org.aredis.cache

Class ShardedAsyncRedisClient

java.lang.Object

org.aredis.cache.AbstractAsyncRedisClient

org.aredis.cache.ShardedAsyncRedisClient

All Implemented Interfaces:

AsyncRedisClient

public class ShardedAsyncRedisClient
extends AbstractAsyncRedisClient

ShardedAsyncRedisClient is an implementation of AsynRedisClient which holds 2 or more AsyncRedisConnection Objects and forwards the commands to one of them based on the hash of the key in the command. If there are multiple keys all the keys should map to the same server unless aredis supports splitting of the command into multiple commands and aggregating the results of those commands. MGET, MSET and DEL are the commands with multiple keys for which splitting of the command is supported. If multiple keys map to multiple servers and the command is not one of these then an IllegalArgumentException is thrown.

Author:

Suresh

Constructor Summary

Constructors

Constructor and Description
ShardedAsyncRedisClient(List<AsyncRedisConnection> pconnections) Basic Constructor.
ShardedAsyncRedisClient(List<AsyncRedisConnection> pconnections, Executor pexecutor) Constructor which uses ConsistentKeyHasher as default.
ShardedAsyncRedisClient(List<AsyncRedisConnection> pconnections, Executor pexecutor, KeyHasher pkeyHasher) It is preferable to use AsyncRedisFactory than this constructor.

Method Summary

Methods

Modifier and Type	Method and Description
List<AsyncRedisConnection>	getConnections() Gets List of connections
KeyHasher	getKeyHasher() Gets the Keyhasher being used
static int	getUseableConnections(AsyncRedisConnection[] connections, boolean[] useable) Untility Method for use by KeyHashers to return the useable connections.
void	setKeyHasher(KeyHasher pkeyHasher) Sets the Keyhasher
Future<RedisCommandInfo>	submitCommand(RedisCommandInfo commandInfo, AsyncHandler<RedisCommandInfo> completionHandler, boolean requireFutureResult, boolean isSyncCallback) Submit a Redis Command.
Future<RedisCommandInfo[]>	submitCommands(RedisCommandInfo[] commandInfos, AsyncHandler<RedisCommandInfo[]> completionHandler, boolean requireFutureResult, boolean isSyncCallback) Submit multiple Redis Commands.

Methods inherited from class org.aredis.cache.AbstractAsyncRedisClient

sendCommand, sendCommand, sendCommand, sendCommand, submitCommand, submitCommand, submitCommand, submitCommand, submitCommand, submitCommand, submitCommand, submitCommand, submitCommand, submitCommand, submitCommands, submitCommands

Methods inherited from class java.lang.Object

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

Constructor Detail

ShardedAsyncRedisClient

public ShardedAsyncRedisClient(List<AsyncRedisConnection> pconnections,
                       Executor pexecutor,
                       KeyHasher pkeyHasher)

It is preferable to use AsyncRedisFactory than this constructor.

Parameters:

pconnections - Underlying AsyncRedisConnections

pexecutor - Task Executor to use for Asyc APIs. Can be null if you do not use Async APIs with completion handler

pkeyHasher - KeyHasher to use. ConsistentKeyHasher is used as default if null is passed.

ShardedAsyncRedisClient

public ShardedAsyncRedisClient(List<AsyncRedisConnection> pconnections,
                       Executor pexecutor)

Constructor which uses ConsistentKeyHasher as default.

Parameters:

pconnections - Underlying AsyncRedisConnections

pexecutor - Task Executor to use for Asyc APIs. Can be null if you do not use Async APIs with completion handler

ShardedAsyncRedisClient

public ShardedAsyncRedisClient(List<AsyncRedisConnection> pconnections)

Basic Constructor.

Parameters:

pconnections - Underlying AsyncRedisConnections

Method Detail

getUseableConnections

public static int getUseableConnections(AsyncRedisConnection[] connections,
                        boolean[] useable)

Untility Method for use by KeyHashers to return the useable connections.

Parameters:

connections - Array of connections

useable - A boolean array of same size containing true for those connections which are useable

Returns:

A status value to quickly identify the contents of useable array. A return value of -connections.length indicates that all connections are useable which is the ideal thing. A value >= 0 indicates that only 1 connection whose index is the value returned is useable. Any other negative value is -(num flags). num flags will not be 0 because if all flags are false all flags are set to true so that the command is sent anyway.

submitCommands

public Future<RedisCommandInfo[]> submitCommands(RedisCommandInfo[] commandInfos,
                                        AsyncHandler<RedisCommandInfo[]> completionHandler,
                                        boolean requireFutureResult,
                                        boolean isSyncCallback)

Description copied from interface: AsyncRedisClient

Submit multiple Redis Commands.

Specified by:

submitCommands in interface AsyncRedisClient

Specified by:

submitCommands in class AbstractAsyncRedisClient

Parameters:

commandInfos - commands to run along with their parameters

completionHandler - Handler to call upon command completion. Can be null

requireFutureResult - Whether a Future return value is required

isSyncCallback - If true the callback is made directly by the Socket Channel Thread and not the configured executor. Pass true only if the handler logic is extremely light like moving the command to another Q.

Returns:

a Future Object to retrieve the submitted commands containing the results or null if requireFutureResult is passed as false

submitCommand

public Future<RedisCommandInfo> submitCommand(RedisCommandInfo commandInfo,
                                     AsyncHandler<RedisCommandInfo> completionHandler,
                                     boolean requireFutureResult,
                                     boolean isSyncCallback)

Description copied from interface: AsyncRedisClient

Submit a Redis Command.

Specified by:

submitCommand in interface AsyncRedisClient

Specified by:

submitCommand in class AbstractAsyncRedisClient

Parameters:

commandInfo - command to run along with its parameters

completionHandler - Handler to call upon command completion. Can be null

requireFutureResult - Whether a Future return value is required

isSyncCallback - If true the callback is made directly by the Socket Channel Thread and not the configured executor. Pass true only if the handler logic is extremely light like moving the command to another Q.

Returns:

a Future Object to retrieve the submitted command containing the result or null if requireFutureResult is passed as false

getConnections

public List<AsyncRedisConnection> getConnections()

Gets List of connections

Returns:

A List containing the underlying connections

getKeyHasher

public KeyHasher getKeyHasher()

Gets the Keyhasher being used

Returns:

KeyHasher used for distributing a key amongst connections

setKeyHasher

public void setKeyHasher(KeyHasher pkeyHasher)

Sets the Keyhasher

Parameters:

pkeyHasher - KeyHasher to use for distributing a key amongst connections