[jira] [Commented] (APEXMALHAR-2085) Implement Windowed Operators

["ASF GitHub Bot (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/APEXMALHAR-2085?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15359095#comment-15359095 ] 

ASF GitHub Bot commented on APEXMALHAR-2085:
--------------------------------------------

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

    https://github.com/apache/apex-malhar/pull/319#discussion_r69312802
  
    --- Diff: library/src/main/java/org/apache/apex/malhar/lib/window/WindowedStorage.java ---
    @@ -0,0 +1,88 @@
    +/**
    + * 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.lib.window;
    +
    +import java.util.Map;
    +
    +import org.apache.hadoop.classification.InterfaceStability;
    +
    +/**
    + * WindowedStorage is a key-value store with the key being the window. The implementation of this interface should
    + * make sure checkpointing and recovery will be done correctly.
    + *
    + * @param <T> The type of the data that is stored per window
    + *
    + * TODO: Look at the possibility of integrating spillable data structure: https://issues.apache.org/jira/browse/APEXMALHAR-2026
    --- End diff --
    
    This seems very similar to the managed state implementations. Can we also look at managed state directly before looking at Spillable data structures? 


> Implement Windowed Operators
> ----------------------------
>
>                 Key: APEXMALHAR-2085
>                 URL: https://issues.apache.org/jira/browse/APEXMALHAR-2085
>             Project: Apache Apex Malhar
>          Issue Type: New Feature
>            Reporter: Siyuan Hua
>            Assignee: David Yan
>
> As per our recent several discussions in the community. A group of Windowed Operators that delivers the window semantic follows the google Data Flow model(https://cloud.google.com/dataflow/) is very important. 
> The operators should be designed and implemented in a way for 
> High-level API
> Beam translation
> Easy to use with other popular operator
> {panel:title=Operator Hierarchy}
> Hierarchy of the operators,
> The windowed operators should cover all possible transformations that require window, and batch processing is also considered as special window called global window
> {code}
>                    +-------------------+
>        +---------> |  WindowedOperator | <--------+
>        |           +--------+----------+          |
>        |                    ^      ^--------------------------------+
>        |                    |                     |                 |
>        |                    |                     |                 |
> +------+--------+    +------+------+      +-------+-----+    +------+-----+
> |CombineOperator|    |GroupOperator|      |KeyedOperator|    |JoinOperator|
> +---------------+    +-------------+      +------+------+    +-----+------+
>                                    +---------^   ^                 ^
>                                    |             |                 |
>                           +--------+---+   +-----+----+       +----+----+
>                           |KeyedCombine|   |KeyedGroup|       | CoGroup |
>                           +------------+   +----------+       +---------+
> {code}
> Combine operation includes all operations that combine all tuples in one window into one or small number of tuples, Group operation group all tuples in one window, Join and CoGroup are used to join and group tuples from different inputs.
> {panel}
> {panel:title=Components}
> * Window Component
> It includes configuration, window state that should be checkpointed, etc. It should support NonMergibleWindow(fixed or slide) MergibleWindow(Session)
> * Trigger
> It should support early trigger, late trigger with customizable trigger behaviour 
> * Other related components:
> ** Watermark generator, can be plugged into input source to generate watermark
> ** Tuple schema support:
> It should handle either predefined tuple type or give a declarative API to describe the user defined tuple class
> {panel}
> Most component API should be reused in High-Level API
> This is the umbrella ticket, separate tickets would be created for different components and operators respectively 



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