[SPARK-42215][CONNECT] Simplify Scala Client IT tests

connector/connect/client/jvm/src/test/scala/org/apache/spark/sql/connect/client/util/RemoteSparkSession.scala

@@ -32,19 +32,11 @@ import org.apache.spark.util.Utils
 
 /**
  * An util class to start a local spark connect server in a different process for local E2E tests.
- * Pre-running the tests, the spark connect artifact needs to be built using e.g. `build/sbt
- * package`. It is designed to start the server once but shared by all tests. It is equivalent to
- * use the following command to start the connect server via command line:
+ * It calls the script `connector/connect/bin/spark-connect` to start the server.
  *
- * {{{
- * bin/spark-shell \
- * --jars `ls connector/connect/server/target/**/spark-connect*SNAPSHOT.jar | paste -sd ',' -` \
- * --conf spark.plugins=org.apache.spark.sql.connect.SparkConnectPlugin
- * }}}
- *
- * Set system property `spark.test.home` or env variable `SPARK_HOME` if the test is not executed
- * from the Spark project top folder. Set system property `spark.debug.sc.jvm.client=true` to
- * print the server process output in the console to debug server start stop problems.
+ * When starting the server the first time from a clean ./build/sbt clean, it may take a few
+ * minutes to compile the jars needed for the server. The subsequent runs may take around 1 min to
+ * start the server.
  */
 object SparkConnectServerUtils {
 
@@ -58,24 +50,15 @@ object SparkConnectServerUtils {
 
   private lazy val sparkConnect: Process = {
     debug("Starting the Spark Connect Server...")
-    val jar = findJar(
-      "connector/connect/server",
-      "spark-connect-assembly",
-      "spark-connect").getCanonicalPath
     val builder = Process(
       Seq(
-        "bin/spark-submit",
-        "--driver-class-path",
-        jar,
+        "connector/connect/bin/spark-connect",
         "--conf",
         s"spark.connect.grpc.binding.port=$port",
         "--conf",
         "spark.sql.catalog.testcat=org.apache.spark.sql.connect.catalog.InMemoryTableCatalog",
         "--conf",
-        "spark.sql.catalogImplementation=hive",
-        "--class",
-        "org.apache.spark.sql.connect.SimpleSparkConnectService",
-        jar),
+        "spark.sql.catalogImplementation=hive"),
       new File(sparkHome))
 
     val io = new ProcessIO(
@@ -123,8 +106,8 @@ trait RemoteSparkSession extends ConnectFunSuite with BeforeAndAfterAll {
     spark = SparkSession.builder().client(SparkConnectClient.builder().port(port).build()).build()
 
     // Retry and wait for the server to start
-    val stop = System.nanoTime() + TimeUnit.MINUTES.toNanos(1) // ~1 min
-    var sleepInternalMs = TimeUnit.SECONDS.toMillis(1) // 1s with * 2 backoff
+    val stop = System.nanoTime() + TimeUnit.MINUTES.toNanos(5) // ~5 min
+    val sleepInternalMs = TimeUnit.SECONDS.toMillis(5) // every 5s
     var success = false
     val error = new RuntimeException(s"Failed to start the test server on port $port.")
 
@@ -142,7 +125,6 @@ trait RemoteSparkSession extends ConnectFunSuite with BeforeAndAfterAll {
         case e: Throwable =>
           error.addSuppressed(e)
           Thread.sleep(sleepInternalMs)
-          sleepInternalMs *= 2
       }
     }
 

project/SparkBuild.scala

@@ -852,17 +852,6 @@ object SparkConnectClient {
       )
     },
 
-    buildTestDeps := {
-      (LocalProject("assembly") / Compile / Keys.`package`).value
-    },
-
-    // SPARK-42538: Make sure the `${SPARK_HOME}/assembly/target/scala-$SPARK_SCALA_VERSION/jars` is available for testing.
-    // At the same time, the build of `connect`, `connect-client-jvm` and `sql` will be triggered by `assembly` build,
-    // so no additional configuration is required.
-    test := ((Test / test) dependsOn (buildTestDeps)).value,
-
-    testOnly := ((Test / testOnly) dependsOn (buildTestDeps)).evaluated,
-
     (assembly / test) := { },
 
     (assembly / logLevel) := Level.Info,