com.hazelcast.scheduledexecutor

Interface IScheduledExecutorService

All Superinterfaces:

DistributedObject

public interface IScheduledExecutorService
extends DistributedObject

Distributed & durable implementation similar to, but not directly inherited ScheduledExecutorService. IScheduledExecutorService provides similar API to the ScheduledExecutorService with some exceptions but also additional methods like scheduling tasks on a specific member, on a member who is owner of a specific key, executing a tasks on multiple members etc.

Tasks (Runnable and/or Callable) scheduled on any partition through an IScheduledExecutorService, yield some durability characteristics.

• When a node goes down (up to durability config), the scheduled task will get re-scheduled on a replica node.
• In the event of a partition migration, the task will be re-scheduled on the destination node.

Note: The above characteristics don't apply when scheduled on a Member.

Upon scheduling, a task acquires a resource handler, see ScheduledTaskHandler. The handler is generated before the actual scheduling of the task on the node, which allows for a way to access the future in an event of a node failure, immediately after scheduling, and also guarantees no duplicates in the cluster by utilising a unique name per task. A name can also be defined by the user by having the Runnable or Callable implement the NamedTask. Alternatively, one can wrap any task using the TaskUtils.named(String, Callable) or TaskUtils.named(String, Runnable) for simplicity.

One difference of this service in comparison to ScheduledExecutorService is the scheduleAtFixedRate(Runnable, long, long, TimeUnit) which has similar semantic to ScheduledExecutorService.scheduleAtFixedRate(Runnable, long, long, TimeUnit). It guarantees a task won't be executed by multiple threads concurrently. The difference is that this service will skip a scheduled execution if another thread is still running the same task, instead of postponing its execution.

The other difference is this service does not offer an equivalent of ScheduledExecutorService.scheduleWithFixedDelay(Runnable, long, long, TimeUnit)

Tasks that are holding state that needs to be also durable across partitions, will need to implement the StatefulTask interface.

Supports split brain protection SplitBrainProtectionConfig since 3.10 in cluster versions 3.10 and higher.

Method Summary

Modifier and Type	Method and Description
<V> Map<Member,List<IScheduledFuture<V>>>	getAllScheduledFutures() Fetches and returns all scheduled (not disposed yet) futures from all members in the cluster.
<V> IScheduledFuture<V>	getScheduledFuture(ScheduledTaskHandler handler) Creates a new IScheduledFuture from the given handler.
<V> IScheduledFuture<V>	schedule(Callable<V> command, long delay, TimeUnit unit) Creates and executes a one-shot action that becomes enabled after the given delay.
<V> IScheduledFuture<V>	schedule(Runnable command, long delay, TimeUnit unit) Creates and executes a one-shot action that becomes enabled after the given delay.
<V> IScheduledFuture<V>	scheduleAtFixedRate(Runnable command, long initialDelay, long period, TimeUnit unit) Creates and executes a periodic action that becomes enabled first after the given initial delay, and subsequently with the given period.
<V> Map<Member,IScheduledFuture<V>>	scheduleOnAllMembers(Callable<V> command, long delay, TimeUnit unit) Creates and executes a one-shot action that becomes enabled after the given delay on all cluster Members.
<V> Map<Member,IScheduledFuture<V>>	scheduleOnAllMembers(Runnable command, long delay, TimeUnit unit) Creates and executes a one-shot action that becomes enabled after the given delay on all cluster Members.
<V> Map<Member,IScheduledFuture<V>>	scheduleOnAllMembersAtFixedRate(Runnable command, long initialDelay, long period, TimeUnit unit) Creates and executes a periodic action that becomes enabled first after the given initial delay, and subsequently with the given period on all cluster Members.
<V> IScheduledFuture<V>	scheduleOnKeyOwner(Callable<V> command, Object key, long delay, TimeUnit unit) Creates and executes a one-shot action that becomes enabled after the given delay on the partition owner of the given key.
<V> IScheduledFuture<V>	scheduleOnKeyOwner(Runnable command, Object key, long delay, TimeUnit unit) Creates and executes a one-shot action that becomes enabled after the given delay on the partition owner of the given key.
<V> IScheduledFuture<V>	scheduleOnKeyOwnerAtFixedRate(Runnable command, Object key, long initialDelay, long period, TimeUnit unit) Creates and executes a periodic action that becomes enabled first after the given initial delay, and subsequently with the given period on the partition owner of the given key.
<V> IScheduledFuture<V>	scheduleOnMember(Callable<V> command, Member member, long delay, TimeUnit unit) Creates and executes a one-shot action that becomes enabled after the given delay at the given Member.
<V> IScheduledFuture<V>	scheduleOnMember(Runnable command, Member member, long delay, TimeUnit unit) Creates and executes a one-shot action that becomes enabled after the given delay at the given Member.
<V> IScheduledFuture<V>	scheduleOnMemberAtFixedRate(Runnable command, Member member, long initialDelay, long period, TimeUnit unit) Creates and executes a periodic action that becomes enabled first after the given initial delay, and subsequently with the given period at the given Member.
<V> Map<Member,IScheduledFuture<V>>	scheduleOnMembers(Callable<V> command, Collection<Member> members, long delay, TimeUnit unit) Creates and executes a one-shot action that becomes enabled after the given delay on all Members given.
<V> Map<Member,IScheduledFuture<V>>	scheduleOnMembers(Runnable command, Collection<Member> members, long delay, TimeUnit unit) Creates and executes a one-shot action that becomes enabled after the given delay on all Members given.
<V> Map<Member,IScheduledFuture<V>>	scheduleOnMembersAtFixedRate(Runnable command, Collection<Member> members, long initialDelay, long period, TimeUnit unit) Creates and executes a periodic action that becomes enabled first after the given initial delay, and subsequently with the given period on all Members given.
void	shutdown() Initiates an orderly shutdown in which previously submitted tasks are executed, but no new tasks will be accepted.

Methods inherited from interface com.hazelcast.core.DistributedObject

destroy, getName, getPartitionKey, getServiceName

Method Detail

schedule

@Nonnull
<V> IScheduledFuture<V> schedule(@Nonnull
                                          Runnable command,
                                          long delay,
                                          @Nonnull
                                          TimeUnit unit)

Creates and executes a one-shot action that becomes enabled after the given delay.

Type Parameters:

V - the result type of the returned ScheduledFuture

Parameters:

command - the task to execute

delay - the time from now to delay execution

unit - the time unit of the delay parameter

Returns:

a ScheduledFuture representing pending completion of the task and whose get() method will return null upon completion

Throws:

RejectedExecutionException - if the task cannot be scheduled for execution

NullPointerException - if command is null

schedule

@Nonnull
<V> IScheduledFuture<V> schedule(@Nonnull
                                          Callable<V> command,
                                          long delay,
                                          @Nonnull
                                          TimeUnit unit)

Creates and executes a one-shot action that becomes enabled after the given delay.

Type Parameters:

V - the return type of callable tasks

Parameters:

command - the task to execute

delay - the time from now to delay execution

unit - the time unit of the delay parameter

Returns:

a ScheduledFuture representing pending completion of the task and whose get() method will return null upon completion

Throws:

RejectedExecutionException - if the task cannot be scheduled for execution

NullPointerException - if command is null

scheduleAtFixedRate

@Nonnull
<V> IScheduledFuture<V> scheduleAtFixedRate(@Nonnull
                                                     Runnable command,
                                                     long initialDelay,
                                                     long period,
                                                     @Nonnull
                                                     TimeUnit unit)

Creates and executes a periodic action that becomes enabled first after the given initial delay, and subsequently with the given period. Executions will commence after initialDelay then initialDelay+period, then initialDelay + 2 * period, and so on. If any execution of this task takes longer than its period, then subsequent execution will be skipped. If any execution of the task encounters an exception, subsequent executions are suppressed. Otherwise, the task will only terminate via cancellation or termination of the executor.

Type Parameters:

V - the result type of the returned ScheduledFuture

Parameters:

command - the task to execute

initialDelay - the time to delay first execution

period - the period between successive executions

unit - the time unit of the initialDelay and period parameters

Returns:

a ScheduledFuture representing pending completion of the task, and whose get() method will throw an exception upon cancellation

Throws:

RejectedExecutionException - if the task cannot be scheduled for execution

NullPointerException - if command is null

scheduleOnMember

@Nonnull
<V> IScheduledFuture<V> scheduleOnMember(@Nonnull
                                                  Runnable command,
                                                  @Nonnull
                                                  Member member,
                                                  long delay,
                                                  @Nonnull
                                                  TimeUnit unit)

Creates and executes a one-shot action that becomes enabled after the given delay at the given Member.

Type Parameters:

V - the result type of the returned ScheduledFuture

Parameters:

command - the task to execute

member - the member to execute the task

delay - the time from now to delay execution

unit - the time unit of the delay parameter

Returns:

a ScheduledFuture representing pending completion of the task and whose get() method will return null upon completion

Throws:

RejectedExecutionException - if the task cannot be scheduled for execution

NullPointerException - if command is null

scheduleOnMember

@Nonnull
<V> IScheduledFuture<V> scheduleOnMember(@Nonnull
                                                  Callable<V> command,
                                                  @Nonnull
                                                  Member member,
                                                  long delay,
                                                  @Nonnull
                                                  TimeUnit unit)

Creates and executes a one-shot action that becomes enabled after the given delay at the given Member.

Type Parameters:

V - the return type of callable tasks

Parameters:

command - the task to execute

member - the member to execute the task

delay - the time from now to delay execution

unit - the time unit of the delay parameter

Returns:

a ScheduledFuture representing pending completion of the task and whose get() method will return null upon completion

Throws:

RejectedExecutionException - if the task cannot be scheduled for execution

NullPointerException - if command is null

scheduleOnMemberAtFixedRate

@Nonnull
<V> IScheduledFuture<V> scheduleOnMemberAtFixedRate(@Nonnull
                                                             Runnable command,
                                                             @Nonnull
                                                             Member member,
                                                             long initialDelay,
                                                             long period,
                                                             @Nonnull
                                                             TimeUnit unit)

Creates and executes a periodic action that becomes enabled first after the given initial delay, and subsequently with the given period at the given Member. Executions will commence after initialDelay then initialDelay+period, then initialDelay + 2 * period, and so on. If any execution of this task takes longer than its period, then subsequent execution will be skipped. If any execution of the task encounters an exception, subsequent executions are suppressed. Otherwise, the task will only terminate via cancellation or termination of the executor.

Type Parameters:

V - the result type of the returned ScheduledFuture

Parameters:

command - the task to execute

member - the member to execute the task

initialDelay - the time to delay first execution

period - the period between successive executions

unit - the time unit of the initialDelay and period parameters

Returns:

a ScheduledFuture representing pending completion of the task, and whose get() method will throw an exception upon cancellation

Throws:

RejectedExecutionException - if the task cannot be scheduled for execution

NullPointerException - if command is null

scheduleOnKeyOwner

@Nonnull
<V> IScheduledFuture<V> scheduleOnKeyOwner(@Nonnull
                                                    Runnable command,
                                                    @Nonnull
                                                    Object key,
                                                    long delay,
                                                    @Nonnull
                                                    TimeUnit unit)

Creates and executes a one-shot action that becomes enabled after the given delay on the partition owner of the given key.

Type Parameters:

V - the result type of the returned ScheduledFuture

Parameters:

command - the task to execute

key - the key to identify the partition owner, which will execute the task

delay - the time from now to delay execution

unit - the time unit of the delay parameter

Returns:

a ScheduledFuture representing pending completion of the task and whose get() method will return null upon completion

Throws:

RejectedExecutionException - if the task cannot be scheduled for execution

NullPointerException - if command is null

scheduleOnKeyOwner

@Nonnull
<V> IScheduledFuture<V> scheduleOnKeyOwner(@Nonnull
                                                    Callable<V> command,
                                                    @Nonnull
                                                    Object key,
                                                    long delay,
                                                    @Nonnull
                                                    TimeUnit unit)

Creates and executes a one-shot action that becomes enabled after the given delay on the partition owner of the given key.

Type Parameters:

V - the return type of callable tasks

Parameters:

command - the task to execute

key - the key to identify the partition owner, which will execute the task

delay - the time from now to delay execution

unit - the time unit of the delay parameter

Returns:

a ScheduledFuture representing pending completion of the task and whose get() method will return null upon completion

Throws:

RejectedExecutionException - if the task cannot be scheduled for execution

NullPointerException - if command is null

scheduleOnKeyOwnerAtFixedRate

@Nonnull
<V> IScheduledFuture<V> scheduleOnKeyOwnerAtFixedRate(@Nonnull
                                                               Runnable command,
                                                               @Nonnull
                                                               Object key,
                                                               long initialDelay,
                                                               long period,
                                                               @Nonnull
                                                               TimeUnit unit)

Creates and executes a periodic action that becomes enabled first after the given initial delay, and subsequently with the given period on the partition owner of the given key. Executions will commence after initialDelay then initialDelay+period, then initialDelay + 2 * period, and so on. If any execution of this task takes longer than its period, then subsequent execution will be skipped. If any execution of the task encounters an exception, subsequent executions are suppressed. Otherwise, the task will only terminate via cancellation or termination of the executor.

Type Parameters:

V - the result type of the returned ScheduledFuture

Parameters:

command - the task to execute

key - the key to identify the partition owner, which will execute the task

initialDelay - the time to delay first execution

period - the period between successive executions

unit - the time unit of the initialDelay and period parameters

Returns:

a ScheduledFuture representing pending completion of the task, and whose get() method will throw an exception upon cancellation

Throws:

RejectedExecutionException - if the task cannot be scheduled for execution

NullPointerException - if command is null

scheduleOnAllMembers

@Nonnull
<V> Map<Member,IScheduledFuture<V>> scheduleOnAllMembers(@Nonnull
                                                                  Runnable command,
                                                                  long delay,
                                                                  @Nonnull
                                                                  TimeUnit unit)

Creates and executes a one-shot action that becomes enabled after the given delay on all cluster Members.

Note: In the event of Member leaving the cluster, for whatever reason, the task is lost. If a new member is added, the task will not get scheduled there automatically.

Type Parameters:

V - the result type of the returned ScheduledFuture

Parameters:

command - the task to execute

delay - the time from now to delay execution

unit - the time unit of the delay parameter

Returns:

a ScheduledFuture representing pending completion of the task and whose get() method will return null upon completion

Throws:

RejectedExecutionException - if the task cannot be scheduled for execution

NullPointerException - if command is null

scheduleOnAllMembers

@Nonnull
<V> Map<Member,IScheduledFuture<V>> scheduleOnAllMembers(@Nonnull
                                                                  Callable<V> command,
                                                                  long delay,
                                                                  @Nonnull
                                                                  TimeUnit unit)

Creates and executes a one-shot action that becomes enabled after the given delay on all cluster Members.

Note: In the event of Member leaving the cluster, for whatever reason, the task is lost. If a new member is added, the task will not get scheduled there automatically.

Type Parameters:

V - the return type of callable tasks

Parameters:

command - the task to execute

delay - the time from now to delay execution

unit - the time unit of the delay parameter

Returns:

a ScheduledFuture representing pending completion of the task and whose get() method will return null upon completion

Throws:

RejectedExecutionException - if the task cannot be scheduled for execution

NullPointerException - if command is null

scheduleOnAllMembersAtFixedRate

@Nonnull
<V> Map<Member,IScheduledFuture<V>> scheduleOnAllMembersAtFixedRate(@Nonnull
                                                                             Runnable command,
                                                                             long initialDelay,
                                                                             long period,
                                                                             @Nonnull
                                                                             TimeUnit unit)

Creates and executes a periodic action that becomes enabled first after the given initial delay, and subsequently with the given period on all cluster Members. Executions will commence after initialDelay then initialDelay+period, then initialDelay + 2 * period, and so on. If any execution of this task takes longer than its period, then subsequent execution will be skipped. If any execution of the task encounters an exception, subsequent executions are suppressed. Otherwise, the task will only terminate via cancellation or termination of the executor.

Note: In the event of Member leaving the cluster, for whatever reason, the task is lost. If a new member is added, the task will not get scheduled there automatically.

Type Parameters:

V - the result type of the returned ScheduledFuture

Parameters:

command - the task to execute

initialDelay - the time to delay first execution

period - the period between successive executions

unit - the time unit of the initialDelay and period parameters

Returns:

a ScheduledFuture representing pending completion of the task, and whose get() method will throw an exception upon cancellation

Throws:

RejectedExecutionException - if the task cannot be scheduled for execution

NullPointerException - if command is null

scheduleOnMembers

@Nonnull
<V> Map<Member,IScheduledFuture<V>> scheduleOnMembers(@Nonnull
                                                               Runnable command,
                                                               @Nonnull
                                                               Collection<Member> members,
                                                               long delay,
                                                               @Nonnull
                                                               TimeUnit unit)

Creates and executes a one-shot action that becomes enabled after the given delay on all Members given.

Note: In the event of Member leaving the cluster, for whatever reason, the task is lost.

Type Parameters:

V - the result type of the returned ScheduledFuture

Parameters:

command - the task to execute

members - the collections of members - where to execute the task

delay - the time from now to delay execution

unit - the time unit of the delay parameter

Returns:

a ScheduledFuture representing pending completion of the task and whose get() method will return null upon completion

Throws:

RejectedExecutionException - if the task cannot be scheduled for execution

NullPointerException - if command is null

scheduleOnMembers

@Nonnull
<V> Map<Member,IScheduledFuture<V>> scheduleOnMembers(@Nonnull
                                                               Callable<V> command,
                                                               @Nonnull
                                                               Collection<Member> members,
                                                               long delay,
                                                               @Nonnull
                                                               TimeUnit unit)

Creates and executes a one-shot action that becomes enabled after the given delay on all Members given.

Note: In the event of Member leaving the cluster, for whatever reason, the task is lost.

Type Parameters:

V - the return type of callable tasks

Parameters:

command - the task to execute

members - the collections of members - where to execute the task

delay - the time from now to delay execution

unit - the time unit of the delay parameter

Returns:

a ScheduledFuture representing pending completion of the task and whose get() method will return null upon completion

Throws:

RejectedExecutionException - if the task cannot be scheduled for execution

NullPointerException - if command is null

scheduleOnMembersAtFixedRate

@Nonnull
<V> Map<Member,IScheduledFuture<V>> scheduleOnMembersAtFixedRate(@Nonnull
                                                                          Runnable command,
                                                                          @Nonnull
                                                                          Collection<Member> members,
                                                                          long initialDelay,
                                                                          long period,
                                                                          @Nonnull
                                                                          TimeUnit unit)

Creates and executes a periodic action that becomes enabled first after the given initial delay, and subsequently with the given period on all Members given. Executions will commence after initialDelay then initialDelay+period, then initialDelay + 2 * period, and so on. If any execution of this task takes longer than its period, then subsequent execution will be skipped. If any execution of the task encounters an exception, subsequent executions are suppressed. Otherwise, the task will only terminate via cancellation or termination of the executor.

Note: In the event of Member leaving the cluster, for whatever reason, the task is lost.

Type Parameters:

V - the result type of the returned ScheduledFuture

Parameters:

command - the task to execute

members - the collections of members - where to execute the task

initialDelay - the time to delay first execution

period - the period between successive executions

unit - the time unit of the initialDelay and period parameters

Returns:

a ScheduledFuture representing pending completion of the task, and whose get() method will throw an exception upon cancellation

Throws:

RejectedExecutionException - if the task cannot be scheduled for execution

NullPointerException - if command is null

getScheduledFuture

@Nonnull
<V> IScheduledFuture<V> getScheduledFuture(@Nonnull
                                                    ScheduledTaskHandler handler)

Creates a new IScheduledFuture from the given handler. This is useful in case your member node or client from which the original scheduling happened, went down, and now you want to access the ScheduledFuture again.

Type Parameters:

V - the result type of the returned ScheduledFuture

Parameters:

handler - The handler of the task as found from IScheduledFuture.getHandler()

Returns:

A new IScheduledFuture from the given handler.

getAllScheduledFutures

@Nonnull
<V> Map<Member,List<IScheduledFuture<V>>> getAllScheduledFutures()

Fetches and returns all scheduled (not disposed yet) futures from all members in the cluster. If a member has no running tasks for this scheduler, it wont be included in the returned Map.

Type Parameters:

V - the result type of the returned ScheduledFuture

Returns:

A Map with Member keys and a List of IScheduledFuture found for this scheduler.

shutdown

void shutdown()

Initiates an orderly shutdown in which previously submitted tasks are executed, but no new tasks will be accepted. Invocation has no additional effect if already shut down.

This method does not wait for previously submitted tasks to complete execution.