org.apache.solr.cloud

Class Overseer

java.lang.Object

org.apache.solr.cloud.Overseer

All Implemented Interfaces:

Closeable, AutoCloseable

public class Overseer
extends Object
implements Closeable

Cluster leader. Responsible for processing state updates, node assignments, creating/deleting collections, shards, replicas and setting various properties.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Overseer.FailedOp
static class	Overseer.Stat
static class	Overseer.Stats Used to hold statistics about overseer operations.

Field Summary

Fields

Modifier and Type	Field and Description
static int	NUM_RESPONSES_TO_STORE
static String	QUEUE_OPERATION
static int	STATE_UPDATE_DELAY

Constructor Summary

Constructors

Constructor and Description
Overseer(ShardHandler shardHandler, UpdateShardHandler updateShardHandler, String adminPath, ZkStateReader reader, ZkController zkController, CloudConfig config)

Method Summary

Modifier and Type	Method and Description
void	close()
static DistributedQueue	getStateUpdateQueue(SolrZkClient zkClient) Get queue that can be used to send messages to Overseer.
Overseer.Stats	getStats()
org.apache.solr.cloud.Overseer.OverseerThread	getUpdaterThread() For tests.
ZkStateReader	getZkStateReader()
static boolean	isLegacy(ZkStateReader stateReader)
void	start(String id)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

QUEUE_OPERATION

public static final String QUEUE_OPERATION

See Also:

Constant Field Values

STATE_UPDATE_DELAY

public static final int STATE_UPDATE_DELAY

See Also:

Constant Field Values

NUM_RESPONSES_TO_STORE

public static final int NUM_RESPONSES_TO_STORE

See Also:

Constant Field Values

Constructor Detail

Overseer

public Overseer(ShardHandler shardHandler,
                UpdateShardHandler updateShardHandler,
                String adminPath,
                ZkStateReader reader,
                ZkController zkController,
                CloudConfig config)
         throws org.apache.zookeeper.KeeperException,
                InterruptedException

Throws:

org.apache.zookeeper.KeeperException

InterruptedException

Method Detail

start

public void start(String id)

getStats

public Overseer.Stats getStats()

getUpdaterThread

public org.apache.solr.cloud.Overseer.OverseerThread getUpdaterThread()

For tests.

Returns:

state updater thread

NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.

close

public void close()

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

getStateUpdateQueue

public static DistributedQueue getStateUpdateQueue(SolrZkClient zkClient)

Get queue that can be used to send messages to Overseer.

Any and all modifications to the cluster state must be sent to the overseer via this queue. The complete list of overseer actions supported by this queue are documented inside the OverseerAction enum.

Performance statistics on the returned queue are not tracked by the Overseer Stats API, see CollectionParams.CollectionAction.OVERSEERSTATUS. Therefore, this method should be used only by clients for writing to the overseer queue.

This method will create the /overseer znode in ZooKeeper if it does not exist already.

Parameters:

zkClient - the SolrZkClient to be used for reading/writing to the queue

Returns:

a DistributedQueue object

isLegacy

public static boolean isLegacy(ZkStateReader stateReader)

getZkStateReader

public ZkStateReader getZkStateReader()