org.apache.beam.runners.fnexecution.control

Interface ControlClientPool

All Known Implementing Classes:

MapControlClientPool

@ThreadSafe
public interface ControlClientPool

A pool of control clients that brokers incoming SDK harness connections (in the form of InstructionRequestHandlers.

Incoming instruction handlers usually come from the control plane gRPC service. Typical use:

   // Within owner of the pool, who may or may not own the control plane server as well
   ControlClientPool pool = ...
   FnApiControlClientPoolService service =
       FnApiControlClientPoolService.offeringClientsToSink(pool.getSink(), headerAccessor)
   // Incoming gRPC control connections will now be added to the client pool.

   // Within code that interacts with the instruction handler. The get call blocks until an
   // incoming client is available:
   ControlClientSource clientSource = ... InstructionRequestHandler
   instructionHandler = clientSource.get("worker-id");
 

All ControlClientPool implementations must be thread-safe.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	ControlClientPool.Sink A sink for InstructionRequestHandlers keyed by worker id.
static interface	ControlClientPool.Source A source of InstructionRequestHandlers.

Method Summary

Modifier and Type	Method and Description
ControlClientPool.Sink	getSink() Sink for control clients.
ControlClientPool.Source	getSource() Source of control clients.

Method Detail

getSink

ControlClientPool.Sink getSink()

Sink for control clients.

getSource

ControlClientPool.Source getSource()

Source of control clients.