| /** |
| * 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. |
| */ |
| package org.apache.hadoop.ipc; |
| |
| import java.nio.ByteBuffer; |
| import java.nio.charset.StandardCharsets; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| |
| @InterfaceAudience.Private |
| public class RpcConstants { |
| private RpcConstants() { |
| // Hidden Constructor |
| } |
| |
| public static final int AUTHORIZATION_FAILED_CALL_ID = -1; |
| public static final int INVALID_CALL_ID = -2; |
| public static final int CONNECTION_CONTEXT_CALL_ID = -3; |
| public static final int PING_CALL_ID = -4; |
| |
| public static final byte[] DUMMY_CLIENT_ID = new byte[0]; |
| |
| public static final int INVALID_RETRY_COUNT = -1; |
| |
| /** |
| * The first four bytes of Hadoop RPC connections |
| */ |
| public static final ByteBuffer HEADER = |
| ByteBuffer.wrap("hrpc".getBytes(StandardCharsets.UTF_8)); |
| |
| // 1 : Introduce ping and server does not throw away RPCs |
| // 3 : Introduce the protocol into the RPC connection header |
| // 4 : Introduced SASL security layer |
| // 5 : Introduced use of {@link ArrayPrimitiveWritable$Internal} |
| // in ObjectWritable to efficiently transmit arrays of primitives |
| // 6 : Made RPC Request header explicit |
| // 7 : Changed Ipc Connection Header to use Protocol buffers |
| // 8 : SASL server always sends a final response |
| // 9 : Changes to protocol for HADOOP-8990 |
| public static final byte CURRENT_VERSION = 9; |
| } |