Package com.netflix.hystrix.strategy.executionhook

Class HystrixCommandExecutionHook

java.lang.Object

com.netflix.hystrix.strategy.executionhook.HystrixCommandExecutionHook

Direct Known Subclasses:

HystrixCommandExecutionHookDefault

public abstract class HystrixCommandExecutionHook
extends java.lang.Object

Abstract ExecutionHook with invocations at different lifecycle points of HystrixCommand and HystrixObservableCommand execution with default no-op implementations.

See HystrixPlugins or the Hystrix GitHub Wiki for information on configuring plugins: https://github.com/Netflix/Hystrix/wiki/Plugins.

Note on thread-safety and performance

A single implementation of this class will be used globally so methods on this class will be invoked concurrently from multiple threads so all functionality must be thread-safe.

Methods are also invoked synchronously and will add to execution time of the commands so all behavior should be fast. If anything time-consuming is to be done it should be spawned asynchronously onto separate worker threads.

Since:

1.2

Constructor Summary

Constructors

Constructor and Description
HystrixCommandExecutionHook()

Method Summary

Modifier and Type	Method and Description
<T> void	onCacheHit(HystrixInvokable<T> commandInstance) Invoked when the command response is found in the HystrixRequestCache.
<T> T	onComplete(HystrixCommand<T> commandInstance, T response) Deprecated.
<T> T	onComplete(HystrixInvokable<T> commandInstance, T response) Deprecated.
<T> T	onEmit(HystrixInvokable<T> commandInstance, T value) Invoked when HystrixInvokable emits a value.
<T> java.lang.Exception	onError(HystrixCommand<T> commandInstance, HystrixRuntimeException.FailureType failureType, java.lang.Exception e) Deprecated.
<T> java.lang.Exception	onError(HystrixInvokable<T> commandInstance, HystrixRuntimeException.FailureType failureType, java.lang.Exception e) Invoked when HystrixInvokable fails with an Exception.
<T> T	onExecutionEmit(HystrixInvokable<T> commandInstance, T value) Invoked when the user-defined execution method in HystrixInvokable emits a value.
<T> java.lang.Exception	onExecutionError(HystrixInvokable<T> commandInstance, java.lang.Exception e) Invoked when the user-defined execution method in HystrixInvokable fails with an Exception.
<T> void	onExecutionStart(HystrixInvokable<T> commandInstance) Invoked when the user-defined execution method in HystrixInvokable starts.
<T> void	onExecutionSuccess(HystrixInvokable<T> commandInstance) Invoked when the user-defined execution method in HystrixInvokable completes successfully.
<T> T	onFallbackEmit(HystrixInvokable<T> commandInstance, T value) Invoked when the fallback method in HystrixInvokable emits a value.
<T> java.lang.Exception	onFallbackError(HystrixCommand<T> commandInstance, java.lang.Exception e) Deprecated.
<T> java.lang.Exception	onFallbackError(HystrixInvokable<T> commandInstance, java.lang.Exception e) Invoked when the fallback method in HystrixInvokable fails with an Exception.
<T> void	onFallbackStart(HystrixCommand<T> commandInstance) Deprecated.
<T> void	onFallbackStart(HystrixInvokable<T> commandInstance) Invoked when the fallback method in HystrixInvokable starts.
<T> T	onFallbackSuccess(HystrixCommand<T> commandInstance, T fallbackResponse) Deprecated.
<T> void	onFallbackSuccess(HystrixInvokable<T> commandInstance) Invoked when the user-defined execution method in HystrixInvokable completes successfully.
<T> T	onFallbackSuccess(HystrixInvokable<T> commandInstance, T fallbackResponse) Deprecated.
<T> java.lang.Exception	onRunError(HystrixCommand<T> commandInstance, java.lang.Exception e) Deprecated.
<T> java.lang.Exception	onRunError(HystrixInvokable<T> commandInstance, java.lang.Exception e) Deprecated.
<T> void	onRunStart(HystrixCommand<T> commandInstance) Deprecated.
<T> void	onRunStart(HystrixInvokable<T> commandInstance) Deprecated.
<T> T	onRunSuccess(HystrixCommand<T> commandInstance, T response) Deprecated.
<T> T	onRunSuccess(HystrixInvokable<T> commandInstance, T response) Deprecated.
<T> void	onStart(HystrixCommand<T> commandInstance) Deprecated.
<T> void	onStart(HystrixInvokable<T> commandInstance) Invoked before HystrixInvokable begins executing.
<T> void	onSuccess(HystrixInvokable<T> commandInstance) Invoked when HystrixInvokable finishes a successful execution.
<T> void	onThreadComplete(HystrixCommand<T> commandInstance) Deprecated.
<T> void	onThreadComplete(HystrixInvokable<T> commandInstance) Invoked at completion of thread execution when HystrixCommand is executed using HystrixCommandProperties.ExecutionIsolationStrategy.THREAD.
<T> void	onThreadStart(HystrixCommand<T> commandInstance) Deprecated.
<T> void	onThreadStart(HystrixInvokable<T> commandInstance) Invoked at start of thread execution when HystrixCommand is executed using HystrixCommandProperties.ExecutionIsolationStrategy.THREAD.

Methods inherited from class java.lang.Object

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

Constructor Detail

HystrixCommandExecutionHook

public HystrixCommandExecutionHook()

Method Detail

onStart

public <T> void onStart(HystrixInvokable<T> commandInstance)

Invoked before HystrixInvokable begins executing.

Parameters:

commandInstance - The executing HystrixInvokable instance.

Since:

1.2

onEmit

public <T> T onEmit(HystrixInvokable<T> commandInstance,
                    T value)

Invoked when HystrixInvokable emits a value.

Parameters:

commandInstance - The executing HystrixInvokable instance.

value - value emitted

Since:

1.4

onError

public <T> java.lang.Exception onError(HystrixInvokable<T> commandInstance,
                                       HystrixRuntimeException.FailureType failureType,
                                       java.lang.Exception e)

Invoked when HystrixInvokable fails with an Exception.

Parameters:

commandInstance - The executing HystrixInvokable instance.

failureType - HystrixRuntimeException.FailureType enum representing which type of error

e - exception object

Since:

1.2

onSuccess

public <T> void onSuccess(HystrixInvokable<T> commandInstance)

Invoked when HystrixInvokable finishes a successful execution.

Parameters:

commandInstance - The executing HystrixInvokable instance.

Since:

1.4

onThreadStart

public <T> void onThreadStart(HystrixInvokable<T> commandInstance)

Invoked at start of thread execution when HystrixCommand is executed using HystrixCommandProperties.ExecutionIsolationStrategy.THREAD.

Parameters:

commandInstance - The executing HystrixCommand instance.

Since:

1.2

onThreadComplete

public <T> void onThreadComplete(HystrixInvokable<T> commandInstance)

Invoked at completion of thread execution when HystrixCommand is executed using HystrixCommandProperties.ExecutionIsolationStrategy.THREAD. This will get invoked whenever the Hystrix thread is done executing, regardless of whether the thread finished naturally, or was unsubscribed externally

Parameters:

commandInstance - The executing HystrixCommand instance.

Since:

1.2

onExecutionStart

public <T> void onExecutionStart(HystrixInvokable<T> commandInstance)

Invoked when the user-defined execution method in HystrixInvokable starts.

Parameters:

commandInstance - The executing HystrixInvokable instance.

Since:

1.4

onExecutionEmit

public <T> T onExecutionEmit(HystrixInvokable<T> commandInstance,
                             T value)

Invoked when the user-defined execution method in HystrixInvokable emits a value.

Parameters:

commandInstance - The executing HystrixInvokable instance.

value - value emitted

Since:

1.4

onExecutionError

public <T> java.lang.Exception onExecutionError(HystrixInvokable<T> commandInstance,
                                                java.lang.Exception e)

Invoked when the user-defined execution method in HystrixInvokable fails with an Exception.

Parameters:

commandInstance - The executing HystrixInvokable instance.

e - exception object

Since:

1.4

onExecutionSuccess

public <T> void onExecutionSuccess(HystrixInvokable<T> commandInstance)

Invoked when the user-defined execution method in HystrixInvokable completes successfully.

Parameters:

commandInstance - The executing HystrixInvokable instance.

Since:

1.4

onFallbackStart

public <T> void onFallbackStart(HystrixInvokable<T> commandInstance)

Invoked when the fallback method in HystrixInvokable starts.

Parameters:

commandInstance - The executing HystrixInvokable instance.

Since:

1.2

onFallbackEmit

public <T> T onFallbackEmit(HystrixInvokable<T> commandInstance,
                            T value)

Invoked when the fallback method in HystrixInvokable emits a value.

Parameters:

commandInstance - The executing HystrixInvokable instance.

value - value emitted

Since:

1.4

onFallbackError

public <T> java.lang.Exception onFallbackError(HystrixInvokable<T> commandInstance,
                                               java.lang.Exception e)

Invoked when the fallback method in HystrixInvokable fails with an Exception.

Parameters:

commandInstance - The executing HystrixInvokable instance.

e - exception object

Since:

1.2

onFallbackSuccess

public <T> void onFallbackSuccess(HystrixInvokable<T> commandInstance)

Invoked when the user-defined execution method in HystrixInvokable completes successfully.

Parameters:

commandInstance - The executing HystrixInvokable instance.

Since:

1.4

onCacheHit

public <T> void onCacheHit(HystrixInvokable<T> commandInstance)

Invoked when the command response is found in the HystrixRequestCache.

Parameters:

commandInstance - The executing HystrixCommand

Since:

1.4

onRunStart

@Deprecated
public <T> void onRunStart(HystrixCommand<T> commandInstance)

Deprecated.

DEPRECATED: Change usages of this to onExecutionStart(com.netflix.hystrix.HystrixInvokable<T>). Invoked before HystrixCommand.run() is about to be executed.

Parameters:

commandInstance - The executing HystrixCommand instance.

Since:

1.2

onRunStart

@Deprecated
public <T> void onRunStart(HystrixInvokable<T> commandInstance)

Deprecated.

DEPRECATED: Change usages of this to onExecutionStart(com.netflix.hystrix.HystrixInvokable<T>). Invoked before HystrixCommand.run() is about to be executed.

Parameters:

commandInstance - The executing HystrixCommand instance.

Since:

1.2

onRunSuccess

@Deprecated
public <T> T onRunSuccess(HystrixCommand<T> commandInstance,
                          T response)

Deprecated.

DEPRECATED: Change usages of this to onExecutionEmit(com.netflix.hystrix.HystrixInvokable<T>, T) if you want to add a hook for each value emitted by the command or to onExecutionSuccess(com.netflix.hystrix.HystrixInvokable<T>) if you want to add a hook when the command successfully executes Invoked after successful execution of HystrixCommand.run() with response value. In a HystrixCommand using HystrixCommandProperties.ExecutionIsolationStrategy.THREAD, this will get invoked if the Hystrix thread successfully runs, regardless of whether the calling thread encountered a timeout.

Parameters:

commandInstance - The executing HystrixCommand instance.

response - from HystrixCommand.run()

Returns:

T response object that can be modified, decorated, replaced or just returned as a pass-thru.

Since:

1.2

onRunSuccess

@Deprecated
public <T> T onRunSuccess(HystrixInvokable<T> commandInstance,
                          T response)

Deprecated.

DEPRECATED: Change usages of this to onExecutionEmit(com.netflix.hystrix.HystrixInvokable<T>, T) if you want to add a hook for each value emitted by the command or to onExecutionSuccess(com.netflix.hystrix.HystrixInvokable<T>) if you want to add a hook when the command successfully executes Invoked after successful execution of HystrixCommand.run() with response value. In a HystrixCommand using HystrixCommandProperties.ExecutionIsolationStrategy.THREAD, this will get invoked if the Hystrix thread successfully runs, regardless of whether the calling thread encountered a timeout.

Parameters:

commandInstance - The executing HystrixCommand instance.

response - from HystrixCommand.run()

Returns:

T response object that can be modified, decorated, replaced or just returned as a pass-thru.

Since:

1.2

onRunError

@Deprecated
public <T> java.lang.Exception onRunError(HystrixCommand<T> commandInstance,
                                          java.lang.Exception e)

Deprecated.

DEPRECATED: Change usages of this to onExecutionError(com.netflix.hystrix.HystrixInvokable<T>, java.lang.Exception) Invoked after failed execution of HystrixCommand.run() with thrown Exception.

Parameters:

commandInstance - The executing HystrixCommand instance.

e - Exception thrown by HystrixCommand.run()

Returns:

Exception that can be decorated, replaced or just returned as a pass-thru.

Since:

1.2

onRunError

@Deprecated
public <T> java.lang.Exception onRunError(HystrixInvokable<T> commandInstance,
                                          java.lang.Exception e)

Deprecated.

DEPRECATED: Change usages of this to onExecutionError(com.netflix.hystrix.HystrixInvokable<T>, java.lang.Exception) Invoked after failed execution of HystrixCommand.run() with thrown Exception.

Parameters:

commandInstance - The executing HystrixCommand instance.

e - Exception thrown by HystrixCommand.run()

Returns:

Exception that can be decorated, replaced or just returned as a pass-thru.

Since:

1.2

onFallbackStart

@Deprecated
public <T> void onFallbackStart(HystrixCommand<T> commandInstance)

Deprecated.

DEPRECATED: Change usages of this to onFallbackStart(com.netflix.hystrix.HystrixInvokable<T>) Invoked before HystrixCommand.getFallback() is about to be executed.

Parameters:

commandInstance - The executing HystrixCommand instance.

Since:

1.2

onFallbackSuccess

@Deprecated
public <T> T onFallbackSuccess(HystrixCommand<T> commandInstance,
                               T fallbackResponse)

Deprecated.

DEPRECATED: Change usages of this to onFallbackEmit(com.netflix.hystrix.HystrixInvokable<T>, T) if you want to write a hook that handles each emitted fallback value or to onFallbackSuccess(com.netflix.hystrix.HystrixInvokable<T>) if you want to write a hook that handles success of the fallback method Invoked after successful execution of HystrixCommand.getFallback() with response value.

Parameters:

commandInstance - The executing HystrixCommand instance.

fallbackResponse - from HystrixCommand.getFallback()

Returns:

T response object that can be modified, decorated, replaced or just returned as a pass-thru.

Since:

1.2

onFallbackSuccess

@Deprecated
public <T> T onFallbackSuccess(HystrixInvokable<T> commandInstance,
                               T fallbackResponse)

Deprecated.

DEPRECATED: Change usages of this to onFallbackEmit(com.netflix.hystrix.HystrixInvokable<T>, T) if you want to write a hook that handles each emitted fallback value or to onFallbackSuccess(com.netflix.hystrix.HystrixInvokable<T>) if you want to write a hook that handles success of the fallback method Invoked after successful execution of HystrixCommand.getFallback() with response value.

Parameters:

commandInstance - The executing HystrixCommand instance.

fallbackResponse - from HystrixCommand.getFallback()

Returns:

T response object that can be modified, decorated, replaced or just returned as a pass-thru.

Since:

1.2

onFallbackError

@Deprecated
public <T> java.lang.Exception onFallbackError(HystrixCommand<T> commandInstance,
                                               java.lang.Exception e)

Deprecated.

DEPRECATED: Change usages of this to onFallbackError(com.netflix.hystrix.HystrixInvokable<T>, java.lang.Exception). Invoked after failed execution of HystrixCommand.getFallback() with thrown exception.

Parameters:

commandInstance - The executing HystrixCommand instance.

e - Exception thrown by HystrixCommand.getFallback()

Returns:

Exception that can be decorated, replaced or just returned as a pass-thru.

Since:

1.2

onStart

@Deprecated
public <T> void onStart(HystrixCommand<T> commandInstance)

Deprecated.

DEPRECATED: Change usages of this to onStart(com.netflix.hystrix.HystrixInvokable<T>). Invoked before HystrixCommand executes.

Parameters:

commandInstance - The executing HystrixCommand instance.

Since:

1.2

onComplete

@Deprecated
public <T> T onComplete(HystrixCommand<T> commandInstance,
                        T response)

Deprecated.

DEPRECATED: Change usages of this to onEmit(com.netflix.hystrix.HystrixInvokable<T>, T) if you want to write a hook that handles each emitted command value or to onSuccess(com.netflix.hystrix.HystrixInvokable<T>) if you want to write a hook that handles success of the command Invoked after completion of HystrixCommand execution that results in a response.

The response can come either from HystrixCommand.run() or HystrixCommand.getFallback().

Parameters:

commandInstance - The executing HystrixCommand instance.

response - from HystrixCommand.run() or HystrixCommand.getFallback().

Returns:

T response object that can be modified, decorated, replaced or just returned as a pass-thru.

Since:

1.2

onComplete

@Deprecated
public <T> T onComplete(HystrixInvokable<T> commandInstance,
                        T response)

Deprecated.

DEPRECATED: Change usages of this to onEmit(com.netflix.hystrix.HystrixInvokable<T>, T) if you want to write a hook that handles each emitted command value or to onSuccess(com.netflix.hystrix.HystrixInvokable<T>) if you want to write a hook that handles success of the command Invoked after completion of HystrixCommand execution that results in a response.

The response can come either from HystrixCommand.run() or HystrixCommand.getFallback().

Parameters:

commandInstance - The executing HystrixCommand instance.

response - from HystrixCommand.run() or HystrixCommand.getFallback().

Returns:

T response object that can be modified, decorated, replaced or just returned as a pass-thru.

Since:

1.2

onError

@Deprecated
public <T> java.lang.Exception onError(HystrixCommand<T> commandInstance,
                                       HystrixRuntimeException.FailureType failureType,
                                       java.lang.Exception e)

Deprecated.

DEPRECATED: Change usages of this to onError(com.netflix.hystrix.HystrixInvokable<T>, com.netflix.hystrix.exception.HystrixRuntimeException.FailureType, java.lang.Exception). Invoked after failed completion of HystrixCommand execution.

Parameters:

commandInstance - The executing HystrixCommand instance.

failureType - HystrixRuntimeException.FailureType representing the type of failure that occurred.

See HystrixRuntimeException for more information.

e - Exception thrown by HystrixCommand

Returns:

Exception that can be decorated, replaced or just returned as a pass-thru.

Since:

1.2

onThreadStart

@Deprecated
public <T> void onThreadStart(HystrixCommand<T> commandInstance)

Deprecated.

DEPRECATED: Change usages of this to onThreadStart(com.netflix.hystrix.HystrixInvokable<T>). Invoked at start of thread execution when HystrixCommand is executed using HystrixCommandProperties.ExecutionIsolationStrategy.THREAD.

Parameters:

commandInstance - The executing HystrixCommand instance.

Since:

1.2

onThreadComplete

@Deprecated
public <T> void onThreadComplete(HystrixCommand<T> commandInstance)

Deprecated.

DEPRECATED: Change usages of this to onThreadComplete(com.netflix.hystrix.HystrixInvokable<T>). Invoked at completion of thread execution when HystrixCommand is executed using HystrixCommandProperties.ExecutionIsolationStrategy.THREAD. This will get invoked if the Hystrix thread successfully executes, regardless of whether the calling thread encountered a timeout.

Parameters:

commandInstance - The executing HystrixCommand instance.

Since:

1.2