com.gemstone.gemfire.cache.execute
Class FunctionService

java.lang.Object
  com.gemstone.gemfire.cache.execute.FunctionService

public final class FunctionService
extends Object

Provides the entry point into execution of user defined Functions.

Function execution provides a mean to route application behaviour to data or more generically to peers in a DistributedSystem or servers in a Pool.

Since:

6.0

Method Summary

static Function	getFunction(String functionId) Returns the Function defined by the functionId, returns null if no function is found for the specified functionId
static Map<String,Function>	getRegisteredFunctions() Returns all locally registered functions
static boolean	isRegistered(String functionId) Returns true if the function is registered to FunctionService
static Execution	onMember(DistributedSystem system, DistributedMember distributedMember) Returns an Execution object that can be used to execute a data independent function on a DistributedMember of the DistributedSystem.
static Execution	onMembers(DistributedSystem system) Returns an Execution object that can be used to execute a data independent function on all members of the DistributedSystem.
static Execution	onMembers(DistributedSystem system, Set<DistributedMember> distributedMembers) Returns an Execution object that can be used to execute a data independent function on the set of DistributedMembers of the DistributedSystem.
static Execution	onRegion(Region region) Returns an Execution object that can be used to execute a data dependent function on the specified Region.
static Execution	onServer(Pool pool) Returns an Execution object that can be used to execute a data independent function on a server in the provided Pool.
static Execution	onServers(Pool pool) Returns an Execution object that can be used to execute a data independent function on all the servers in the provided Pool.
static void	registerFunction(Function function) Registers the given Function with the FunctionService using Function.getId().
static void	unregisterFunction(String functionId) Unregisters the given Function with the FunctionService using Function.getId().

Methods inherited from class java.lang.Object

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

Method Detail

onRegion

public static Execution onRegion(Region region)

Returns an Execution object that can be used to execute a data dependent function on the specified Region.
When invoked from a GemFire client, the method returns an Execution instance that sends a message to one of the connected servers as specified by the Pool for the region.
Depending on the filters setup on the Execution, the function is executed on all GemFire members that define the data region, or a subset of members. Execution.withFilter(Set)). For DistributedRegions with DataPolicy.NORMAL, it throws UnsupportedOperationException For DistributedRegions with DataPolicy.EMPTY, execute the function on any random member which has DataPolicy.RELPICATE
For DistributedRegions with DataPolicy.REPLICATE, execute the function locally For Regions with DataPolicy.PARTITION, it executes on members where the data resides as specified by the filter.

Parameters:

region -

Returns:

Execution

Throws:

NullPointerException - if the region passed in is null

Since:

6.0

onServer

public static Execution onServer(Pool pool)

Returns an Execution object that can be used to execute a data independent function on a server in the provided Pool.

If the server goes down while dispatching or executing the function, an Exception will be thrown.

Parameters:

pool - from which to chose a server for execution

Returns:

Execution

Throws:

NullPointerException - if Pool instance passed in is null

Since:

6.0

onServers

public static Execution onServers(Pool pool)

Returns an Execution object that can be used to execute a data independent function on all the servers in the provided Pool. If one of the servers goes down while dispatching or executing the function on the server, an Exception will be thrown.

Parameters:

pool - the set of servers to execute the function

Returns:

Execution

Throws:

NullPointerException - if Pool instance passed in is null

Since:

6.0

onMember

public static Execution onMember(DistributedSystem system,
                                 DistributedMember distributedMember)

Returns an Execution object that can be used to execute a data independent function on a DistributedMember of the DistributedSystem. If the member is not found in the system, the function execution will throw an Exception. If the member goes down while dispatching or executing the function on the member, an Exception will be thrown.

Parameters:

system - defines the distributed system

distributedMember - defines a member in the distributed system

Returns:

Execution

Throws:

NullPointerException - if either input parameter is null

Since:

6.0

onMembers

public static Execution onMembers(DistributedSystem system)

Returns an Execution object that can be used to execute a data independent function on all members of the DistributedSystem. If one of the members goes down while dispatching or executing the function on the member, an Exception will be thrown.

Parameters:

system - defines the distributed system

Returns:

Execution

Throws:

NullPointerException - if DistributedSystem instance passed is null

Since:

6.0

onMembers

public static Execution onMembers(DistributedSystem system,
                                  Set<DistributedMember> distributedMembers)

Returns an Execution object that can be used to execute a data independent function on the set of DistributedMembers of the DistributedSystem. If one of the members goes down while dispatching or executing the function, an Exception will be thrown.

Parameters:

system - defines the distributed system

distributedMembers - set of distributed members on which Function to be executed

Throws:

NullPointerException - if DistributedSystem instance passed is null

Since:

6.0

getFunction

public static Function getFunction(String functionId)

Returns the Function defined by the functionId, returns null if no function is found for the specified functionId

Parameters:

functionId -

Returns:

Function

Since:

6.0

registerFunction

public static void registerFunction(Function function)

Registers the given Function with the FunctionService using Function.getId().

Registering a function allows execution of the function using Execution.execute(String). Every member that could execute a function using its Function.getId() should register the function.

Throws:

NullPointerException - if function instance passed is null or Function.getId() returns null

Since:

6.0

unregisterFunction

public static void unregisterFunction(String functionId)

Unregisters the given Function with the FunctionService using Function.getId().

Throws:

NullPointerException - if function instance passed is null or Function.getId() returns null

Since:

6.0

isRegistered

public static boolean isRegistered(String functionId)

Returns true if the function is registered to FunctionService

Throws:

NullPointerException - if function instance passed is null or Function.getId() returns null

Since:

6.0

getRegisteredFunctions

public static Map<String,Function> getRegisteredFunctions()

Returns all locally registered functions

Returns:

a live read-only view of registered functions as a Map of Function.getId() to Function

Since:

6.0