geode-core/src/main/java/org/apache/geode/internal/cache/partitioned/rebalance/BucketOperator.java

/*
 * 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.geode.internal.cache.partitioned.rebalance;

import java.util.Map;

import org.apache.geode.distributed.internal.membership.InternalDistributedMember;

/**
 * A BucketOperator is used by the PartitionedRegionLoadModel to perform the actual operations such
 * as moving a bucket or creating a redundant copy.
 *
 */
public interface BucketOperator {

  /**
   * Create a redundancy copy of a bucket on a given node. This call may be asynchronous, it will
   * notify the completion when the the operation is done.
   *
   * Note that the completion is not required to be threadsafe, so implementors should ensure the
   * completion is invoked by the calling thread of createRedundantBucket, usually by invoking the
   * completions in waitForOperations.
   *
   * @param targetMember the node to create the bucket on
   * @param bucketId the id of the bucket to create
   * @param colocatedRegionBytes the size of the bucket in bytes
   * @param completion a callback which will receive a notification on the success or failure of the
   *        operation.
   */
  void createRedundantBucket(InternalDistributedMember targetMember, int bucketId,
      Map<String, Long> colocatedRegionBytes, Completion completion);

  /**
   * Remove a bucket from the target member.
   */
  boolean removeBucket(InternalDistributedMember memberId, int id,
      Map<String, Long> colocatedRegionSizes);

  /**
   * Move a bucket from one member to another
   *
   * @param sourceMember The member we want to move the bucket off of.
   * @param targetMember The member we want to move the bucket too.
   * @param bucketId the id of the bucket we want to move
   * @return true if the bucket was moved successfully
   */
  boolean moveBucket(InternalDistributedMember sourceMember, InternalDistributedMember targetMember,
      int bucketId, Map<String, Long> colocatedRegionBytes);

  /**
   * Move a primary from one node to another. This method will not be called unless both nodes are
   * hosting the bucket, and the source node is the primary for the bucket.
   *
   * @param source The old primary for the bucket
   * @param target The new primary for the bucket
   * @param bucketId The id of the bucket to move;
   * @return true if the primary was successfully moved.
   */
  boolean movePrimary(InternalDistributedMember source, InternalDistributedMember target,
      int bucketId);

  /**
   * Wait for any pending asynchronous operations that this thread submitted earlier to complete.
   * Currently only createRedundantBucket may be asynchronous.
   */
  void waitForOperations();

  /**
   * Callbacks for asnychonous operations. These methods will be invoked when an ansynchronous
   * operation finishes.
   *
   * The completions are NOT THREADSAFE.
   *
   * They will be completed when createRedundantBucket or waitForOperations is called.
   */
  interface Completion {
    void onSuccess();

    void onFailure();
  }
}