Github user srdo commented on a diff in the pull request: https://github.com/apache/storm/pull/2538#discussion_r165854164 --- Diff: external/storm-kafka-client/src/main/java/org/apache/storm/kafka/spout/internal/CommitMetadataManager.java --- @@ -0,0 +1,90 @@ +/* + * Copyright 2018 The Apache Software Foundation. + * + * Licensed 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.storm.kafka.spout.internal; + +import com.fasterxml.jackson.core.JsonProcessingException; +import com.fasterxml.jackson.databind.ObjectMapper; +import java.io.IOException; +import java.util.Map; +import org.apache.kafka.clients.consumer.OffsetAndMetadata; +import org.apache.kafka.common.TopicPartition; +import org.apache.storm.kafka.spout.KafkaSpout; +import org.apache.storm.kafka.spout.KafkaSpoutConfig.ProcessingGuarantee; +import org.apache.storm.task.TopologyContext; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** + * Generates and reads commit metadata. + */ +public class CommitMetadataManager { + + private static final ObjectMapper JSON_MAPPER = new ObjectMapper(); + private static final Logger LOG = LoggerFactory.getLogger(CommitMetadata.class); + // Metadata information to commit to Kafka. It is unique per spout instance. --- End diff -- No, the metadata is the same if you create two CommitMetadataManagers from the same spout instance.
---