
Chapter 17
Clustering
17.1 Introduction
This chapter defines the terms and concepts used when clustering Rhino SLEE and describes several typical configurations.
Various scenarios within the cluster such as bootstrap, failure and recovery are explained within the context of the typical
clustered installation.
The Rhino SLEE is a distributed system in that it runs across multiple computers connected via an IP network. A Rhino SLEE
cluster is managed as a single system image and is an N-way active cluster architecture as opposed to an active-standby design.
17.2 Concepts and terms
Rhino SLEE uses a number of terms and concepts to describe its clustering features. Each of the terms is described and the
relationship between the terms is shown within the context of a typical installation.
17.2.1 Cluster Node
Each cluster node is a separate process with a unique identifier termed the node ID. There may be several nodes on the same
machine. It is typical in a Network Critical Physical Infrastructure model that each node is installed on a single host computer.
Each node is able to execute management commands, execute SBBs, and host Resource Adaptors and Profiles.
17.2.2 Quorum Node
A quorum node is a lightweight cluster node which only exists for determining cluster membership in the event of network
segmentation or node failures. It does not perform any event processing, cannot host resource adaptors, and cannot be the target
of management operations. In effect, it cannot perform any work.
17.2.3 Cluster
A cluster is a collection of nodes. Each cluster has a unique identifier termed the cluster ID. Each node can be a member of
one cluster only. The set of nodes in a cluster are discovered at runtime and does not need to be configured a priori. The set of
nodes can expand and contract over time without taking the cluster offline.
17.2.4 Cluster Membership
Cluster membership is defined as the set of nodes that the cluster membership algorithm decides are reachable within a timeout
period.
100
Kommentare zu diesen Handbüchern