services.moleculer.strategy

Class ShardStrategyFactory

java.lang.Object

services.moleculer.service.MoleculerComponent

services.moleculer.strategy.StrategyFactory

services.moleculer.strategy.ArrayBasedStrategyFactory

services.moleculer.strategy.ShardStrategyFactory

All Implemented Interfaces:

MoleculerLifecycle

public class ShardStrategyFactory
extends ArrayBasedStrategyFactory

Sharding invocation strategy factory. Using consistent-hashing.
More info: https://www.toptal.com/big-data/consistent-hashing

See Also:

RoundRobinStrategyFactory, SecureRandomStrategyFactory, XorShiftRandomStrategyFactory, NanoSecRandomStrategyFactory, CpuUsageStrategyFactory, NetworkLatencyStrategyFactory

Field Summary

Fields

Modifier and Type	Field and Description
protected int	cacheSize Size of the memory cache (0 = disabled)
protected java.util.function.Function<java.lang.String,java.lang.Long>	hash Default hash function (MD5).
protected java.lang.Integer	ringSize Ring size (optional)
protected java.lang.String	shardKey Shard key's path (eg.
protected int	vnodes Number of virtual nodes

Fields inherited from class services.moleculer.strategy.ArrayBasedStrategyFactory

preferLocal

Fields inherited from class services.moleculer.service.MoleculerComponent

broker, logger, name

Constructor Summary

Constructors

Constructor and Description
ShardStrategyFactory() Constructor that calls for service based primarily on its own (hash-based) logic.
ShardStrategyFactory(boolean preferLocal) Constructor that can be configured to use local services if possible.
ShardStrategyFactory(boolean preferLocal, java.lang.String shardKey) Constructor that can be configured to use local services if possible.
ShardStrategyFactory(java.lang.String shardKey) Constructor that can be configured to use local services if possible.

Method Summary

Modifier and Type	Method and Description
<T extends Endpoint> Strategy<T>	create()
int	getCacheSize()
java.util.function.Function<java.lang.String,java.lang.Long>	getHash()
java.lang.Integer	getRingSize()
java.lang.String	getShardKey()
int	getVnodes()
void	setCacheSize(int cacheSize)
void	setHash(java.util.function.Function<java.lang.String,java.lang.Long> hash)
void	setRingSize(java.lang.Integer ringSize)
void	setShardKey(java.lang.String shardKey)
void	setVnodes(int vnodes)

Methods inherited from class services.moleculer.strategy.ArrayBasedStrategyFactory

isPreferLocal, setPreferLocal

Methods inherited from class services.moleculer.service.MoleculerComponent

getBroker, getLogger, getName, started, stopped

Methods inherited from class java.lang.Object

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

Field Detail

shardKey

protected java.lang.String shardKey

Shard key's path (eg. "userID", "user.email", "#key", etc.)

vnodes

protected int vnodes

Number of virtual nodes

ringSize

protected java.lang.Integer ringSize

Ring size (optional)

cacheSize

protected int cacheSize

Size of the memory cache (0 = disabled)

hash

protected java.util.function.Function<java.lang.String,java.lang.Long> hash

Default hash function (MD5).

Constructor Detail

ShardStrategyFactory

public ShardStrategyFactory()

Constructor that calls for service based primarily on its own (hash-based) logic. Does not matter if the service is available locally.

ShardStrategyFactory

public ShardStrategyFactory(boolean preferLocal)

Constructor that can be configured to use local services if possible.

Parameters:

preferLocal - invoke local actions if possible

ShardStrategyFactory

public ShardStrategyFactory(java.lang.String shardKey)

Constructor that can be configured to use local services if possible.

Parameters:

shardKey - Shard key's path (eg. "userID", "user.email", "#key", etc.)

ShardStrategyFactory

public ShardStrategyFactory(boolean preferLocal,
                            java.lang.String shardKey)

Constructor that can be configured to use local services if possible.

Parameters:

preferLocal - invoke local actions if possible

shardKey - Shard key's path (eg. "userID", "user.email", "#key", etc.)

Method Detail

create

public <T extends Endpoint> Strategy<T> create()

Specified by:

create in class StrategyFactory

getShardKey

public java.lang.String getShardKey()

setShardKey

public void setShardKey(java.lang.String shardKey)

getVnodes

public int getVnodes()

setVnodes

public void setVnodes(int vnodes)

getRingSize

public java.lang.Integer getRingSize()

setRingSize

public void setRingSize(java.lang.Integer ringSize)

getCacheSize

public int getCacheSize()

setCacheSize

public void setCacheSize(int cacheSize)

getHash

public java.util.function.Function<java.lang.String,java.lang.Long> getHash()

setHash

public void setHash(java.util.function.Function<java.lang.String,java.lang.Long> hash)