# Package org.apache.sling.discovery.base.commons

@Version("2.0.1") package org.apache.sling.discovery.base.commons
Provides some common classes for discovery implementors that choose to extend from discovery.base

Version:
  1.1.0

Class
Description
BaseDiscoveryService
Abstract base class for DiscoveryService implementations which uses the ClusterViewService plus Topology Connectors to calculate the current TopologyView
BaseViewChecker
The heartbeat handler is responsible and capable of issuing both local and remote heartbeats and registers a periodic job with the scheduler for doing so.
ClusterViewHelper
Contains some static helper methods around ClusterView
ClusterViewService
The ClusterViewService is capable of determining the ClusterView of the local cluster (ie of the instances that are all hooked to the same underlying repository).
DefaultTopologyView
Default Implementation of the topology view interface
PeriodicBackgroundJob
Simple executor of a background job that periodically invokes a particular runnable - catching RuntimeExceptions that might throw - but not catching Errors (that terminates the BackgroundJob).
UndefinedClusterViewException
This exception is thrown when the ClusterViewService does not have a cluster view that is valid.
UndefinedClusterViewException.Reason
ViewChecker
A ViewChecker is capable of issuing a heartbeat and subsequently checking the resulting, current view in the local cluster.