MetadataUpdater Contract

Table 1. MetadataUpdater Contract
Method	Description
`close`	`void close()` Closes the metadata updater
`fetchNodes`	`List<Node> fetchNodes()` Used when: `NetworkClient` is requested to leastLoadedNode `DefaultMetadataUpdater` (of `NetworkClient`) is requested to isAnyNodeConnecting
`handleCompletedMetadataResponse`	`void handleCompletedMetadataResponse( RequestHeader requestHeader, long now, MetadataResponse metadataResponse)` Handles a response to a metadata request Used when `NetworkClient` is requested to handle a completed MetadataResponse
`handleDisconnection`	`void handleDisconnection( String destination)` Used when `NetworkClient` is requested to disconnect, close, and processDisconnection
`handleFatalException`	`void handleFatalException( KafkaException fatalException)` Used when `NetworkClient` is requested to doSend and processDisconnection
`isUpdateDue`	`boolean isUpdateDue( long now)` Used when `NetworkClient` is requested to isReady
`maybeUpdate`	`long maybeUpdate( long now)` Starts a cluster metadata update if needed and possible. Used when `NetworkClient` is requested to read and write to sockets.
`requestUpdate`	`void requestUpdate()` Schedules an update of the current cluster metadata Used when `NetworkClient` is requested to handleTimedOutRequests, handleDisconnections and establish a connection to a broker node

Table 2. MetadataUpdaters
MetadataUpdater	Description
AdminMetadataUpdater	Used by AdminMetadataManager
DefaultMetadataUpdater	Default `MetadataUpdater` of NetworkClient
ManualMetadataUpdater	Used by ControllerChannelManager, TransactionMarkerChannelManager, KafkaServer and ReplicaFetcherBlockingSend

MetadataUpdater