# Package org.apache.solr.cloud

Classes for dealing with ZooKeeper when operating in SolrCloud mode.

See: Description

- Interface Summary
  Interface | Description
  --- | ---
  ActionThrottle.NanoTimeSource |
  OverseerMessageHandler | Interface for processing messages received by an `OverseerTaskProcessor`
  OverseerMessageHandler.Lock |
  OverseerTaskProcessor.OverseerMessageHandlerSelector | An interface to determine which `OverseerMessageHandler` handles a given message.
  RecoveryStrategy.RecoveryListener |

- Class Summary
  Class | Description
  --- | ---
  ActionThrottle |
  AddReplicaCmd |
  Assign |
  BackupCmd |
  CloudConfigSetService |
  CloudDescriptor |
  CloudUtil |
  CreateAliasCmd |
  CreateCollectionCmd |
  CreateShardCmd |
  CreateSnapshotCmd | This class implements the functionality of creating a collection level snapshot.
  CurrentCoreDescriptorProvider | Provide the current list of registered `CoreDescriptor`s.
  DeleteAliasCmd |
  DeleteCollectionCmd |
  DeleteNodeCmd |
  DeleteReplicaCmd |
  DeleteShardCmd |
  DeleteSnapshotCmd | This class implements the functionality of deleting a collection level snapshot.
  DistributedMap | A distributed map.
  DistributedQueue | A distributed queue.
  ElectionContext |
  LeaderElector | Leader Election process.
  LeaderInitiatedRecoveryThread | Background daemon thread that tries to send the REQUESTRECOVERY to a downed replica; used by a shard leader to nag a replica into recovering after the leader experiences an error trying to send an update request to the replica.
  LockTree | This is a utility class that offers fine grained locking for various Collection Operations This class is designed for single threaded operation.
  MigrateCmd |
  Overseer | Cluster leader.
  Overseer.FailedOp |
  Overseer.Stat |
  Overseer.Stats | Used to hold statistics about overseer operations.
  OverseerAutoReplicaFailoverThread | In this simple initial implementation we are limited in how quickly we detect a failure by a worst case of roughly zk session timeout + WAIT_AFTER_EXPIRATION_SECONDS + WORK_LOOP_DELAY_MS and best case of roughly zk session timeout + WAIT_AFTER_EXPIRATION_SECONDS.
  OverseerCollectionConfigSetProcessor | An `OverseerTaskProcessor` that handles: 1) collection-related Overseer messages 2) configset-related Overseer messages
  OverseerCollectionMessageHandler | A `OverseerMessageHandler` that handles Collections API related overseer messages.
  OverseerConfigSetMessageHandler | A `OverseerMessageHandler` that handles ConfigSets API related overseer messages.
  OverseerNodePrioritizer | Responsible for prioritization of Overseer nodes, for example with the ADDROLE collection command.
  OverseerRoleCmd |
  OverseerSolrResponse |
  OverseerStatusCmd |
  OverseerTaskProcessor | A generic processor run in the Overseer, used for handling items added to a distributed work queue.
  OverseerTaskQueue | A `DistributedQueue` augmented with helper methods specific to the overseer task queues.
  OverseerTaskQueue.QueueEvent |
  RecoveryStrategy |
  ReplaceNodeCmd |
  RestoreCmd |
  SizeLimitedDistributedMap | A size limited distributed map maintained in zk.
  SolrZkServer |
  SplitShardCmd |
  SyncStrategy |
  ZkCLI |
  ZkController | Handle ZooKeeper interactions.
  ZkSolrResourceLoader | ResourceLoader that works with ZooKeeper.
  ZkSolrResourceLoader.ZkByteArrayInputStream |

- Exception Summary
  Exception | Description
  --- | ---
  ZkController.NotLeaderException | Thrown during leader initiated recovery process if current node is not leader
  ZkController.ResourceModifiedInZkException |

## Package org.apache.solr.cloud Description

Classes for dealing with ZooKeeper when operating in SolrCloud mode.

Copyright © 2000-2016 Apache Software Foundation. All Rights Reserved.