alluxio

Class RpcUtils

java.lang.Object

alluxio.RpcUtils

public final class RpcUtils
extends Object

Utilities for handling server RPC calls. There are two types of RPC calls: 1. RPCs that only throw IOException 2. Streaming RPCs For each of these, if failureOk is set, non-fatal errors will only be logged at the DEBUG level and failure metrics will not be recorded.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	RpcUtils.RpcCallableThrowsIOException<T> An interface representing a callable which can only throw Alluxio or IO exceptions.
static interface	RpcUtils.StreamingRpcCallable<T> An interface representing a streaming RPC callable.

Method Summary

Modifier and Type	Method and Description
static <T> void	call(org.slf4j.Logger logger, RpcUtils.RpcCallableThrowsIOException<T> callable, String methodName, boolean failureOk, String description, io.grpc.stub.StreamObserver<T> responseObserver, Object... args) Calls the given RpcUtils.RpcCallableThrowsIOException and handles any exceptions thrown.
static <T> void	call(org.slf4j.Logger logger, RpcUtils.RpcCallableThrowsIOException<T> callable, String methodName, String description, io.grpc.stub.StreamObserver<T> responseObserver, Object... args) Calls the given RpcUtils.RpcCallableThrowsIOException and handles any exceptions thrown.
static <T> T	callAndReturn(org.slf4j.Logger logger, RpcUtils.RpcCallableThrowsIOException<T> callable, String methodName, boolean failureOk, String description, Object... args) Calls the given RpcUtils.RpcCallableThrowsIOException and returns its result.
static <T> void	streamingRPCAndLog(org.slf4j.Logger logger, RpcUtils.StreamingRpcCallable<T> callable, String methodName, boolean sendResponse, boolean completeResponse, io.grpc.stub.StreamObserver<T> responseObserver, String description, Object... args) Handles a streaming RPC callable with logging.

Methods inherited from class java.lang.Object

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

Method Detail

call

public static <T> void call(org.slf4j.Logger logger,
                            RpcUtils.RpcCallableThrowsIOException<T> callable,
                            String methodName,
                            String description,
                            io.grpc.stub.StreamObserver<T> responseObserver,
                            Object... args)

Calls the given RpcUtils.RpcCallableThrowsIOException and handles any exceptions thrown. If the RPC fails, a warning or error will be logged.

Type Parameters:

T - the return type of the callable

Parameters:

logger - the logger to use for this call

callable - the callable to call

methodName - the name of the method, used for metrics

description - the format string of the description, used for logging

responseObserver - gRPC response observer

args - the arguments for the description

call

public static <T> void call(org.slf4j.Logger logger,
                            RpcUtils.RpcCallableThrowsIOException<T> callable,
                            String methodName,
                            boolean failureOk,
                            String description,
                            io.grpc.stub.StreamObserver<T> responseObserver,
                            Object... args)

Calls the given RpcUtils.RpcCallableThrowsIOException and handles any exceptions thrown. The failureOk parameter indicates whether or not AlluxioExceptions and IOExceptions are expected results (for example it would be false for the exists() call). In this case, we do not log the failure or increment failure metrics. When a RuntimeException is thrown, we always treat it as a failure and log an error and increment metrics.

Type Parameters:

T - the return type of the callable

Parameters:

logger - the logger to use for this call

callable - the callable to call

methodName - the name of the method, used for metrics

failureOk - whether failures are expected (affects logging and metrics)

description - the format string of the description, used for logging

responseObserver - gRPC response observer

args - the arguments for the description

callAndReturn

public static <T> T callAndReturn(org.slf4j.Logger logger,
                                  RpcUtils.RpcCallableThrowsIOException<T> callable,
                                  String methodName,
                                  boolean failureOk,
                                  String description,
                                  Object... args)
                           throws io.grpc.StatusException

Calls the given RpcUtils.RpcCallableThrowsIOException and returns its result. Exceptions are logged, accounted for in metrics and then rethrown at the end. The failureOk parameter indicates whether or not AlluxioExceptions and IOExceptions are expected results (for example it would be false for the exists() call). In this case, we do not log the failure or increment failure metrics. When a RuntimeException is thrown, we always treat it as a failure and log an error and increment metrics.

Type Parameters:

T - the return type of the callable

Parameters:

logger - the logger to use for this call

callable - the callable to call

methodName - the name of the method, used for metrics

failureOk - whether failures are expected (affects logging and metrics)

description - the format string of the description, used for logging

args - the arguments for the description

Returns:

the result. (Null if failed)

Throws:

io.grpc.StatusException

streamingRPCAndLog

public static <T> void streamingRPCAndLog(org.slf4j.Logger logger,
                                          RpcUtils.StreamingRpcCallable<T> callable,
                                          String methodName,
                                          boolean sendResponse,
                                          boolean completeResponse,
                                          io.grpc.stub.StreamObserver<T> responseObserver,
                                          String description,
                                          Object... args)

Handles a streaming RPC callable with logging.

Type Parameters:

T - the return type of the callable

Parameters:

logger - the logger to use for this call

callable - the callable to call

methodName - the name of the method, used for metrics

sendResponse - whether a response should send to the client

completeResponse - whether onComplete should be called on the response observer

responseObserver - gRPC response observer

description - the format string of the description, used for logging

args - the arguments for the description