Github user markap14 commented on a diff in the pull request: https://github.com/apache/nifi/pull/2947#discussion_r220976418 --- Diff: nifi-nar-bundles/nifi-framework-bundle/nifi-framework/nifi-framework-core/src/main/java/org/apache/nifi/controller/queue/clustered/partition/FlowFilePartitioner.java --- @@ -0,0 +1,53 @@ +/* + * 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.nifi.controller.queue.clustered.partition; + +import org.apache.nifi.controller.repository.FlowFileRecord; + +public interface FlowFilePartitioner { + + /** + * Determines which partition the given FlowFile should go to + * + * @param flowFile the FlowFile to partition + * @param partitions the partitions to choose from + * @param localPartition the local partition, which is also included in the given array of partitions + * @return the partition for the FlowFile + */ + QueuePartition getPartition(FlowFileRecord flowFile, QueuePartition[] partitions, QueuePartition localPartition); + + /** + * @return <code>true</code> if a change in the size of a cluster should result in re-balancing all FlowFiles in queue, + * <code>false</code> if a change in the size of a cluster does not require re-balancing. + */ + boolean isRebalanceOnClusterResize(); --- End diff -- I disagree - I think we should stick with standard java convention is `isXYZ()` being a simple method that returns a boolean.
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