[LIVY-1059] Add livy.spark.yarn.queue configuration to set default YARN queue

conf/livy.conf.template

@@ -47,6 +47,10 @@
 # What spark deploy mode Livy sessions should use.
 # livy.spark.deploy-mode =
 
+# What default YARN queue Livy sessions should use if not specified in the client request.
+# By default, it is null and falls back to the global Hadoop cluster default queue.
+# livy.spark.yarn.queue = default
+
 # Configure Livy server http request and response header size.
 # livy.server.request-header.size = 131072
 # livy.server.response-header.size = 131072

server/src/main/scala/org/apache/livy/LivyConf.scala

@@ -44,6 +44,7 @@ object LivyConf {
   val SPARK_HOME = Entry("livy.server.spark-home", null)
   val LIVY_SPARK_MASTER = Entry("livy.spark.master", "local")
   val LIVY_SPARK_DEPLOY_MODE = Entry("livy.spark.deploy-mode", null)
+  val SPARK_YARN_QUEUE = Entry("livy.spark.yarn.queue", null)
 
   // Two configurations to specify Spark and related Scala version. These are internal
   // configurations will be set by LivyServer and used in session creation. It is not required to
@@ -485,6 +486,9 @@ class LivyConf(loadDefaults: Boolean) extends ClientConf[LivyConf](null) {
   /** Return the spark master Livy sessions should use. */
   def sparkMaster(): String = get(LIVY_SPARK_MASTER)
 
+  /** Return the default YARN queue Livy sessions should use. */
+  def sparkYarnQueue(): Option[String] = Option(get(SPARK_YARN_QUEUE)).filterNot(_.isEmpty)
+
   /** Return the path to the spark-submit executable. */
   def sparkSubmit(): String = {
     sparkHome().map { _ + File.separator + "bin" + File.separator + "spark-submit" }.get

server/src/main/scala/org/apache/livy/server/batch/BatchSession.scala

@@ -83,7 +83,7 @@ object BatchSession extends Logging {
       request.executorMemory.foreach(builder.executorMemory)
       request.executorCores.foreach(builder.executorCores)
       request.numExecutors.foreach(builder.numExecutors)
-      request.queue.foreach(builder.queue)
+      request.queue.orElse(livyConf.sparkYarnQueue()).foreach(builder.queue)
       request.name.foreach(builder.name)
 
       sessionStore.save(BatchSession.RECOVERY_SESSION_TYPE, s.recoveryMetadata)

server/src/main/scala/org/apache/livy/server/interactive/InteractiveSession.scala

@@ -107,7 +107,7 @@ object InteractiveSession extends Logging {
         SparkLauncher.EXECUTOR_MEMORY -> request.executorMemory.map(_.toString),
         "spark.executor.instances" -> request.numExecutors.map(_.toString),
         "spark.app.name" -> request.name.map(_.toString),
-        "spark.yarn.queue" -> request.queue
+        "spark.yarn.queue" -> request.queue.orElse(livyConf.sparkYarnQueue())
       )
 
       userOpts.foreach { case (key, opt) =>
@@ -152,7 +152,7 @@ object InteractiveSession extends Logging {
       request.jars,
       request.numExecutors,
       request.pyFiles,
-      request.queue,
+      request.queue.orElse(livyConf.sparkYarnQueue()),
       mockApp)
   }
 

server/src/test/scala/org/apache/livy/server/batch/BatchSessionSpec.scala

@@ -33,7 +33,7 @@ import org.apache.livy.{LivyBaseUnitTestSuite, LivyConf, Utils}
 import org.apache.livy.server.AccessManager
 import org.apache.livy.server.recovery.SessionStore
 import org.apache.livy.sessions.SessionState
-import org.apache.livy.utils.{AppInfo, Clock, SparkApp}
+import org.apache.livy.utils.{AppInfo, Clock, SparkApp, SparkProcessBuilder}
 
 class BatchSessionSpec
   extends FunSpec
@@ -138,6 +138,43 @@ class BatchSessionSpec
       }) should be (true)
     }
 
+    it("should pass default YARN queue to spark-submit when request queue is empty") {
+      val req = new CreateBatchRequest()
+      req.file = script.toString
+      req.queue = None
+      req.conf = Map("spark.driver.extraClassPath" -> sys.props("java.class.path"))
+
+      val conf = new LivyConf()
+        .set(LivyConf.LOCAL_FS_WHITELIST, sys.props("java.io.tmpdir"))
+        .set(LivyConf.SPARK_YARN_QUEUE, "livy-default-batch-queue")
+
+      val accessManager = new AccessManager(conf)
+      val batch = BatchSession.create(10, None, req, conf, accessManager, null, None, sessionStore)
+      batch.start()
+
+      Utils.waitUntil({ () => !batch.state.isActive }, Duration(10, TimeUnit.SECONDS))
+      batch.logLines().mkString should include("livy-default-batch-queue")
+    }
+
+    it("should prioritize user-specified request queue over LivyConf configuration") {
+      val req = new CreateBatchRequest()
+      req.file = script.toString
+      req.queue = Some("user-custom-batch-queue")
+      req.conf = Map("spark.driver.extraClassPath" -> sys.props("java.class.path"))
+
+      val conf = new LivyConf()
+        .set(LivyConf.LOCAL_FS_WHITELIST, sys.props("java.io.tmpdir"))
+        .set(LivyConf.SPARK_YARN_QUEUE, "livy-default-batch-queue")
+
+      val accessManager = new AccessManager(conf)
+      val batch = BatchSession.create(20, None, req, conf, accessManager, null, None, sessionStore)
+      batch.start()
+
+      Utils.waitUntil({ () => !batch.state.isActive }, Duration(10, TimeUnit.SECONDS))
+      batch.logLines().mkString should include("user-custom-batch-queue")
+      batch.logLines().mkString should not include "livy-default-batch-queue"
+    }
+
     def testRecoverSession(name: Option[String]): Unit = {
       val conf = new LivyConf()
       val req = new CreateBatchRequest()

server/src/test/scala/org/apache/livy/server/interactive/InteractiveSessionSpec.scala

@@ -322,4 +322,66 @@ class InteractiveSessionSpec extends FunSpec
       s.logLines().mkString should include("RSCDriver URI is unknown")
     }
   }
+
+  describe("InteractiveSession") {
+    it("should inherit the default YARN queue from LivyConf when request queue is empty") {
+      val testLivyConf = new LivyConf()
+        .set(LivyConf.REPL_JARS, "dummy.jar")
+        .set(LivyConf.SPARK_YARN_QUEUE, "livy-default-queue")
+
+      val req = new CreateInteractiveRequest()
+      req.kind = Spark
+      req.queue = None
+      req.conf = Map(RSCConf.Entry.LIVY_JARS.key() -> "")
+
+      val mockClient = Some(mock[RSCClient])
+
+      val s = InteractiveSession.create(
+        id = 101,
+        name = None,
+        owner = "systest",
+        proxyUser = None,
+        livyConf = testLivyConf,
+        accessManager = accessManager,
+        request = req,
+        sessionStore = mock[SessionStore],
+        ttl = None,
+        idleTimeout = None,
+        mockApp = None,
+        mockClient = mockClient
+      )
+
+      s.queue shouldBe Some("livy-default-queue")
+    }
+
+    it("should prioritize user-specified request queue over LivyConf global configuration") {
+      val testLivyConf = new LivyConf()
+        .set(LivyConf.REPL_JARS, "dummy.jar")
+        .set(LivyConf.SPARK_YARN_QUEUE, "livy-default-queue")
+
+      val req = new CreateInteractiveRequest()
+      req.kind = Spark
+      req.queue = Some("user-custom-queue")
+      req.conf = Map(RSCConf.Entry.LIVY_JARS.key() -> "")
+
+      val mockClient = Some(mock[RSCClient])
+
+      val s = InteractiveSession.create(
+        id = 102,
+        name = None,
+        owner = "systest",
+        proxyUser = None,
+        livyConf = testLivyConf,
+        accessManager = accessManager,
+        request = req,
+        sessionStore = mock[SessionStore],
+        ttl = None,
+        idleTimeout = None,
+        mockApp = None,
+        mockClient = mockClient
+      )
+
+      s.queue shouldBe Some("user-custom-queue")
+    }
+  }
 }