|
| |
It is always good to understand the terminology of ShaoLin HA Cluster prior install the system.
A cluster is one or more hosts who performs a similar goal with cooperative internode communication messages.
One of the host(member hosts) inside the cluster. Cluster node and cluster member will be used and is referred to the same entity.
A cluster key is a randomly generated number which stores in a file. A cluster group will only have a single unique cluster key for identification.
A heartbeat is kind of message send out by the cluster member periodically to tell other cluster members that it is alive. If don't receive heartbeat message from a member for a period of time, this node will be treat as dead, other cluster member will takeover the resource groups that it is owning. The heartbeat can be serial channel or Ethernet channel.
Communication Channel is a group of heartbeat with same heartbeat type.
A resource can be shared by the nodes inside the application failover domain, such as storage, IP address. An application may have several resources, and before the node can run this application, it should first get all the resources own by the application.
A member owning a resource means it allows the application running on that member to access those resources. A member who owns the resource may also activate or deactivate the resource.
A resource group is a set of resources, that provide certain kind of service to user. And these resource have dependencies. And a resource group is treat as one entity, exclusive resources will only be owned by one cluster member at one time, and share resources will allow to own by multiple members in the failover domain.
A failover domain is a set of nodes that can own the resource group, and when the resource inside the resource group fail, it will failover the one of these node according to the order of failover domain.
Share resource means the resources can be shared among one or more cluster members in the failover domain.