Mailing-List: contact dev-help@apex.apache.org; run by ezmlm
Precedence: bulk
Reply-To: dev@apex.apache.org
Date: Fri, 10 Jun 2016 23:29:20 +0000 (UTC)
From: "ASF GitHub Bot (JIRA)" <jira@apache.org>
To: dev@apex.incubator.apache.org
Message-ID: <JIRA.12968045.1463002767000.59289.1465601360988@Atlassian.JIRA>
In-Reply-To: <JIRA.12968045.1463002767000@Atlassian.JIRA>
References: <JIRA.12968045.1463002767000@Atlassian.JIRA> <JIRA.12968045.1463002767176@arcas>
Subject: [jira] [Commented] (APEXMALHAR-2086) Kafka Output Operator with
 Kafka 0.9 API
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit
archived-at: Fri, 10 Jun 2016 23:29:27 -0000


    [ https://issues.apache.org/jira/browse/APEXMALHAR-2086?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15325498#comment-15325498 ] 

ASF GitHub Bot commented on APEXMALHAR-2086:
--------------------------------------------

Github user chinmaykolhatkar commented on a diff in the pull request:

    https://github.com/apache/apex-malhar/pull/298#discussion_r66694101
  
    --- Diff: kafka/src/main/java/org/apache/apex/malhar/kafka/AbstractExactlyOnceKafkaOutputOperator.java ---
    @@ -0,0 +1,366 @@
    +/**
    + * 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.apex.malhar.kafka;
    +
    +import java.io.IOException;
    +import java.util.ArrayList;
    +import java.util.HashMap;
    +import java.util.List;
    +import java.util.Map;
    +import java.util.Properties;
    +import java.util.concurrent.ExecutionException;
    +
    +import org.slf4j.Logger;
    +import org.slf4j.LoggerFactory;
    +
    +import org.apache.apex.malhar.lib.wal.FSWindowDataManager;
    +import org.apache.apex.malhar.lib.wal.WindowDataManager;
    +
    +import org.apache.kafka.clients.consumer.ConsumerRecord;
    +import org.apache.kafka.clients.consumer.ConsumerRecords;
    +import org.apache.kafka.clients.consumer.KafkaConsumer;
    +import org.apache.kafka.clients.producer.ProducerRecord;
    +import org.apache.kafka.common.PartitionInfo;
    +import org.apache.kafka.common.TopicPartition;
    +
    +import com.datatorrent.api.Context;
    +import com.datatorrent.api.Operator;
    +
    +import static org.apache.kafka.clients.consumer.ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG;
    +import static org.apache.kafka.clients.consumer.ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG;
    +import static org.apache.kafka.clients.consumer.ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG;
    +import static org.apache.kafka.clients.producer.ProducerConfig.ACKS_CONFIG;
    +
    +/**
    + * Kafka output operator with exactly once processing semantics under certain conditions.,
    + *
    + *  Requirement for Exactly Once:
    + *   Every message within the Window is unique
    + *
    + *  This operator uses *Key* to distinguish the messages written by particular instance of the Output operator.
    + *  Operator users can only use *value* for storing the data.
    + *
    + * @displayName Abstract Exactly Once Kafka Output(0.9.0)
    + * @category Messaging
    + * @tags output operator
    + *
    + * @since 3.5
    + */
    +@org.apache.hadoop.classification.InterfaceStability.Evolving
    +public abstract class AbstractExactlyOnceKafkaOutputOperator<T> extends AbstractKafkaOutputOperator<String, T>
    +    implements Operator.CheckpointNotificationListener
    --- End diff --
    
    I see this class is extended by KafkaSinglePortExactlyOnceOutputOperator.. The subclass does following 2 things:
    1. Add a port
    2. call sendTuple method of parent class.
    
    I see there is no need to have this one as abstract operator. This can become concreate and add the port here itself


> Kafka Output Operator with Kafka 0.9 API
> ----------------------------------------
>
>                 Key: APEXMALHAR-2086
>                 URL: https://issues.apache.org/jira/browse/APEXMALHAR-2086
>             Project: Apache Apex Malhar
>          Issue Type: New Feature
>            Reporter: Sandesh
>            Assignee: Sandesh
>
> Goal : 2 Operartors for Kafka Output
>       1. Simple Kafka Output Operator 
>             - Supports Atleast Once 
>             - Expose most used producer properties as class properties
>       2. Exactly Once Kafka Output ( Not possible in all the cases, will be documented later )
>             
> Design for Exactly Once
> Window Data Manager - Stores the Kafka partitions offsets.
> Kafka Key - Used by the operator = AppID#OperatorId
> During recovery. Partially written window is re-created using the following  approach:
> Tuples between the largest recovery offsets and the current offset are checked. Based on the key, tuples written by the other entities are discarded. 
> Only tuples which are not in the recovered set are emitted.
> Tuples needs to be unique within the window.
>       


--
This message was sent by Atlassian JIRA
(v6.3.4#6332)