SQLHistoryListener

== SQLHistoryListener

SQLHistoryListener is a custom spark-sql-SQLListener.md[SQLListener] for index.md[History Server]. It attaches spark-sql-webui.md#creating-instance[SQL tab] to History Server's web UI only when the first spark-sql-SQLListener.md#SparkListenerSQLExecutionStart[SparkListenerSQLExecutionStart] arrives and shuts <> off. It also handles <>.

NOTE: Support for SQL UI in History Server was added in SPARK-11206 Support SQL UI on the history server.

CAUTION: FIXME Add the link to the JIRA.

=== [[onOtherEvent]] onOtherEvent

[source, scala]¶

onOtherEvent(event: SparkListenerEvent): Unit¶

When SparkListenerSQLExecutionStart event comes, onOtherEvent attaches spark-sql-webui.md#creating-instance[SQL tab] to web UI and passes the call to the parent spark-sql-SQLListener.md[SQLListener].

=== [[onTaskEnd]] onTaskEnd

CAUTION: FIXME

=== [[creating-instance]] Creating SQLHistoryListener Instance

SQLHistoryListener is created using a (private[sql]) SQLHistoryListenerFactory class (which is SparkHistoryListenerFactory).

The SQLHistoryListenerFactory class is registered when spark-webui-SparkUI.md#createHistoryUI[SparkUI creates a web UI for History Server] as a Java service in META-INF/services/org.apache.spark.scheduler.SparkHistoryListenerFactory:

org.apache.spark.sql.execution.ui.SQLHistoryListenerFactory

NOTE: Loading the service uses Java's https://docs.oracle.com/javase/8/docs/api/java/util/ServiceLoader.html#load-java.lang.Class-java.lang.ClassLoader-[ServiceLoader.load] method.

=== [[onExecutorMetricsUpdate]] onExecutorMetricsUpdate

onExecutorMetricsUpdate does nothing.