301 lines
9.5 KiB
HTML
301 lines
9.5 KiB
HTML
<!DOCTYPE html>
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<meta name="author" content="Yann Esposito">
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<title>Druid pour l’analyse de données en temps réel</title>
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<link rel="stylesheet" href="../styling.css">
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</head>
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<body>
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<header>
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<h1 class="title">Druid pour l’analyse de données en temps réel</h1>
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<h2 class="author">Yann Esposito</h2>
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<h3 class="date">7 Avril 2016</h3>
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</header>
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<nav id="TOC">
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<ul>
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<li><a href="#intro">Intro</a><ul>
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<li><a href="#plan">Plan</a></li>
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<li><a href="#experience">Experience</a></li>
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<li><a href="#real-time">Real Time?</a></li>
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<li><a href="#demande">Demande</a></li>
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<li><a href="#en-pratique">En pratique</a></li>
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<li><a href="#origine-php">Origine (PHP)</a></li>
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<li><a href="#introduction">Introduction</a></li>
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<li><a href="#pre-considerations">Pre Considerations</a></li>
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<li><a href="#try-to-conceptualize-events">Try to conceptualize (events)</a></li>
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<li><a href="#in-the-end">In the End</a></li>
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</ul></li>
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<li><a href="#druid">Druid</a><ul>
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<li><a href="#who">Who</a></li>
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<li><a href="#goal">Goal</a></li>
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<li><a href="#concepts">Concepts</a></li>
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<li><a href="#features">Features</a></li>
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<li><a href="#storage">Storage</a></li>
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<li><a href="#columnar-storage">Columnar Storage</a></li>
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<li><a href="#index">Index</a></li>
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<li><a href="#data-segments">Data Segments</a></li>
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<li><a href="#real-time-ingestion">Real-time ingestion</a></li>
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<li><a href="#batch-ingestion">Batch Ingestion</a></li>
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<li><a href="#real-time-ingestion-1">Real-time Ingestion</a></li>
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</ul></li>
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<li><a href="#querying">Querying</a><ul>
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<li><a href="#query-types">Query types</a></li>
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<li><a href="#tip">Tip</a></li>
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<li><a href="#query-spec">Query Spec</a></li>
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<li><a href="#examples">Example(s)</a></li>
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<li><a href="#caching">Caching</a></li>
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<li><a href="#load-rules">Load Rules</a></li>
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</ul></li>
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<li><a href="#components">Components</a><ul>
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<li><a href="#druid-components">Druid Components</a></li>
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<li><a href="#coordinator">Coordinator</a></li>
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<li><a href="#real-time-nodes">Real-time Nodes</a></li>
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<li><a href="#historical-nodes">Historical Nodes</a></li>
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<li><a href="#overlord">Overlord</a></li>
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<li><a href="#middle-manager">Middle Manager</a></li>
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<li><a href="#broker-nodes">Broker Nodes</a></li>
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<li><a href="#deep-storage">Deep Storage</a></li>
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</ul></li>
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<li><a href="#considerations-tools">Considerations & Tools</a><ul>
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<li><a href="#when-not-to-choose-druid">When <em>not</em> to choose Druid</a></li>
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<li><a href="#graphite-metrics">Graphite (metrics)</a></li>
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<li><a href="#pivot-exploring-data">Pivot (exploring data)</a></li>
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<li><a href="#caravel-exploring-data">Caravel (exploring data)</a></li>
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</ul></li>
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</ul>
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</nav>
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<h1 id="intro">Intro</h1>
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<h2 id="plan">Plan</h2>
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<ul>
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<li>Introduction; why?</li>
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<li>How?</li>
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</ul>
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<h2 id="experience">Experience</h2>
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<ul>
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<li>Real Time Social Media Analytics</li>
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</ul>
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<h2 id="real-time">Real Time?</h2>
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<ul>
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<li>Ingestion Latency: seconds</li>
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<li>Query Latency: seconds</li>
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</ul>
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<h2 id="demande">Demande</h2>
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<ul>
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<li>Twitter: <code>20k msg/s</code>, <code>1msg = 10ko</code> pendant 24h</li>
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<li>Facebook public: 1000 à 2000 msg/s en continu</li>
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</ul>
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<h2 id="en-pratique">En pratique</h2>
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<ul>
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<li>Twitter: 400 msg/s en continu, pics à 1500</li>
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</ul>
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<h2 id="origine-php">Origine (PHP)</h2>
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<p><img src="img/bad_php.jpg" alt="History" /> </p>
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<h2 id="introduction">Introduction</h2>
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<ul>
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<li>Traitement de donnée gros volume + faible latence</li>
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<li>Typiquement <code>pulse</code></li>
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</ul>
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<p><a href="http://pulse.vigiglo.be/#/vigiglobe/Earthquake/dashboard" target="_blank"> DEMO </a></p>
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<h2 id="pre-considerations">Pre Considerations</h2>
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<p>Discovered vs Invented</p>
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<h2 id="try-to-conceptualize-events">Try to conceptualize (events)</h2>
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<p>Scalable + Real Time + Fail safe</p>
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<ul>
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<li>timeseries</li>
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<li>alerting system</li>
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<li>top N</li>
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<li>etc…</li>
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</ul>
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<h2 id="in-the-end">In the End</h2>
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<p>Druid concepts are always emerging naturally</p>
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<h1 id="druid">Druid</h1>
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<h2 id="who">Who</h2>
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<p>Metamarkets</p>
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<h2 id="goal">Goal</h2>
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<blockquote>
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<p>Druid is an open source store designed for real-time exploratory analytics on large data sets.</p>
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</blockquote>
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<blockquote>
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<p>hosted dashboard that would allow users to arbitrarily explore and visualize event streams.</p>
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</blockquote>
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<h2 id="concepts">Concepts</h2>
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<ul>
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<li>Column-oriented storage layout</li>
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<li>distributed, shared-nothing architecture</li>
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<li>advanced indexing structure</li>
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</ul>
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<h2 id="features">Features</h2>
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<ul>
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<li>fast aggregations</li>
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<li>flexible filters</li>
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<li>low latency data ingestion</li>
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</ul>
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<p><strong>arbitrary exploration of billion-row tables tables with sub-second latencies</strong></p>
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<h2 id="storage">Storage</h2>
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<ul>
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<li>Columnar</li>
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<li>Inverted Index</li>
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<li>Immutable Segments</li>
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</ul>
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<h2 id="columnar-storage">Columnar Storage</h2>
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<h2 id="index">Index</h2>
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<ul>
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<li>Values are dictionary encoded</li>
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</ul>
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<p><code>{"USA" 1, "Canada" 2, "Mexico" 3, ...}</code></p>
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<ul>
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<li>Bitmap for every dimension value (used by filters)</li>
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</ul>
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<p><code>"USA" -> [0 1 0 0 1 1 0 0 0]</code></p>
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<ul>
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<li>Column values (used by aggergation queries)</li>
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</ul>
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<p><code>[2,1,3,15,1,1,2,8,7]</code></p>
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<h2 id="data-segments">Data Segments</h2>
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<ul>
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<li>Per time interval</li>
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<li>skip segments when querying</li>
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<li>Immutable</li>
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<li>Cache friendly</li>
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<li>No locking</li>
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<li>Versioned</li>
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<li>No locking</li>
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<li>Read-write concurrency</li>
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</ul>
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<h2 id="real-time-ingestion">Real-time ingestion</h2>
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<ul>
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<li>Via Real-Time Node and Firehose</li>
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<li>No redundancy or HA, thus not recommended</li>
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<li>Via Indexing Service and Tranquility API</li>
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<li>Core API</li>
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<li>Integration with Streaming Frameworks</li>
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<li>HTTP Server</li>
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<li><strong>Kafka Consumer</strong></li>
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</ul>
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<h2 id="batch-ingestion">Batch Ingestion</h2>
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<ul>
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<li>File based (HDFS, S3, …)</li>
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</ul>
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<h2 id="real-time-ingestion-1">Real-time Ingestion</h2>
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<pre><code>Task 1: [ Interval ][ Window ]
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Task 2: [ ]
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--------------------------------------->
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time</code></pre>
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<p>Minimum indexing slots =<br />
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Data Sources × Partitions × Replicas × 2</p>
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<h1 id="querying">Querying</h1>
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<h2 id="query-types">Query types</h2>
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<ul>
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<li>Group by: group by multiple dimensions</li>
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<li>Top N: like grouping by a single dimension</li>
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<li>Timeseries: without grouping over dimensions</li>
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<li>Search: Dimensions lookup</li>
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<li>Time Boundary: Find available data timeframe</li>
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<li>Metadata queries</li>
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</ul>
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<h2 id="tip">Tip</h2>
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<ul>
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<li>Prefer <code>topN</code> over <code>groupBy</code></li>
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<li>Prefer <code>timeseries</code> over <code>topN</code></li>
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<li>Use limits (and priorities)</li>
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</ul>
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<h2 id="query-spec">Query Spec</h2>
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<ul>
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<li>Data source</li>
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<li>Dimensions</li>
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<li>Interval</li>
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<li>Filters</li>
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<li>Aggergations</li>
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<li>Post Aggregations</li>
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<li>Granularity</li>
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<li>Context (query configuration)</li>
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<li>Limit</li>
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</ul>
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<h2 id="examples">Example(s)</h2>
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<p>TODO</p>
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<h2 id="caching">Caching</h2>
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<ul>
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<li>Historical node level</li>
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<li>By segment</li>
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<li>Broker Level</li>
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<li>By segment and query</li>
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<li><code>groupBy</code> is disabled on purpose!</li>
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<li>By default - local caching</li>
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</ul>
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<h2 id="load-rules">Load Rules</h2>
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<ul>
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<li>Can be defined</li>
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<li>What can be set</li>
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</ul>
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<h1 id="components">Components</h1>
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<h2 id="druid-components">Druid Components</h2>
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<ul>
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<li>Real-time Nodes</li>
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<li>Historical Nodes</li>
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<li>Broker Nodes</li>
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<li>Coordinator</li>
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<li>For indexing:</li>
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<li>Overlord</li>
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<li><p>Middle Manager</p></li>
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<li>Deep Storage</li>
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<li><p>Metadata Storage</p></li>
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<li>Load Balancer</li>
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<li><p>Cache</p></li>
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</ul>
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<h2 id="coordinator">Coordinator</h2>
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<p>Manage Segments</p>
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<h2 id="real-time-nodes">Real-time Nodes</h2>
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<ul>
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<li>Pulling data in real-time</li>
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<li>Indexing it</li>
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</ul>
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<h2 id="historical-nodes">Historical Nodes</h2>
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<ul>
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<li>Keep historical segments</li>
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</ul>
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<h2 id="overlord">Overlord</h2>
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<ul>
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<li>Accepts tasks and distributes them to middle manager</li>
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</ul>
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<h2 id="middle-manager">Middle Manager</h2>
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<ul>
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<li>Execute submitted tasks via Peons</li>
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</ul>
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<h2 id="broker-nodes">Broker Nodes</h2>
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<ul>
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<li>Route query to Real-time and Historical nodes</li>
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<li>Merge results</li>
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</ul>
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<h2 id="deep-storage">Deep Storage</h2>
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<ul>
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<li>Segments backup (HDFS, S3, …)</li>
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</ul>
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<h1 id="considerations-tools">Considerations & Tools</h1>
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<h2 id="when-not-to-choose-druid">When <em>not</em> to choose Druid</h2>
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<ul>
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<li>Data is not time-series</li>
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<li>Cardinality is <em>very</em> high</li>
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<li>Number of dimensions is high</li>
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<li>Setup cost must be avoided</li>
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</ul>
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<h2 id="graphite-metrics">Graphite (metrics)</h2>
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<p><img src="img/graphite.png" alt="Graphite" />__</p>
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<p><a href="http://graphite.wikidot.com">Graphite</a></p>
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<h2 id="pivot-exploring-data">Pivot (exploring data)</h2>
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<p><img src="img/pivot.gif" alt="Pivot" /> </p>
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<p><a href="https://github.com/implydata/pivot">Pivot</a></p>
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<h2 id="caravel-exploring-data">Caravel (exploring data)</h2>
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<p><img src="img/caravel.png" alt="caravel" /> </p>
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<p><a href="https://github.com/airbnb/caravel">Caravel</a></p>
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<div id="footer">
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<a href="yannesposito.com">Y</a>
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</div>
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</body>
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</html>
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