helix-core/src/main/java/org/apache/helix/controller/rebalancer/waged/constraints/FaultZoneAwareConstraint.java

package org.apache.helix.controller.rebalancer.waged.constraints;

/*
 * 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.
 */

import org.apache.helix.controller.rebalancer.waged.model.AssignableNode;
import org.apache.helix.controller.rebalancer.waged.model.AssignableReplica;
import org.apache.helix.controller.rebalancer.waged.model.ClusterContext;

class FaultZoneAwareConstraint extends HardConstraint {

  @Override
  boolean isAssignmentValid(AssignableNode node, AssignableReplica replica,
      ClusterContext clusterContext) {
    if (!node.hasFaultZone()) {
      return true;
    }
    return !clusterContext
        .getPartitionsForResourceAndFaultZone(replica.getResourceName(), node.getFaultZone())
        .contains(replica.getPartitionName());
  }

  @Override
  String getDescription() {
    return "A fault zone cannot contain more than 1 replica of same partition";
  }
}