流式传输选项卡未显示结构化流式传输

Question

I am using structured streaming for reading csvs and writing to kafka. The streaming tab is not showing in Spark UI (not using streaming context).

val userSchema = new StructType().add("name", "string").add("age", "integer")
val csvDF = spark
  .readStream
  .option("sep", ";")
  .schema(userSchema)      // Specify schema of the csv files
  .csv("/path/to/directory") 

How can I get streaming metrics in the UI?

Answer 1

To see some metrics (in console), you need to add a listener

spark.streams.addListener(new StreamingQueryListener {
  override def onQueryStarted(event: StreamingQueryListener.QueryStartedEvent): Unit = logger.debug(s"QueryStarted [id = ${event.id}, name = ${event.name}, runId = ${event.runId}]")

  override def onQueryProgress(event: StreamingQueryListener.QueryProgressEvent): Unit = logger.warn(s"QueryProgress ${event.progress}")

  override def onQueryTerminated(event: StreamingQueryListener.QueryTerminatedEvent): Unit = logger.debug(s"QueryTerminated [id = ${event.id}, runId = ${event.runId}, error = ${event.exception}]")
})

QueryProgressEvent , displays info about offset, watermarks, source, sinks,etc.

This video can help you : Monitoring Structured Streaming Applications