• Apache Async Http Client Connection Pool

• • Field Summary

    Fields

    Modifier and Type	Field and Description
    protected org.apache.hadoop.yarn.client.api.async.NMClientAsync.CallbackHandler	callbackHandler
    protected NMClient	client

  • Constructor Summary

    Constructors

    Modifier	Constructor and Description
    protected	NMClientAsync(org.apache.hadoop.yarn.client.api.async.NMClientAsync.AbstractCallbackHandler callbackHandler)
    protected	NMClientAsync(org.apache.hadoop.yarn.client.api.async.NMClientAsync.CallbackHandler callbackHandler) Deprecated. Use NMClientAsync(AbstractCallbackHandler) instead.
    protected	NMClientAsync(String name, org.apache.hadoop.yarn.client.api.async.NMClientAsync.AbstractCallbackHandler callbackHandler)
    protected	NMClientAsync(String name, org.apache.hadoop.yarn.client.api.async.NMClientAsync.CallbackHandler callbackHandler) Deprecated. Use NMClientAsync(String, AbstractCallbackHandler) instead.
    protected	NMClientAsync(String name, NMClient client, org.apache.hadoop.yarn.client.api.async.NMClientAsync.AbstractCallbackHandler callbackHandler)
    protected	NMClientAsync(String name, NMClient client, org.apache.hadoop.yarn.client.api.async.NMClientAsync.CallbackHandler callbackHandler)

  • Method Summary

    All MethodsStatic MethodsInstance MethodsAbstract MethodsConcrete MethodsDeprecated Methods

    Modifier and Type	Method and Description
    abstract void	commitLastReInitializationAsync(ContainerId containerId) Commit last reInitialization of the specified container.
    static NMClientAsync	createNMClientAsync(org.apache.hadoop.yarn.client.api.async.NMClientAsync.AbstractCallbackHandler callbackHandler)
    static NMClientAsync	createNMClientAsync(org.apache.hadoop.yarn.client.api.async.NMClientAsync.CallbackHandler callbackHandler) Deprecated. Use createNMClientAsync(AbstractCallbackHandler) instead.
    org.apache.hadoop.yarn.client.api.async.NMClientAsync.CallbackHandler	getCallbackHandler()
    NMClient	getClient()
    abstract void	getContainerStatusAsync(ContainerId containerId, NodeId nodeId)
    abstract void	increaseContainerResourceAsync(Container container)
    abstract void	reInitializeContainerAsync(ContainerId containerId, ContainerLaunchContext containerLaunchContex, boolean autoCommit) Re-Initialize the Container.
    abstract void	restartContainerAsync(ContainerId containerId)
    abstract void	rollbackLastReInitializationAsync(ContainerId containerId) Rollback last reInitialization of the specified container.
    void	setCallbackHandler(org.apache.hadoop.yarn.client.api.async.NMClientAsync.CallbackHandler callbackHandler)
    void	setClient(NMClient client)
    abstract void	startContainerAsync(Container container, ContainerLaunchContext containerLaunchContext)
    abstract void	stopContainerAsync(ContainerId containerId, NodeId nodeId)
    abstract void	updateContainerResourceAsync(Container container)

    • Methods inherited from class org.apache.hadoop.service.AbstractService

      close, getBlockers, getConfig, getFailureCause, getFailureState, getLifecycleHistory, getName, getServiceState, getStartTime, init, isInState, noteFailure, putBlocker, registerGlobalListener, registerServiceListener, removeBlocker, serviceInit, serviceStart, serviceStop, setConfig, start, stop, toString, unregisterGlobalListener, unregisterServiceListener, waitForServiceToStop

    • Methods inherited from class java.lang.Object

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

1. Async Http Client (AHC) Component. Available as of Camel 2.8. The ahc: component provides HTTP based endpoints for consuming external HTTP resources (as a client to call external servers using HTTP). The component uses the Async Http Client library. Maven users will need to add the following dependency to their pom.xml for this component.
2. Apache HTTP Client is a very mature project with plenty of build-in functionality and hooks to customize it. It even has an async module and the newer 5.0 (beta) version comes with build-in async functionality. In our case, after this long explanation to my colleague, given our use cases, moving to Asynchronous HTTP Client was my suggestion.

Apache Async Http Client Connection Pool

Below is the method thats cauing the exception. Public Optional execute (HttpUriRequest request, CloseableHttpAsyncClient closeableHttpAsyncClient, long timeout) HttpResponse response = null; try final Future future = closeableHttpAsyncClient.execute (request, null); // Throwing IllegalStateException: Request cannot.