<?xml version="1.0" encoding="UTF-8"?>
<!--
 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.
-->
<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" contentScriptType="application/ecmascript" contentStyleType="text/css" height="538px" preserveAspectRatio="none" style="width:574px;height:538px;" version="1.1" viewBox="0 0 574 538" width="574px" zoomAndPan="magnify"><defs/><g><rect fill="#6B9FE6" height="435.2813" style="stroke: #6B9FE6; stroke-width: 1.0;" width="10" x="250.5" y="82.0469"/><rect fill="#6B9FE6" height="152.1719" style="stroke: #6B9FE6; stroke-width: 1.0;" width="10" x="367.5" y="356.1563"/><rect fill="#6B9FE6" height="338.5781" style="stroke: #6B9FE6; stroke-width: 1.0;" width="10" x="468.5" y="140.5156"/><line style="stroke: #6B9FE6; stroke-width: 1.0; stroke-dasharray: 5.0,5.0;" x1="37" x2="37" y1="50.8125" y2="526.3281"/><line style="stroke: #6B9FE6; stroke-width: 1.0; stroke-dasharray: 5.0,5.0;" x1="255.5" x2="255.5" y1="50.8125" y2="526.3281"/><line style="stroke: #6B9FE6; stroke-width: 1.0; stroke-dasharray: 5.0,5.0;" x1="372.5" x2="372.5" y1="50.8125" y2="526.3281"/><line style="stroke: #6B9FE6; stroke-width: 1.0; stroke-dasharray: 5.0,5.0;" x1="473.5" x2="473.5" y1="50.8125" y2="526.3281"/><rect fill="#8AC483" height="30.4063" style="stroke: #8AC483; stroke-width: 1.5;" width="59" x="8" y="19.4063"/><text fill="#000000" font-family="Roboto" font-size="14" lengthAdjust="spacingAndGlyphs" textLength="45" x="15" y="39.3945">Runner</text><rect fill="#8AC483" height="46.8125" style="stroke: #8AC483; stroke-width: 1.5;" width="94" x="208.5" y="3"/><text fill="#000000" font-family="Roboto" font-size="14" font-style="italic" lengthAdjust="spacingAndGlyphs" textLength="80" x="215.5" y="24">«Serializable»</text><text fill="#000000" font-family="Roboto" font-size="14" lengthAdjust="spacingAndGlyphs" textLength="43" x="234" y="40.4063">Source</text><rect fill="#8AC483" height="30.4063" style="stroke: #8AC483; stroke-width: 1.5;" width="58" x="343.5" y="19.4063"/><text fill="#000000" font-family="Roboto" font-size="14" lengthAdjust="spacingAndGlyphs" textLength="44" x="350.5" y="39.3945">Reader</text><rect fill="#8AC483" height="30.4063" style="stroke: #8AC483; stroke-width: 1.5;" width="86" x="430.5" y="19.4063"/><text fill="#000000" font-family="Roboto" font-size="14" lengthAdjust="spacingAndGlyphs" textLength="72" x="437.5" y="39.3945">Middleware</text><rect fill="#6B9FE6" height="435.2813" style="stroke: #6B9FE6; stroke-width: 1.0;" width="10" x="250.5" y="82.0469"/><rect fill="#6B9FE6" height="152.1719" style="stroke: #6B9FE6; stroke-width: 1.0;" width="10" x="367.5" y="356.1563"/><rect fill="#6B9FE6" height="338.5781" style="stroke: #6B9FE6; stroke-width: 1.0;" width="10" x="468.5" y="140.5156"/><polygon fill="#67666A" points="238.5,78.0469,248.5,82.0469,238.5,86.0469,242.5,82.0469" style="stroke: #67666A; stroke-width: 1.0;"/><line style="stroke: #67666A; stroke-width: 2.0;" x1="37.5" x2="244.5" y1="82.0469" y2="82.0469"/><text fill="#000000" font-family="Roboto" font-size="13" font-weight="bold" lengthAdjust="spacingAndGlyphs" textLength="80" x="44.5" y="76.873">create source</text><polygon fill="#67666A" points="238.5,107.2813,248.5,111.2813,238.5,115.2813,242.5,111.2813" style="stroke: #67666A; stroke-width: 1.0;"/><line style="stroke: #67666A; stroke-width: 2.0;" x1="37.5" x2="244.5" y1="111.2813" y2="111.2813"/><text fill="#000000" font-family="Roboto" font-size="13" lengthAdjust="spacingAndGlyphs" textLength="104" x="44.5" y="106.1074">get estimated size</text><polygon fill="#67666A" points="456.5,136.5156,466.5,140.5156,456.5,144.5156,460.5,140.5156" style="stroke: #67666A; stroke-width: 1.0;"/><line style="stroke: #67666A; stroke-width: 2.0;" x1="260.5" x2="462.5" y1="140.5156" y2="140.5156"/><text fill="#000000" font-family="Roboto" font-size="13" font-weight="bold" lengthAdjust="spacingAndGlyphs" textLength="77" x="267.5" y="135.3418">estimate size</text><polygon fill="#67666A" points="48.5,165.75,38.5,169.75,48.5,173.75,44.5,169.75" style="stroke: #67666A; stroke-width: 1.0;"/><line style="stroke: #67666A; stroke-width: 2.0; stroke-dasharray: 2.0,2.0;" x1="42.5" x2="249.5" y1="169.75" y2="169.75"/><text fill="#000000" font-family="Roboto" font-size="13" lengthAdjust="spacingAndGlyphs" textLength="66" x="54.5" y="164.5762">size of data</text><line style="stroke: #67666A; stroke-width: 2.0;" x1="37.5" x2="79.5" y1="214.2188" y2="214.2188"/><line style="stroke: #67666A; stroke-width: 2.0;" x1="79.5" x2="79.5" y1="214.2188" y2="227.2188"/><line style="stroke: #67666A; stroke-width: 2.0;" x1="38.5" x2="79.5" y1="227.2188" y2="227.2188"/><polygon fill="#67666A" points="48.5,223.2188,38.5,227.2188,48.5,231.2188,44.5,227.2188" style="stroke: #67666A; stroke-width: 1.0;"/><text fill="#000000" font-family="Roboto" font-size="13" lengthAdjust="spacingAndGlyphs" textLength="204" x="44.5" y="193.8105">compute size / number of executors</text><text fill="#000000" font-family="Roboto" font-size="13" lengthAdjust="spacingAndGlyphs" textLength="119" x="47.5" y="209.0449">= desired bundle size</text><polygon fill="#67666A" points="238.5,255.4531,248.5,259.4531,238.5,263.4531,242.5,259.4531" style="stroke: #67666A; stroke-width: 1.0;"/><line style="stroke: #67666A; stroke-width: 2.0;" x1="37.5" x2="244.5" y1="259.4531" y2="259.4531"/><text fill="#000000" font-family="Roboto" font-size="13" lengthAdjust="spacingAndGlyphs" textLength="187" x="44.5" y="254.2793">split source (desired bundle size)</text><path d="M265,240.2188 L265,265.2188 L548,265.2188 L548,250.2188 L538,240.2188 L265,240.2188 " fill="#CEE2F2" style="stroke: #CEE2F2; stroke-width: 1.0;"/><path d="M538,240.2188 L538,250.2188 L548,250.2188 L538,240.2188 " fill="#CEE2F2" style="stroke: #CEE2F2; stroke-width: 1.0;"/><text fill="#000000" font-family="Roboto" font-size="13" lengthAdjust="spacingAndGlyphs" textLength="262" x="271" y="257.2793">streaming: split based on number of executors</text><polygon fill="#67666A" points="48.5,290.6875,38.5,294.6875,48.5,298.6875,44.5,294.6875" style="stroke: #67666A; stroke-width: 1.0;"/><line style="stroke: #67666A; stroke-width: 2.0; stroke-dasharray: 2.0,2.0;" x1="42.5" x2="249.5" y1="294.6875" y2="294.6875"/><text fill="#000000" font-family="Roboto" font-size="13" lengthAdjust="spacingAndGlyphs" textLength="70" x="54.5" y="289.5137">list&lt;source&gt;</text><path d="M265,275.4531 L265,300.4531 L562,300.4531 L562,285.4531 L552,275.4531 L265,275.4531 " fill="#CEE2F2" style="stroke: #CEE2F2; stroke-width: 1.0;"/><path d="M552,275.4531 L552,285.4531 L562,285.4531 L552,275.4531 " fill="#CEE2F2" style="stroke: #CEE2F2; stroke-width: 1.0;"/><text fill="#000000" font-family="Roboto" font-size="13" lengthAdjust="spacingAndGlyphs" textLength="276" x="271" y="292.5137">streaming: runner asks the source for watermark</text><polygon fill="#67666A" points="238.5,322.9219,248.5,326.9219,238.5,330.9219,242.5,326.9219" style="stroke: #67666A; stroke-width: 1.0;"/><line style="stroke: #67666A; stroke-width: 2.0;" x1="37.5" x2="244.5" y1="326.9219" y2="326.9219"/><text fill="#000000" font-family="Roboto" font-size="13" font-weight="bold" lengthAdjust="spacingAndGlyphs" textLength="182" x="44.5" y="321.748">for each source create a reader</text><polygon fill="#67666A" points="355.5,352.1563,365.5,356.1563,355.5,360.1563,359.5,356.1563" style="stroke: #67666A; stroke-width: 1.0;"/><line style="stroke: #67666A; stroke-width: 2.0;" x1="260.5" x2="361.5" y1="356.1563" y2="356.1563"/><text fill="#000000" font-family="Roboto" font-size="13" font-weight="bold" lengthAdjust="spacingAndGlyphs" textLength="88" x="267.5" y="350.9824">create a reader</text><polygon fill="#67666A" points="48.5,384.3906,38.5,388.3906,48.5,392.3906,44.5,388.3906" style="stroke: #67666A; stroke-width: 1.0;"/><line style="stroke: #67666A; stroke-width: 2.0; stroke-dasharray: 2.0,2.0;" x1="42.5" x2="366.5" y1="388.3906" y2="388.3906"/><text fill="#000000" font-family="Roboto" font-size="13" font-weight="bold" lengthAdjust="spacingAndGlyphs" textLength="45" x="54.5" y="383.2168">readers</text><path d="M382,369.1563 L382,394.1563 L539,394.1563 L539,379.1563 L529,369.1563 L382,369.1563 " fill="#CEE2F2" style="stroke: #CEE2F2; stroke-width: 1.0;"/><path d="M529,369.1563 L529,379.1563 L539,379.1563 L529,369.1563 " fill="#CEE2F2" style="stroke: #CEE2F2; stroke-width: 1.0;"/><text fill="#000000" font-family="Roboto" font-size="13" lengthAdjust="spacingAndGlyphs" textLength="136" x="388" y="386.2168">streaming: + checkpoint</text><polygon fill="#67666A" points="355.5,416.625,365.5,420.625,355.5,424.625,359.5,420.625" style="stroke: #67666A; stroke-width: 1.0;"/><line style="stroke: #67666A; stroke-width: 2.0;" x1="37.5" x2="361.5" y1="420.625" y2="420.625"/><text fill="#000000" font-family="Roboto" font-size="13" font-weight="bold" lengthAdjust="spacingAndGlyphs" textLength="167" x="44.5" y="415.4512">for each reader : start reader</text><polygon fill="#67666A" points="355.5,445.8594,365.5,449.8594,355.5,453.8594,359.5,449.8594" style="stroke: #67666A; stroke-width: 1.0;"/><line style="stroke: #67666A; stroke-width: 2.0;" x1="37.5" x2="361.5" y1="449.8594" y2="449.8594"/><text fill="#000000" font-family="Roboto" font-size="13" font-weight="bold" lengthAdjust="spacingAndGlyphs" textLength="183" x="44.5" y="444.6855">read elements until none to read</text><polygon fill="#67666A" points="461.5,475.0938,471.5,479.0938,461.5,483.0938,465.5,479.0938" style="stroke: #67666A; stroke-width: 1.0;"/><line style="stroke: #67666A; stroke-width: 2.0;" x1="377.5" x2="467.5" y1="479.0938" y2="479.0938"/><text fill="#000000" font-family="Roboto" font-size="13" font-weight="bold" lengthAdjust="spacingAndGlyphs" textLength="67" x="384.5" y="473.9199">get element</text><polygon fill="#67666A" points="360.5,504.3281,370.5,508.3281,360.5,512.3281,364.5,508.3281" style="stroke: #67666A; stroke-width: 1.0;"/><line style="stroke: #67666A; stroke-width: 2.0;" x1="37.5" x2="366.5" y1="508.3281" y2="508.3281"/><text fill="#000000" font-family="Roboto" font-size="13" font-weight="bold" lengthAdjust="spacingAndGlyphs" textLength="72" x="44.5" y="503.1543">close reader</text><!--MD5=[6e6ef42902efdf0e23898c2d72194b90]
@startuml

hide footbox
skinparam backgroundColor transparent
skinparam shadowing false
skinparam defaultFontName "Roboto"

skinparam sequenceArrowThickness 2

skinparam note {
  BackgroundColor #cee2f2
  BorderColor #cee2f2
}

skinparam sequence {
  ArrowColor #67666a

  LifeLineBorderColor #6b9fe6
  LifeLineBackgroundColor #6b9fe6

  GroupBackgroundColor #8ac483
  GroupBorderColor #8ac483

  ParticipantBackgroundColor #8ac483
  ParticipantBorderColor #8ac483
}

participant Runner
participant "Source" << Serializable >>
participant "Reader"
participant Middleware

Runner -> Source: **create source**
activate Source

Runner -> Source: get estimated size

Source -> Middleware: **estimate size**
activate Middleware

Source - -> Runner: size of data

Runner -> Runner: compute size / number of executors\n = desired bundle size

Runner -> Source: split source (desired bundle size)
note right
  streaming: split based on number of executors
end note

Source - -> Runner: list<source>
note right
  streaming: runner asks the source for watermark
end note

Runner -> Source: **for each source create a reader**

Source -> Reader: **create a reader**
activate Reader

Reader - -> Runner: **readers**
note right
  streaming: + checkpoint
end note

Runner -> Reader: **for each reader : start reader**

Runner -> Reader: **read elements until none to read**

Reader -> Middleware: **get element**

deactivate Middleware

Runner -> Reader: **close reader**
deactivate Reader
@enduml

PlantUML version 1.2019.11(Sun Sep 22 12:02:15 CEST 2019)
(GPL source distribution)
Java Runtime: OpenJDK Runtime Environment
JVM: OpenJDK 64-Bit Server VM
Java Version: 1.8.0_222-b10
Operating System: Linux
Default Encoding: UTF-8
Language: en
Country: CA
--></g></svg>