java.lang.Object
- org.apache.beam.runners.fnexecution.control.FnApiControlClient

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, InstructionRequestHandler
```
public class FnApiControlClient
extends java.lang.Object
implements java.io.Closeable, InstructionRequestHandler
```
A client for the control plane of an SDK harness, which can issue requests to it over the Fn API.
This class presents a low-level Java API de-inverting the Fn API's gRPC layer.
The Fn API is inverted so the runner is the server and the SDK harness is the client, for firewalling reasons (the runner may execute in a more privileged environment forbidding outbound connections).
This low-level client is responsible only for correlating requests with responses.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`org.apache.beam.vendor.grpc.v1p48p1.io.grpc.stub.StreamObserver<org.apache.beam.model.fnexecution.v1.BeamFnApi.InstructionResponse>`	`asResponseObserver()`
`void`	`close()`
`static FnApiControlClient`	`forRequestObserver(java.lang.String workerId, org.apache.beam.vendor.grpc.v1p48p1.io.grpc.stub.StreamObserver<org.apache.beam.model.fnexecution.v1.BeamFnApi.InstructionRequest> requestObserver, java.util.concurrent.ConcurrentMap<java.lang.String,org.apache.beam.model.fnexecution.v1.BeamFnApi.ProcessBundleDescriptor> processBundleDescriptors)`	Returns a `FnApiControlClient` which will submit its requests to the provided observer.
`org.apache.beam.model.fnexecution.v1.BeamFnApi.ProcessBundleDescriptor`	`getProcessBundleDescriptor(java.lang.String id)`
`java.lang.String`	`getWorkerId()`
`java.util.concurrent.CompletionStage<org.apache.beam.model.fnexecution.v1.BeamFnApi.InstructionResponse>`	`handle(org.apache.beam.model.fnexecution.v1.BeamFnApi.InstructionRequest request)`
`void`	`onClose(java.util.function.Consumer<FnApiControlClient> onCloseListener)`
`void`	`registerProcessBundleDescriptor(org.apache.beam.model.fnexecution.v1.BeamFnApi.ProcessBundleDescriptor processBundleDescriptor)`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

forRequestObserver

public static FnApiControlClient forRequestObserver(java.lang.String workerId,
                                                    org.apache.beam.vendor.grpc.v1p48p1.io.grpc.stub.StreamObserver<org.apache.beam.model.fnexecution.v1.BeamFnApi.InstructionRequest> requestObserver,
                                                    java.util.concurrent.ConcurrentMap<java.lang.String,org.apache.beam.model.fnexecution.v1.BeamFnApi.ProcessBundleDescriptor> processBundleDescriptors)

Returns a FnApiControlClient which will submit its requests to the provided observer.

It is the responsibility of the caller to register this object as an observer of incoming responses (this will generally be done as part of fulfilling the contract of a gRPC service).

handle

public java.util.concurrent.CompletionStage<org.apache.beam.model.fnexecution.v1.BeamFnApi.InstructionResponse> handle(org.apache.beam.model.fnexecution.v1.BeamFnApi.InstructionRequest request)

Specified by:: handle in interface InstructionRequestHandler

asResponseObserver

public org.apache.beam.vendor.grpc.v1p48p1.io.grpc.stub.StreamObserver<org.apache.beam.model.fnexecution.v1.BeamFnApi.InstructionResponse> asResponseObserver()

getProcessBundleDescriptor

public org.apache.beam.model.fnexecution.v1.BeamFnApi.ProcessBundleDescriptor getProcessBundleDescriptor(java.lang.String id)

registerProcessBundleDescriptor

public void registerProcessBundleDescriptor(org.apache.beam.model.fnexecution.v1.BeamFnApi.ProcessBundleDescriptor processBundleDescriptor)

Specified by:: registerProcessBundleDescriptor in interface InstructionRequestHandler

close
```
public void close()
```
Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in interface java.io.Closeable

getWorkerId
```
public java.lang.String getWorkerId()
```

onClose

public void onClose(java.util.function.Consumer<FnApiControlClient> onCloseListener)

Class FnApiControlClient