[SPARK-31941] Handling the exception in SparkUI for getSparkUser method

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.4.6, 3.0.0, 3.1.0
• Fix Version/s: 2.4.7, 3.0.1, 3.1.0
• Component/s: Spark Core
• Assignee: Saurabh Chawla
• Reporter: Saurabh Chawla
• Created: 09/Jun/20 09:46
• Updated: 10/Jun/20 08:01
• Resolved: 10/Jun/20 07:53

Description

After SPARK-31632 SparkException is thrown from def applicationInfo(

  def applicationInfo(): v1.ApplicationInfo = {
    try {
      // The ApplicationInfo may not be available when Spark is starting up.
      store.view(classOf[ApplicationInfoWrapper]).max(1).iterator().next().info
    } catch {
      case _: NoSuchElementException =>
        throw new SparkException("Failed to get the application information. " +
          "If you are starting up Spark, please wait a while until it's ready.")
    }
  }

Where as the caller for this method def getSparkUser in Spark UI is not handling SparkException in the catch

  def getSparkUser: String = {
    try {
      Option(store.applicationInfo().attempts.head.sparkUser)
        .orElse(store.environmentInfo().systemProperties.toMap.get("user.name"))
        .getOrElse("<unknown>")
    } catch {
      case _: NoSuchElementException => "<unknown>"
    }
  }

So On using this method (getSparkUser )we can get the application erred out.

So either we should thow

 throw new NoSuchElementException("Failed to get the application information. " +
          "If you are starting up Spark, please wait a while until it's ready.")

or else add the scenario to catch spark exception in getSparkUser
case _: SparkException => "<unknown>"

Issue Links

• links to: [Github] Pull Request #28768 (SaurabhChawla100)
• links to: [Github] Pull Request #28768 (SaurabhChawla100)