusively for the WebSphere Application Server Liberty Profile. A Liberty Collective extends the Liberty management model provided in WebSphere Application Server V8.5 by enabling servers to be grouped together into a “collective”.
The Liberty administrative domain
A Liberty collective consists of two types of entities: controllers and members.
Collective controllers are the new administrative servers in the collective topology. A controller serves as a control point for other servers in the collective, providing MBeans which provide collective operations. A controller also behaves like a member. Controller capabilities are enabled with some configuration actions and the collectiveController-1.0 feature.
Collective members are entities within the collective which publish information about themselves to a controller. A server becomes a collective member through some configuration actions and enabling the collectiveMember-1.0 feature.
The collective controller and member functions are enabled with Liberty features, and can therefore be combined with any other features supported by the Liberty runtime – this means any server which is either a collective member or a controller can also host applications, serve applications and perform other business needs.
Liberty Systems Management in 8.5.5 is…
- Automated – Less input is required to establish a secure configuration.
- Faster – No profile management tool; instead there is a simpler-to-use command-line tool set.
- Easier – Easier to script as functions are consistently command-line enabled.
- Self-contained – Servers can be zipped up, moved to new location, and joined to a collective quickly.
- Agent-less – No node agents. This means there is less cost on system resources to enable centralized management.
- Decentralized – The master copy of a server’s configuration is owned by that server.
It is important to understand that a Liberty collective is not a cluster; there is an important distinction. A collective is a formal grouping used to facilitate centralized administration of Liberty profile servers. It does not by itself provide clustering.