# All Classes and Interfaces

Class
Description
Announcement
An announcement is the information exchanged by the topology connector and contains all clusters and instances which both the topology connector client and servlet see (in their part before joining the two worlds).
AnnouncementFilter
Filter used during announcement processing internally
AnnouncementRegistry
The announcement registry keeps track of all the announcement that this instance either received by a joined topology connector or that a topology connector inherited from the counterpart (the topology connector servlet)
AnnouncementRegistryImpl
Default implementation of the AnnouncementRegistry which handles JSON-backed announcements and does so by storing them in a local like /var/discovery/impl/clusterNodes/$slingId/announcement.
BaseConfig
Configuration for discovery.base
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.
CachedAnnouncement
With SLING-3389 the Announcement itself doesn't use the created (ie timeout) field anymore (it still has it currently for backwards compatibility on the wire-level) - hence that's why there's this small in-memory wrapper object which contains an Announcement and carries a lastHeartbeat property.
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).
ConnectorRegistry
Registry for topology connector clients
ConnectorRegistryImpl
Default implementation of the ConnectorRegistry which keeps a list of outgoing connectors and is capable of pinging them.
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).
SubnetWhitelistEntry
Implementation of a WhitelistEntry which accepts cidr and ip mask notations.
TopologyConnectorClient
A topology connector client is used for sending (pinging) a remote topology connector servlet and exchanging announcements with it
TopologyConnectorClientInformation
provides information about a topology connector client
TopologyConnectorServlet
Servlet which receives topology announcements at /libs/sling/topology/connector* without authorization (authorization is handled either via hmac-signature with a shared key or via a flexible whitelist)
TopologyRequestValidator
Request Validator helper.
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.
WhitelistEntry
A WhitelistEntry is capable of accepting certain requests depending on a configuration.
WildcardHelper
Helper class for wildcards
WildcardWhitelistEntry
Implementation of a WhitelistEntry which can accept wildcards (* and ?) in both IP and hostname