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| <p>This Apache Druid extension enables Druid to ingest and understand the Protobuf data format. Make sure to <a href="/docs/0.19.0/development/extensions.html#loading-extensions">include</a> <code>druid-protobuf-extensions</code> as an extension.</p> |
| <p>The <code>druid-protobuf-extensions</code> provides the <a href="/docs/0.19.0/ingestion/data-formats.html#protobuf-parser">Protobuf Parser</a> |
| for <a href="/docs/0.19.0/ingestion/index.html#streaming">stream ingestion</a>. See corresponding docs for details.</p> |
| <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/0.19.0/tutorials/tutorial-kafka.html">Load from Kafka tutorial</a> first, and see <a href="/docs/0.19.0/development/extensions-core/kafka-ingestion.html">Kafka Indexing Service</a> documentation for more details.</p> |
| <p>The files used in this example are found at <a href="https://github.com/apache/druid/tree/master/examples/quickstart/protobuf"><code>./examples/quickstart/protobuf</code> in your Druid directory</a>.</p> |
| <p>For this example:</p> |
| <ul> |
| <li>Kafka broker host is <code>localhost:9092</code></li> |
| <li>Kafka topic is <code>metrics_pb</code></li> |
| <li>Datasource name is <code>metrics-protobuf</code></li> |
| </ul> |
| <p>Here is a JSON example of the 'metrics' data schema used in the 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 corresponding proto file for our 'metrics' dataset looks like this.</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>Next, we use the <code>protoc</code> Protobuf compiler to generate the descriptor file and save it as <code>metrics.desc</code>. The descriptor file must be either in the classpath or reachable by URL. In this example the descriptor file was saved at <code>/tmp/metrics.desc</code>, however this file is also available in the example files. From your Druid install directory:</p> |
| <pre><code class="hljs">protoc -o <span class="hljs-meta-keyword">/tmp/</span>metrics.desc .<span class="hljs-meta-keyword">/quickstart/</span>protobuf/metrics.proto |
| </code></pre> |
| <h2><a class="anchor" aria-hidden="true" id="create-kafka-supervisor"></a><a href="#create-kafka-supervisor" 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>Create Kafka Supervisor</h2> |
| <p>Below is the complete Supervisor spec JSON to be submitted to the Overlord. |
| Make sure these keys are properly configured for successful ingestion.</p> |
| <p>Important supervisor properties</p> |
| <ul> |
| <li><code>descriptor</code> for the descriptor file URL</li> |
| <li><code>protoMessageType</code> from the proto definition</li> |
| <li><code>parser</code> should have <code>type</code> set to <code>protobuf</code>, but note that the <code>format</code> of the <code>parseSpec</code> must be <code>json</code></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-protobuf"</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="adding-protobuf-messages-to-kafka"></a><a href="#adding-protobuf-messages-to-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>Adding Protobuf messages to Kafka</h2> |
| <p>If necessary, from your Kafka installation directory run the following command to create the Kafka topic</p> |
| <pre><code class="hljs"><span class="hljs-string">./bin/kafka-topics.sh</span> <span class="hljs-params">--create</span> <span class="hljs-params">--zookeeper</span> localhost<span class="hljs-function">:2181</span> <span class="hljs-params">--replication-factor</span> 1 <span class="hljs-params">--partitions</span> 1 <span class="hljs-params">--topic</span> metrics_pb |
| </code></pre> |
| <p>This example script requires <code>protobuf</code> and <code>kafka-python</code> modules. With the topic in place, messages can be inserted running the following command from your Druid installation directory</p> |
| <pre><code class="hljs">./bin/<span class="hljs-keyword">generate</span>-example-metrics | ./quickstart/protobuf/pb_publisher<span class="hljs-variable">.py</span> |
| </code></pre> |
| <p>You can confirm that data has been inserted to your Kafka topic using the following command from your Kafka installation directory</p> |
| <pre><code class="hljs"><span class="hljs-string">./bin/kafka-console-consumer</span> <span class="hljs-params">--zookeeper</span> localhost <span class="hljs-params">--topic</span> metrics_pb |
| </code></pre> |
| <p>which 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> |
| <p>If your supervisor created in the previous step is running, the indexing tasks should begin producing the messages and the data will soon be available for querying in Druid.</p> |
| <h2><a class="anchor" aria-hidden="true" id="generating-the-example-files"></a><a href="#generating-the-example-files" 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>Generating the example files</h2> |
| <p>The files provided in the example quickstart can be generated in the following manner starting with only <code>metrics.proto</code>.</p> |
| <h3><a class="anchor" aria-hidden="true" id="metricsdesc"></a><a href="#metricsdesc" 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><code>metrics.desc</code></h3> |
| <p>The descriptor file is generated using <code>protoc</code> Protobuf compiler. Given a <code>.proto</code> file, a <code>.desc</code> file can be generated like so.</p> |
| <pre><code class="hljs"><span class="hljs-selector-tag">protoc</span> <span class="hljs-selector-tag">-o</span> <span class="hljs-selector-tag">metrics</span><span class="hljs-selector-class">.desc</span> <span class="hljs-selector-tag">metrics</span><span class="hljs-selector-class">.proto</span> |
| </code></pre> |
| <h3><a class="anchor" aria-hidden="true" id="metrics_pb2py"></a><a href="#metrics_pb2py" 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><code>metrics_pb2.py</code></h3> |
| <p><code>metrics_pb2.py</code> is also generated with <code>protoc</code></p> |
| <pre><code class="hljs"> protoc -o metrics.<span class="hljs-keyword">desc</span> metrics.proto <span class="hljs-comment">--python_out=.</span> |
| </code></pre> |
| <h3><a class="anchor" aria-hidden="true" id="pb_publisherpy"></a><a href="#pb_publisherpy" 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><code>pb_publisher.py</code></h3> |
| <p>After <code>metrics_pb2.py</code> is generated, another script can be constructed to parse JSON data, convert it to Protobuf, and produce to a Kafka topic</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> |
| |
| <span class="hljs-keyword">for</span> row <span class="hljs-keyword">in</span> iter(sys.stdin): |
| d = json.loads(row) |
| metrics = Metrics() |
| <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) |
| |
| producer.flush() |
| </code></pre> |
| </span></div></article></div><div class="docs-prevnext"><a class="docs-prev button" href="/docs/0.19.0/development/extensions-core/postgresql.html"><span class="arrow-prev">← </span><span class="function-name-prevnext">PostgreSQL Metadata Store</span></a><a class="docs-next button" href="/docs/0.19.0/development/extensions-core/s3.html"><span>S3-compatible</span><span class="arrow-next"> →</span></a></div></div></div><nav class="onPageNav"><ul class="toc-headings"><li><a href="#example-load-protobuf-messages-from-kafka">Example: Load Protobuf messages from Kafka</a><ul class="toc-headings"><li><a href="#proto-file">Proto file</a></li><li><a href="#descriptor-file">Descriptor file</a></li></ul></li><li><a href="#create-kafka-supervisor">Create Kafka Supervisor</a></li><li><a href="#adding-protobuf-messages-to-kafka">Adding Protobuf messages to Kafka</a></li><li><a href="#generating-the-example-files">Generating the example files</a><ul class="toc-headings"><li><a href="#metricsdesc"><code>metrics.desc</code></a></li><li><a href="#metrics_pb2py"><code>metrics_pb2.py</code></a></li><li><a href="#pb_publisherpy"><code>pb_publisher.py</code></a></li></ul></li></ul></nav></div><footer class="nav-footer druid-footer" id="footer"><div class="container"><div class="text-center"><p><a href="/technology">Technology</a> · <a href="/use-cases">Use Cases</a> · <a href="/druid-powered">Powered by Druid</a> · <a href="/docs/0.19.0/">Docs</a> · <a href="/community/">Community</a> · <a href="/downloads.html">Download</a> · <a href="/faq">FAQ</a></p></div><div class="text-center"><a title="Join the user group" href="https://groups.google.com/forum/#!forum/druid-user" target="_blank"><span class="fa fa-comments"></span></a> · <a title="Follow Druid" href="https://twitter.com/druidio" target="_blank"><span class="fab fa-twitter"></span></a> · <a title="Download via Apache" href="https://www.apache.org/dyn/closer.cgi?path=/incubator/druid/{{ site.druid_versions[0].versions[0].version }}/apache-druid-{{ site.druid_versions[0].versions[0].version }}-bin.tar.gz" target="_blank"><span class="fas fa-feather"></span></a> · <a title="GitHub" href="https://github.com/apache/druid" target="_blank"><span class="fab fa-github"></span></a></div><div class="text-center license">Copyright © 2019 <a href="https://www.apache.org/" target="_blank">Apache Software Foundation</a>.<br/>Except where otherwise noted, licensed under <a rel="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA 4.0</a>.<br/>Apache Druid, Druid, and the Druid logo are either registered trademarks or trademarks of The Apache Software Foundation in the United States and other countries.</div></div></footer></div><script type="text/javascript" src="https://cdn.jsdelivr.net/docsearch.js/1/docsearch.min.js"></script><script> |
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