Class CheckpointingQueryEngine

Reactive event processing query engine that supports checkpointing.

Inheritance

System.Object

CheckpointingQueryEngine

Implements

ICheckpointingQueryEngine

IReliableQueryEngine

IQueryEngine

ICheckpointable

System.IAsyncDisposable

System.IDisposable

Namespace: Reaqtor.QueryEngine

Assembly: Reaqtor.QueryEngine.dll

Syntax

public class CheckpointingQueryEngine : Object, ICheckpointingQueryEngine, IReliableQueryEngine, IQueryEngine, ICheckpointable, IAsyncDisposable, IDisposable

Constructors

CheckpointingQueryEngine(Uri, IReactiveServiceResolver, IScheduler, IReactiveMetadata, IKeyValueStore, ISerializationPolicy, IQuotedTypeConversionTargets, TraceSource, ICompiledDelegateCache)

Creates a new event processing engine that supports checkpointing.

Declaration

public CheckpointingQueryEngine(Uri uri, IReactiveServiceResolver serviceResolver, IScheduler scheduler, IReactiveMetadata metadataRegistry, IKeyValueStore keyValueStore, ISerializationPolicy serializationPolicy, IQuotedTypeConversionTargets quotedTypeConversionTargets, TraceSource traceSource = null, ICompiledDelegateCache delegateCache = null)

Parameters

Type	Name	Description
System.Uri	uri	URI identifying the engine. This URI should be unique across the cluster.
IReactiveServiceResolver	serviceResolver	Resolver used by the engine to locate artifacts in reactive services across the cluster.
IScheduler	scheduler	Scheduler used by the engine to process events and to run maintenance operations.
IReactiveMetadata	metadataRegistry	Metadata registry used by the engine to retrieve definitions of artifacts.
IKeyValueStore	keyValueStore	Key value store used for persistent storage of the engine's state.
ISerializationPolicy	serializationPolicy	Serialization policy used to manage state serialization.
IQuotedTypeConversionTargets	quotedTypeConversionTargets	Supplies an external mapping used to unquote query operators.
System.Diagnostics.TraceSource	traceSource	Trace source used by the engine to write diagnostic information.
ICompiledDelegateCache	delegateCache	Compiled delegate cache used to optimize compilation of expressions. A cache may be shared across engines on the same host.

Properties

HasUnloadStarted

Gets whether an unload operation has been initiated on the engine.

Declaration

public bool HasUnloadStarted { get; }

Property Value

Type	Description
System.Boolean

Options

Gets an object exposing configuration options that can be set on the engine.

Declaration

public ConfigurationOptions Options { get; }

Property Value

Type	Description
ConfigurationOptions

ReactiveService

Gets the reactive service exposed by the engine.

Declaration

public IReactive ReactiveService { get; }

Property Value

Type	Description
IReactive

ReliableReactiveService

Gets the reliable reactive service exposed by the engine.

Declaration

public IReliableReactive ReliableReactiveService { get; }

Property Value

Type	Description
IReliableReactive

Scheduler

Gets the scheduler used by the engine to process events and run maintenance operations.

Declaration

public IScheduler Scheduler { get; }

Property Value

Type	Description
IScheduler

Remarks

This scheduler may be paused and resumed by the engine at various times and should not be used to schedule work that's not related to this engine instance.

ServiceProvider

Get the reactive provider exposed by the engine.

Declaration

public IReactiveServiceProvider ServiceProvider { get; }

Property Value

Type	Description
IReactiveServiceProvider

Status

Gets the current status of the engine.

Declaration

public QueryEngineStatus Status { get; }

Property Value

Type	Description
QueryEngineStatus

TraceSource

Gets the trace source used by the engine to write diagnostic information.

Declaration

public TraceSource TraceSource { get; }

Property Value

Type	Description
System.Diagnostics.TraceSource

Uri

Gets the URI identifying the engine.

Declaration

public Uri Uri { get; }

Property Value

Type	Description
System.Uri

Methods

CheckpointAsync(IStateWriter, CancellationToken, IProgress<Int32>)

Saves the state of the event processing engine to a store.

Declaration

public Task CheckpointAsync(IStateWriter writer, CancellationToken token = null, IProgress<int> progress = null)

Parameters

Type	Name	Description
IStateWriter	writer	Writer to save state to.
System.Threading.CancellationToken	token	Cancellation token to observe cancellation requests.
System.IProgress<System.Int32>	progress	Progress indicator reporting progress percentages.

Returns

Type	Description
System.Threading.Tasks.Task	Task to observe the eventual completion of the operation.

CreateOperatorContext(Uri)

Processes a request to create an operator context to thread through an initialized artifact using SetContext.

Declaration

protected virtual IHostedOperatorContext CreateOperatorContext(Uri instanceId)

Parameters

Type	Name	Description
System.Uri	instanceId	URI identifying the artifact instance that will receive the operator context.

Returns

Type	Description
IHostedOperatorContext	Operator context that will be passed to the artifact during its initialization using SetContext.

Dispose()

Disposes resources.

Declaration

public void Dispose()

Dispose(Boolean)

Disposes resources.

Declaration

protected virtual void Dispose(bool disposing)

Parameters

Type	Name	Description
System.Boolean	disposing	true if called from System.IDisposable.Dispose; otherwise, false.

DisposeAsync()

Disposes resources asynchronously.

Declaration

public ValueTask DisposeAsync()

Returns

Type	Description
System.Threading.Tasks.ValueTask	A task to await the completion of the dispose operation.

DisposeAsyncCore()

Disposes resources asynchronously.

Declaration

protected virtual ValueTask DisposeAsyncCore()

Returns

Type	Description
System.Threading.Tasks.ValueTask	A task to await the completion of the dispose operation.

RecoverAsync(IStateReader, CancellationToken, IProgress<Int32>)

Recovers the state of the event processing engine from a store.

Declaration

public Task RecoverAsync(IStateReader reader, CancellationToken token = null, IProgress<int> progress = null)

Parameters

Type	Name	Description
IStateReader	reader	Reader to load state from.
System.Threading.CancellationToken	token	Cancellation token to observe cancellation requests.
System.IProgress<System.Int32>	progress	Progress indicator reporting progress percentages.

Returns

Type	Description
System.Threading.Tasks.Task	Task to observe the eventual completion of the operation.

UnloadAsync(IProgress<Int32>)

Unloads the event processing engine.

Declaration

public Task UnloadAsync(IProgress<int> progress = null)

Parameters

Type	Name	Description
System.IProgress<System.Int32>	progress	Progress indicator reporting progress percentages.

Returns

Type	Description
System.Threading.Tasks.Task	Task to observe the eventual completion of the operation.

Events

EntityCreated

An event triggered when a runtime entity is created.

Declaration

public event EventHandler<ReactiveEntityEventArgs> EntityCreated

Event Type

Type	Description
System.EventHandler<ReactiveEntityEventArgs>

EntityDefined

An event triggered when a definition entity is defined.

Declaration

public event EventHandler<ReactiveEntityEventArgs> EntityDefined

Event Type

Type	Description
System.EventHandler<ReactiveEntityEventArgs>

EntityDeleted

An event triggered when a runtime entity is deleted.

Declaration

public event EventHandler<ReactiveEntityEventArgs> EntityDeleted

Event Type

Type	Description
System.EventHandler<ReactiveEntityEventArgs>

EntityLoadFailed

An event triggered when a runtime entity failed to load during recovery.

Declaration

public event EventHandler<ReactiveEntityLoadFailedEventArgs> EntityLoadFailed

Event Type

Type	Description
System.EventHandler<ReactiveEntityLoadFailedEventArgs>

EntityReplayFailed

An event triggered when a runtime entity failed to save during checkpointing.

Declaration

public event EventHandler<ReactiveEntityReplayFailedEventArgs> EntityReplayFailed

Event Type

Type	Description
System.EventHandler<ReactiveEntityReplayFailedEventArgs>

EntitySaveFailed

An event triggered when a runtime entity failed to save during checkpointing.

Declaration

public event EventHandler<ReactiveEntitySaveFailedEventArgs> EntitySaveFailed

Event Type

Type	Description
System.EventHandler<ReactiveEntitySaveFailedEventArgs>

EntityUndefined

An event triggered when a definition entity is undefined.

Declaration

public event EventHandler<ReactiveEntityEventArgs> EntityUndefined

Event Type

Type	Description
System.EventHandler<ReactiveEntityEventArgs>

SchedulerContinued

An event triggered when the scheduler for the query engine has continued.

Declaration

public event EventHandler<SchedulerContinuedEventArgs> SchedulerContinued

Event Type

Type	Description
System.EventHandler<SchedulerContinuedEventArgs>

SchedulerContinuing

An event triggered when the scheduler for the query engine is continuing.

Declaration

public event EventHandler<SchedulerContinuingEventArgs> SchedulerContinuing

Event Type

Type	Description
System.EventHandler<SchedulerContinuingEventArgs>

SchedulerPaused

An event triggered when the scheduler for the query engine has been paused.

Declaration

public event EventHandler<SchedulerPausedEventArgs> SchedulerPaused

Event Type

Type	Description
System.EventHandler<SchedulerPausedEventArgs>

SchedulerPausing

An event triggered when the scheduler for the query engine is pausing.

Declaration

public event EventHandler<SchedulerPausingEventArgs> SchedulerPausing

Event Type

Type	Description
System.EventHandler<SchedulerPausingEventArgs>

Implements

ICheckpointingQueryEngine

IReliableQueryEngine

IQueryEngine

ICheckpointable

System.IAsyncDisposable

System.IDisposable