title: Why does my Spark application's web UI not show DAG visualization but History Server does?
body: <p>I am currently using IntelliJ IDEA to develop and run my Spark application. I have this set up in <code>conf/spark-defaults.conf</code>:</p>
  
  <pre><code>spark.eventLog.enabled           true
  spark.eventLog.dir               file:/home/user/spark-2.2.0/spark-events
  spark.history.fs.logDirectory    file:/home/user/spark-2.2.0/spark-events
  </code></pre>
  
  <p>In my application, I also have this:</p>
  
  <pre><code>val session = SparkSession.builder()
      .appName("MySparkApp")
      .master("spark://user:7077")
      .config("spark.jars", "target/mysparkapp.jar")
      .config("spark.eventLog.enabled","true")
      .config("spark.eventLog.dir","file:/home/user/spark-2.2.0/spark-events")
      .config("spark.history.fs.logDirectory","file:/home/user/spark-2.2.0/spark-events")
      .getOrCreate()
  </code></pre>
  
  <p>I can see DAG visualization in Spark History Server after the application finished. However, there is no DAG visualization shown in spark web ui. Any idea why this happened?</p>
  
  <p>I am using Mozilla Firefox for Ubuntu 57.0.1 (64-bit). And here is the screenshot of my history server:</p>
  
  <p><a href="https://i.stack.imgur.com/KYDuF.jpg" rel="noreferrer"><img src="https://i.stack.imgur.com/KYDuF.jpg" alt="enter image description here"></a></p>
  
  <p>And my WEB UI:</p>
  
  <p><a href="https://i.stack.imgur.com/7UPSM.jpg" rel="noreferrer"><img src="https://i.stack.imgur.com/7UPSM.jpg" alt="enter image description here"></a></p>