hadoop/hadoop-hdfs-project/hadoop-hdfs-client/src/main/proto/StorageContainerLocationProtocol.proto

/**
 * 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.
 */

/**
 * These .proto interfaces are private and unstable.
 * Please see http://wiki.apache.org/hadoop/Compatibility
 * for what changes are allowed for a *unstable* .proto interface.
 */

option java_package = "org.apache.hadoop.ozone.protocol.proto";
option java_outer_classname = "StorageContainerLocationProtocolProtos";
option java_generic_services = true;
option java_generate_equals_and_hash = true;
package hadoop.hdfs;

import "hdfs.proto";
import "DatanodeContainerProtocol.proto";

/**
 * keys - batch of object keys to find
 */
message GetStorageContainerLocationsRequestProto {
  repeated string keys = 1;
}

/**
 * locatedContainers - for each requested hash, nodes that currently host the
 *     container for that object key hash
 */
message GetStorageContainerLocationsResponseProto {
  repeated LocatedContainerProto locatedContainers = 1;
}

/**
 * Holds the nodes that currently host the container for an object key.
 */
message LocatedContainerProto {
  required string key = 1;
  required string matchedKeyPrefix = 2;
  required string containerName = 3;
  repeated DatanodeInfoProto locations = 4;
  required DatanodeInfoProto leader = 5;
}

/**
* Request send to SCM asking where the container should be created.
*/
message ContainerRequestProto {
  required string containerName = 1;
  // Ozone only support replciation of either 1 or 3.
  enum ReplicationFactor {
    ONE = 1;
    THREE = 3;
  }
  required ReplicationFactor replicationFactor = 2;
}

/**
 * Reply from SCM indicating that the container.
 */
message ContainerResponseProto {
  enum Error {
    success = 1;
    errorContainerAlreadyExists = 2;
    errorContainerMissing = 3;
  }
  required Error errorCode = 1;
  required hadoop.hdfs.ozone.Pipeline pipeline = 2;
  optional string errorMessage = 3;
}

// SCM Block protocol
/**
 * keys - batch of block keys to find
 */
message GetScmBlockLocationsRequestProto {
  repeated string keys = 1;
}

/**
 * locatedBlocks - for each requested hash, nodes that currently host the
 *     container for that object key hash
 */
message GetScmBlockLocationsResponseProto {
  repeated ScmLocatedBlockProto locatedBlocks = 1;
}

/**
 * Holds the nodes that currently host the blocks for a key.
 */
message ScmLocatedBlockProto {
  required string key = 1;
  required hadoop.hdfs.ozone.Pipeline pipeline = 2;
}

/**
* Request send to SCM asking allocate block of specified size.
*/
message AllocateScmBlockRequestProto {
  required uint64 size = 1;
}

/**
 * Reply from SCM indicating that the container.
 */
message AllocateScmBlockResponseProto {
  enum Error {
    success = 1;
    errorNotEnoughSpace = 2;
    errorSizeTooBig = 3;
    unknownFailure = 4;
  }
  required Error errorCode = 1;
  required string key = 2;
  required hadoop.hdfs.ozone.Pipeline pipeline = 3;
  required bool createContainer = 4;
  optional string errorMessage = 5;
}

/**
 * Protocol used from an HDFS node to StorageContainerManager.  See the request
 * and response messages for details of the RPC calls.
 */
service StorageContainerLocationProtocolService {
  /**
   * Find the set of nodes that currently host the container of an object, as
   * identified by the object key hash.  This method supports batch lookup by
   * passing multiple key hashes.
   */
  rpc getStorageContainerLocations(GetStorageContainerLocationsRequestProto)
      returns(GetStorageContainerLocationsResponseProto);

  /**
   Creates a container entry in SCM.
   */
  rpc allocateContainer(ContainerRequestProto) returns (ContainerResponseProto);


  /**
   * Find the set of nodes that currently host the block, as
   * identified by the key.  This method supports batch lookup by
   * passing multiple keys.
   */
  rpc getScmBlockLocations(GetScmBlockLocationsRequestProto)
      returns(GetScmBlockLocationsResponseProto);

  /**
   Creates a block entry in SCM.
   */
  rpc allocateScmBlock(AllocateScmBlockRequestProto)
      returns (AllocateScmBlockResponseProto);
}