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href="/docs/0.16.1-incubating/comparisons/druid-vs-key-value.html">Apache Druid vs. Key/Value Stores (HBase/Cassandra/OpenTSDB)</a></li><li class="navListItem"><a class="navItem" href="/docs/0.16.1-incubating/comparisons/druid-vs-kudu.html">Apache Druid vs Kudu</a></li><li class="navListItem"><a class="navItem" href="/docs/0.16.1-incubating/comparisons/druid-vs-redshift.html">Apache Druid vs Redshift</a></li><li class="navListItem"><a class="navItem" href="/docs/0.16.1-incubating/comparisons/druid-vs-spark.html">Apache Druid vs Spark</a></li><li class="navListItem"><a class="navItem" href="/docs/0.16.1-incubating/comparisons/druid-vs-sql-on-hadoop.html">Apache Druid vs SQL-on-Hadoop</a></li><li class="navListItem"><a class="navItem" href="/docs/0.16.1-incubating/design/auth.html">Authentication and Authorization</a></li><li class="navListItem"><a class="navItem" href="/docs/0.16.1-incubating/design/broker.html">Broker</a></li><li class="navListItem"><a class="navItem" 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</script></nav></div><div class="container mainContainer"><div class="wrapper"><div class="post"><header class="postHeader"><a class="edit-page-link button" href="https://github.com/apache/incubator-druid/edit/master/docs/development/extensions-core/protobuf.md" target="_blank" rel="noreferrer noopener">Edit</a><h1 class="postHeaderTitle">Protobuf</h1></header><article><div><span><!--
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<p>This Apache Druid (incubating) extension enables Druid to ingest and understand the Protobuf data format. Make sure to <a href="/docs/0.16.1-incubating/development/extensions.html#loading-extensions">include</a> <code>druid-protobuf-extensions</code> as an extension.</p>
<h2><a class="anchor" aria-hidden="true" id="protobuf-parser"></a><a href="#protobuf-parser" aria-hidden="true" class="hash-link"><svg class="hash-link-icon" aria-hidden="true" height="16" version="1.1" viewBox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"></path></svg></a>Protobuf Parser</h2>
<table>
<thead>
<tr><th>Field</th><th>Type</th><th>Description</th><th>Required</th></tr>
</thead>
<tbody>
<tr><td>type</td><td>String</td><td>This should say <code>protobuf</code>.</td><td>no</td></tr>
<tr><td>descriptor</td><td>String</td><td>Protobuf descriptor file name in the classpath or URL.</td><td>yes</td></tr>
<tr><td>protoMessageType</td><td>String</td><td>Protobuf message type in the descriptor. Both short name and fully qualified name are accepted. The parser uses the first message type found in the descriptor if not specified.</td><td>no</td></tr>
<tr><td>parseSpec</td><td>JSON Object</td><td>Specifies the timestamp and dimensions of the data. The format must be JSON. See <a href="/docs/0.16.1-incubating/ingestion/index.html">JSON ParseSpec</a> for more configuration options. Please note timeAndDims parseSpec is no longer supported.</td><td>yes</td></tr>
</tbody>
</table>
<h2><a class="anchor" aria-hidden="true" id="example-load-protobuf-messages-from-kafka"></a><a href="#example-load-protobuf-messages-from-kafka" aria-hidden="true" class="hash-link"><svg class="hash-link-icon" aria-hidden="true" height="16" version="1.1" viewBox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"></path></svg></a>Example: Load Protobuf messages from Kafka</h2>
<p>This example demonstrates how to load Protobuf messages from Kafka. Please read the <a href="/docs/0.16.1-incubating/tutorials/tutorial-kafka.html">Load from Kafka tutorial</a> first. This example will use the same &quot;metrics&quot; dataset.</p>
<p>Files used in this example are found at <code>./examples/quickstart/protobuf</code> in your Druid directory.</p>
<ul>
<li>We will use <a href="/docs/0.16.1-incubating/development/extensions-core/kafka-ingestion.html">Kafka Indexing Service</a> instead of Tranquility.</li>
<li>Kafka broker host is <code>localhost:9092</code>.</li>
<li>Kafka topic is <code>metrics_pb</code> instead of <code>metrics</code>.</li>
<li>datasource name is <code>metrics-kafka-pb</code> instead of <code>metrics-kafka</code> to avoid the confusion.</li>
</ul>
<p>Here is the metrics JSON example.</p>
<pre><code class="hljs css language-json">{
<span class="hljs-attr">"unit"</span>: <span class="hljs-string">"milliseconds"</span>,
<span class="hljs-attr">"http_method"</span>: <span class="hljs-string">"GET"</span>,
<span class="hljs-attr">"value"</span>: <span class="hljs-number">44</span>,
<span class="hljs-attr">"timestamp"</span>: <span class="hljs-string">"2017-04-06T02:36:22Z"</span>,
<span class="hljs-attr">"http_code"</span>: <span class="hljs-string">"200"</span>,
<span class="hljs-attr">"page"</span>: <span class="hljs-string">"/"</span>,
<span class="hljs-attr">"metricType"</span>: <span class="hljs-string">"request/latency"</span>,
<span class="hljs-attr">"server"</span>: <span class="hljs-string">"www1.example.com"</span>
}
</code></pre>
<h3><a class="anchor" aria-hidden="true" id="proto-file"></a><a href="#proto-file" aria-hidden="true" class="hash-link"><svg class="hash-link-icon" aria-hidden="true" height="16" version="1.1" viewBox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"></path></svg></a>Proto file</h3>
<p>The proto file should look like this. Save it as metrics.proto.</p>
<pre><code class="hljs">syntax = <span class="hljs-string">"proto3"</span>;
message Metrics {
string unit = 1;
string http_method = 2;
int32 value = 3;
string timestamp = 4;
string http_code = 5;
string<span class="hljs-built_in"> page </span>= 6;
string metricType = 7;
string<span class="hljs-built_in"> server </span>= 8;
}
</code></pre>
<h3><a class="anchor" aria-hidden="true" id="descriptor-file"></a><a href="#descriptor-file" aria-hidden="true" class="hash-link"><svg class="hash-link-icon" aria-hidden="true" height="16" version="1.1" viewBox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"></path></svg></a>Descriptor file</h3>
<p>Using the <code>protoc</code> Protobuf compiler to generate the descriptor file. Save the metrics.desc file either in the classpath or reachable by URL. In this example the descriptor file was saved at /tmp/metrics.desc.</p>
<pre><code class="hljs">protoc -o /tmp/metrics<span class="hljs-selector-class">.desc</span> metrics<span class="hljs-selector-class">.proto</span>
</code></pre>
<h3><a class="anchor" aria-hidden="true" id="supervisor-spec-json"></a><a href="#supervisor-spec-json" aria-hidden="true" class="hash-link"><svg class="hash-link-icon" aria-hidden="true" height="16" version="1.1" viewBox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"></path></svg></a>Supervisor spec JSON</h3>
<p>Below is the complete Supervisor spec JSON to be submitted to the Overlord.
Please make sure these keys are properly configured for successful ingestion.</p>
<ul>
<li><code>descriptor</code> for the descriptor file URL.</li>
<li><code>protoMessageType</code> from the proto definition.</li>
<li>parseSpec <code>format</code> must be <code>json</code>.</li>
<li><code>topic</code> to subscribe. The topic is &quot;metrics_pb&quot; instead of &quot;metrics&quot;.</li>
<li><code>bootstrap.server</code> is the Kafka broker host.</li>
</ul>
<pre><code class="hljs css language-json">{
<span class="hljs-attr">"type"</span>: <span class="hljs-string">"kafka"</span>,
<span class="hljs-attr">"dataSchema"</span>: {
<span class="hljs-attr">"dataSource"</span>: <span class="hljs-string">"metrics-kafka2"</span>,
<span class="hljs-attr">"parser"</span>: {
<span class="hljs-attr">"type"</span>: <span class="hljs-string">"protobuf"</span>,
<span class="hljs-attr">"descriptor"</span>: <span class="hljs-string">"file:///tmp/metrics.desc"</span>,
<span class="hljs-attr">"protoMessageType"</span>: <span class="hljs-string">"Metrics"</span>,
<span class="hljs-attr">"parseSpec"</span>: {
<span class="hljs-attr">"format"</span>: <span class="hljs-string">"json"</span>,
<span class="hljs-attr">"timestampSpec"</span>: {
<span class="hljs-attr">"column"</span>: <span class="hljs-string">"timestamp"</span>,
<span class="hljs-attr">"format"</span>: <span class="hljs-string">"auto"</span>
},
<span class="hljs-attr">"dimensionsSpec"</span>: {
<span class="hljs-attr">"dimensions"</span>: [
<span class="hljs-string">"unit"</span>,
<span class="hljs-string">"http_method"</span>,
<span class="hljs-string">"http_code"</span>,
<span class="hljs-string">"page"</span>,
<span class="hljs-string">"metricType"</span>,
<span class="hljs-string">"server"</span>
],
<span class="hljs-attr">"dimensionExclusions"</span>: [
<span class="hljs-string">"timestamp"</span>,
<span class="hljs-string">"value"</span>
]
}
}
},
<span class="hljs-attr">"metricsSpec"</span>: [
{
<span class="hljs-attr">"name"</span>: <span class="hljs-string">"count"</span>,
<span class="hljs-attr">"type"</span>: <span class="hljs-string">"count"</span>
},
{
<span class="hljs-attr">"name"</span>: <span class="hljs-string">"value_sum"</span>,
<span class="hljs-attr">"fieldName"</span>: <span class="hljs-string">"value"</span>,
<span class="hljs-attr">"type"</span>: <span class="hljs-string">"doubleSum"</span>
},
{
<span class="hljs-attr">"name"</span>: <span class="hljs-string">"value_min"</span>,
<span class="hljs-attr">"fieldName"</span>: <span class="hljs-string">"value"</span>,
<span class="hljs-attr">"type"</span>: <span class="hljs-string">"doubleMin"</span>
},
{
<span class="hljs-attr">"name"</span>: <span class="hljs-string">"value_max"</span>,
<span class="hljs-attr">"fieldName"</span>: <span class="hljs-string">"value"</span>,
<span class="hljs-attr">"type"</span>: <span class="hljs-string">"doubleMax"</span>
}
],
<span class="hljs-attr">"granularitySpec"</span>: {
<span class="hljs-attr">"type"</span>: <span class="hljs-string">"uniform"</span>,
<span class="hljs-attr">"segmentGranularity"</span>: <span class="hljs-string">"HOUR"</span>,
<span class="hljs-attr">"queryGranularity"</span>: <span class="hljs-string">"NONE"</span>
}
},
<span class="hljs-attr">"tuningConfig"</span>: {
<span class="hljs-attr">"type"</span>: <span class="hljs-string">"kafka"</span>,
<span class="hljs-attr">"maxRowsPerSegment"</span>: <span class="hljs-number">5000000</span>
},
<span class="hljs-attr">"ioConfig"</span>: {
<span class="hljs-attr">"topic"</span>: <span class="hljs-string">"metrics_pb"</span>,
<span class="hljs-attr">"consumerProperties"</span>: {
<span class="hljs-attr">"bootstrap.servers"</span>: <span class="hljs-string">"localhost:9092"</span>
},
<span class="hljs-attr">"taskCount"</span>: <span class="hljs-number">1</span>,
<span class="hljs-attr">"replicas"</span>: <span class="hljs-number">1</span>,
<span class="hljs-attr">"taskDuration"</span>: <span class="hljs-string">"PT1H"</span>
}
}
</code></pre>
<h2><a class="anchor" aria-hidden="true" id="kafka-producer"></a><a href="#kafka-producer" aria-hidden="true" class="hash-link"><svg class="hash-link-icon" aria-hidden="true" height="16" version="1.1" viewBox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"></path></svg></a>Kafka Producer</h2>
<p>Here is the sample script that publishes the metrics to Kafka in Protobuf format.</p>
<ol>
<li>Run <code>protoc</code> again with the Python binding option. This command generates <code>metrics_pb2.py</code> file.</li>
</ol>
<pre><code class="hljs"> protoc -o metrics<span class="hljs-selector-class">.desc</span> metrics<span class="hljs-selector-class">.proto</span> --python_out=.
</code></pre>
<ol start="2">
<li>Create Kafka producer script.</li>
</ol>
<p>This script requires <code>protobuf</code> and <code>kafka-python</code> modules.</p>
<pre><code class="hljs css language-python"><span class="hljs-comment">#!/usr/bin/env python</span>
<span class="hljs-keyword">import</span> sys
<span class="hljs-keyword">import</span> json
<span class="hljs-keyword">from</span> kafka <span class="hljs-keyword">import</span> KafkaProducer
<span class="hljs-keyword">from</span> metrics_pb2 <span class="hljs-keyword">import</span> Metrics
producer = KafkaProducer(bootstrap_servers=<span class="hljs-string">'localhost:9092'</span>)
topic = <span class="hljs-string">'metrics_pb'</span>
metrics = Metrics()
<span class="hljs-keyword">for</span> row <span class="hljs-keyword">in</span> iter(sys.stdin):
d = json.loads(row)
<span class="hljs-keyword">for</span> k, v <span class="hljs-keyword">in</span> d.items():
setattr(metrics, k, v)
pb = metrics.SerializeToString()
producer.send(topic, pb)
</code></pre>
<ol start="3">
<li>run producer</li>
</ol>
<pre><code class="hljs">./bin/<span class="hljs-keyword">generate</span>-example-metrics | ./pb_publisher<span class="hljs-variable">.py</span>
</code></pre>
<ol start="4">
<li>test</li>
</ol>
<pre><code class="hljs"><span class="hljs-comment">kafka</span><span class="hljs-literal">-</span><span class="hljs-comment">console</span><span class="hljs-literal">-</span><span class="hljs-comment">consumer</span> <span class="hljs-literal">-</span><span class="hljs-literal">-</span><span class="hljs-comment">zookeeper</span> <span class="hljs-comment">localhost</span> <span class="hljs-literal">-</span><span class="hljs-literal">-</span><span class="hljs-comment">topic</span> <span class="hljs-comment">metrics_pb</span>
</code></pre>
<p>It should print messages like this</p>
<pre><code class="hljs">millisecondsGETR"2017<span class="hljs-string">-04</span><span class="hljs-string">-06</span>T03:23:56Z*2002/list:request/latencyBwww1.example.com
</code></pre>
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