hadoop/hadoop-common-project/hadoop-common/src/main/proto/RpcHeader.proto

94 lines
3.8 KiB
Protocol Buffer

/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
option java_package = "org.apache.hadoop.ipc.protobuf";
option java_outer_classname = "RpcHeaderProtos";
option java_generate_equals_and_hash = true;
package hadoop.common;
/**
* This is the rpc request header. It is sent with every rpc call.
*
* The format of RPC call is as follows:
* +--------------------------------------------------------------+
* | Rpc length in bytes (4 bytes int) sum of next two parts |
* +--------------------------------------------------------------+
* | RpcRequestHeaderProto - serialized delimited ie has len |
* +--------------------------------------------------------------+
* | RpcRequest The actual rpc request |
* | This request is serialized based on RpcKindProto |
* +--------------------------------------------------------------+
*
*/
/**
* RpcKind determine the rpcEngine and the serialization of the rpc request
*/
enum RpcKindProto {
RPC_BUILTIN = 0; // Used for built in calls by tests
RPC_WRITABLE = 1; // Use WritableRpcEngine
RPC_PROTOCOL_BUFFER = 2; // Use ProtobufRpcEngine
}
message RpcRequestHeaderProto { // the header for the RpcRequest
enum OperationProto {
RPC_FINAL_PACKET = 0; // The final RPC Packet
RPC_CONTINUATION_PACKET = 1; // not implemented yet
RPC_CLOSE_CONNECTION = 2; // close the rpc connection
}
optional RpcKindProto rpcKind = 1;
optional OperationProto rpcOp = 2;
required uint32 callId = 3; // each rpc has a callId that is also used in response
}
/**
* Rpc Response Header
* ** If request is successfull response is returned as below ********
* +------------------------------------------------------------------+
* | Rpc reponse length in bytes (4 bytes int) |
* | (sum of next two parts) |
* +------------------------------------------------------------------+
* | RpcResponseHeaderProto - serialized delimited ie has len |
* +------------------------------------------------------------------+
* | if request is successful: |
* | - RpcResponse - The actual rpc response bytes follow |
* the response header |
* | This response is serialized based on RpcKindProto |
* | if request fails : |
* | The rpc response header contains the necessary info |
* +------------------------------------------------------------------+
*
*/
message RpcResponseHeaderProto {
enum RpcStatusProto {
SUCCESS = 0; // RPC succeeded
ERROR = 1; // RPC Failed
FATAL = 2; // Fatal error - connection is closed
}
required uint32 callId = 1; // callId used in Request
required RpcStatusProto status = 2;
optional uint32 serverIpcVersionNum = 3; // Sent if success or fail
optional string exceptionClassName = 4; // if request fails
optional string errorMsg = 5; // if request fails, often contains strack trace
}