fix test

externals/kyuubi-spark-sql-engine/src/test/scala/org/apache/kyuubi/engine/spark/session/SessionSuite.scala

@@ -17,6 +17,9 @@
 
 package org.apache.kyuubi.engine.spark.session
 
+import org.scalatest.concurrent.PatienceConfiguration.Timeout
+import org.scalatest.time.SpanSugar._
+
 import org.apache.kyuubi.Utils
 import org.apache.kyuubi.config.KyuubiConf._
 import org.apache.kyuubi.engine.spark.{SparkSQLEngine, WithSparkSQLEngine}
@@ -59,9 +62,10 @@ class SessionSuite extends WithSparkSQLEngine with JDBCTestUtils {
   override protected def jdbcUrl: String = s"jdbc:hive2://${engine.connectionUrl}/;"
 
   test("release session if shared level is CONNECTION") {
-    assert(engine.isAlive())
+    assert(engine.started.get)
     withJdbcStatement() {_ => }
-    Thread.sleep(5000)
-    assert(!engine.isAlive())
+    eventually(Timeout(10.seconds)) {
+      assert(!engine.started.get)
+    }
   }
 }

kyuubi-common/src/main/scala/org/apache/kyuubi/service/Serverable.scala

@@ -24,8 +24,7 @@ import org.apache.kyuubi.config.KyuubiConf
 abstract class Serverable(name: String) extends CompositeService(name) {
 
   private val OOMHook = new Runnable { override def run(): Unit = stop() }
-  private val started = new AtomicBoolean(false)
-  private val stopped = new AtomicBoolean(false)
+  private[kyuubi] val started = new AtomicBoolean(false)
 
   private[kyuubi] val backendService: AbstractBackendService
   private lazy val frontendService = new FrontendService(backendService, OOMHook)
@@ -61,11 +60,6 @@ abstract class Serverable(name: String) extends CompositeService(name) {
         case t: Throwable =>
           warn(s"Error stopping spark ${t.getMessage}", t)
       }
-      stopped.set(true)
     }
   }
-
-  def isAlive(): Boolean = {
-    started.get() && !stopped.get()
-  }
 }