io.atomix.resource

Interface Resource<T extends Resource<T>>

Type Parameters:

T - resource type

All Superinterfaces:

Managed<T>

All Known Implementing Classes:

AbstractResource

public interface Resource<T extends Resource<T>>
extends Managed<T>

Base class for fault-tolerant stateful distributed objects.

Resources are stateful distributed objects that run across a set of CopycatServers in a cluster.

Resources can be created either as standalone StateMachines in a typical Copycat cluster or as Atomix resources. Operations on the resource are translated into Commands and Querys which are submitted to the cluster where they're logged and replicated.

Resource implementations must be annotated with the ResourceTypeInfo annotation to indicate the ResourceStateMachine to be used by the Atomix resource manager. Additionally, resources must be registered via the ServiceLoader pattern in a file at META-INF/services/io.atomix.resource.Resource on the class path. The resource registration allows the Atomix resource manager to locate and load the resource state machine on each server in the cluster.

Author:

Jordan Halterman

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	Resource.Config Base class for cluster-wide resource configurations.
static class	Resource.Options Base class for local resource options.
static class	Resource.State Resource session state constants.

Method Summary

Modifier and Type	Method and Description
CompletableFuture<Void>	close() Closes the resource.
Resource.Config	config() Returns the resource configuration.
ThreadContext	context() Returns the resource thread context.
CompletableFuture<Void>	delete() Deletes the resource state.
Listener<Resource.State>	onStateChange(Consumer<Resource.State> callback) Registers a resource state change listener.
CompletableFuture<T>	open() Opens the resource.
Resource.Options	options() Returns the resource options.
Serializer	serializer() Returns the resource serializer.
Resource.State	state() Returns the current resource state.
ResourceType	type() Returns the resource type.

Methods inherited from interface io.atomix.catalyst.util.Managed

isClosed, isOpen

Method Detail

type

ResourceType type()

Returns the resource type.

Returns:

The resource type.

serializer

Serializer serializer()

Returns the resource serializer.

Returns:

The resource serializer.

config

Resource.Config config()

Returns the resource configuration.

Returns:

The resource configuration.

options

Resource.Options options()

Returns the resource options.

Returns:

The configured resource options.

state

Resource.State state()

Returns the current resource state.

The resource's Resource.State is indicative of the resource's ability to communicate with the cluster at any given time. Users of the resource should use the state to determine when guarantees may be lost. See the Resource.State documentation for information on the specific states, and see resource implementation documentation for the implications of different states on resource consistency.

Returns:

The current resource state.

onStateChange

Listener<Resource.State> onStateChange(Consumer<Resource.State> callback)

Registers a resource state change listener.

Parameters:

callback - The callback to call when the resource state changes.

Returns:

The state change listener.

context

ThreadContext context()

Returns the resource thread context.

Returns:

The resource thread context.

open

CompletableFuture<T> open()

Opens the resource.

Once the resource is opened, the resource will be transitioned to the Resource.State.CONNECTED state and the returned CompletableFuture will be completed.

Specified by:

open in interface Managed<T extends Resource<T>>

Returns:

A completable future to be completed once the resource is opened.

close

CompletableFuture<Void> close()

Closes the resource.

Once the resource is closed, the resource will be transitioned to the Resource.State.CLOSED state and the returned CompletableFuture will be completed. Thereafter, attempts to operate on the resource will fail.

Specified by:

close in interface Managed<T extends Resource<T>>

Returns:

A completable future to be completed once the resource is closed.

delete

CompletableFuture<Void> delete()

Deletes the resource state.

Returns:

A completable future to be completed once the resource has been deleted.