Class PipelineManager

java.lang.Object

io.aleph0.yap.core.pipeline.PipelineManager

All Implemented Interfaces:

Measureable<PipelineManager.Metrics>, Runnable

public class PipelineManager
extends Object
implements Measureable<PipelineManager.Metrics>, Runnable

PipelineManager is a class that manages the lifecycle of a Pipeline, including ask lifecycle and lifecycle listeners. It is designed to be used in a multi-threaded environment and provides methods for managing tasks.

The PipelineManager delegates decision making to a PipelineController instance, which is responsible for deciding what actions to take based on the current state of the pipeline and workers, and the PipelineManager is responsible for executing those actions.

Internally, the PipelineManager models the task state as a finite state machine with the following states:

                                  
     READY ─► RUNNING ─► COMPLETED
               │  │               
               │  └────► CANCELLED
               │                  
               └───────► FAILED
 
 

To ensure correctness, it enforces that the pipeline can only perform the above transitions between states. (So, for example, the PipelineManager will fail if the controller attempts to transition from COMPLETED to RUNNING or from FAILED to CANCELLED.) Within the boundaries of these constraints, the PipelineController is free to decide what actions to take.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	PipelineManager.LifecycleListener
static final record	PipelineManager.Metrics
static enum	PipelineManager.PipelinePhase
static enum	PipelineManager.PipelineState

Constructor Summary

Constructors

Constructor	Description
PipelineManager(int id, ExecutorService executor, PipelineController controller, List<TaskManager<?>> tasks)

Method Summary

Modifier and Type	Method	Description
void	addLifecycleListener(PipelineManager.LifecycleListener listener)
PipelineManager.Metrics	checkMetrics()	Non-destructive check of the metrics.
PipelineManager.Metrics	flushMetrics()	Destructive read of the metrics.
int	getId()
void	removeLifecycleListener(PipelineManager.LifecycleListener listener)
void	run()	Runs the pipeline manager, managing the lifecycle of the pipeline and its tasks.
String	toString()	Overriden to provide a thread name for easier debugging.

Methods inherited from class java.lang.Object

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

Constructor Details

PipelineManager

public PipelineManager(int id,
 ExecutorService executor,
 PipelineController controller,
 List<TaskManager<?>> tasks)

Method Details

getId

public int getId()

addLifecycleListener

public void addLifecycleListener(PipelineManager.LifecycleListener listener)

removeLifecycleListener

public void removeLifecycleListener(PipelineManager.LifecycleListener listener)

run

public void run()

Runs the pipeline manager, managing the lifecycle of the pipeline and its tasks.

Specified by:

run in interface Runnable

Throws:

PipelineExecutionException - if the pipeline fails normally

PipelineCanceledException - if the pipeline is cancelled

PipelineErrorException - if the pipeline fails due to an internal error

checkMetrics

public PipelineManager.Metrics checkMetrics()

Description copied from interface: Measureable

Non-destructive check of the metrics. This should be used to check the state of metrics without clearing them, for example in a TaskController.

Specified by:

checkMetrics in interface Measureable<PipelineManager.Metrics>

Returns:

the metrics

flushMetrics

public PipelineManager.Metrics flushMetrics()

Description copied from interface: Measureable

Destructive read of the metrics. This should be used to check and reset the state of metrics, for example by the metrics checking thread.

Specified by:

flushMetrics in interface Measureable<PipelineManager.Metrics>

Returns:

the metrics

toString

public String toString()

Overriden to provide a thread name for easier debugging.

Overrides:

toString in class Object

See Also:

• PipelineBuilder.defaultVirtualThreadExecutorService()
• PipelineBuilder.defaultPlatformThreadExecutorService()