[SPARK-48763][CONNECT][BUILD][FOLLOW-UP] Move Spark Connect common/server into sql directory

### What changes were proposed in this pull request?

This PR is a followup of apache#47157 that moves `connect` into `sql/connect`.

### Why are the changes needed?

The reasons are as follow:
- There was a bit of question about moving `connect` as a standalone top level (apache#47157 (comment)).
- Technically all Spark Connect related code have to placed under `sql` just like Hive thrift server.
  - Spark Connect server is 99% SQL dedicated code for now
  - Spark Connect server already is using a lot of `spark.sql` configurations, e.g., `spark.sql.connect.serverStacktrace.enabled`
  - Spark Connect common is only for SQL module. If other components have to be implemented, that common has to be placed within that directory.

### Does this PR introduce _any_ user-facing change?

No.

### How was this patch tested?

CI in this PR should verify it.

### Was this patch authored or co-authored using generative AI tooling?

No.

Closes apache#47579 from HyukjinKwon/SPARK-48763-followup.

Authored-by: Hyukjin Kwon <gurwls223@apache.org>
Signed-off-by: Hyukjin Kwon <gurwls223@apache.org>

Author: HyukjinKwon

.github/labeler.yml

@@ -225,7 +225,7 @@ DEPLOY:
 CONNECT:
   - changed-files:
     - any-glob-to-any-file: [
-     'connect/**/*',
+     'sql/connect/**/*',
      'connector/connect/**/*',
      'python/pyspark/sql/**/connect/**/*',
      'python/pyspark/ml/**/connect/**/*'

.github/workflows/build_and_test.yml

@@ -606,7 +606,7 @@ jobs:
     - name: Breaking change detection against branch-3.5
       uses: bufbuild/buf-breaking-action@v1
       with:
-        input: connect/common/src/main
+        input: sql/connect/common/src/main
         against: 'https://github.com/apache/spark.git#branch=branch-3.5,subdir=connector/connect/common/src/main'
     - name: Install Python 3.9
       uses: actions/setup-python@v5

.github/workflows/build_python_connect.yml

@@ -84,7 +84,7 @@ jobs:
           # Start a Spark Connect server for local
           PYTHONPATH="python/lib/pyspark.zip:python/lib/py4j-0.10.9.7-src.zip:$PYTHONPATH" ./sbin/start-connect-server.sh \
             --driver-java-options "-Dlog4j.configurationFile=file:$GITHUB_WORKSPACE/conf/log4j2.properties" \
-            --jars "`find connect/server/target -name spark-connect-*SNAPSHOT.jar`,`find connector/protobuf/target -name spark-protobuf-*SNAPSHOT.jar`,`find connector/avro/target -name spark-avro*SNAPSHOT.jar`"
+            --jars "`find connector/protobuf/target -name spark-protobuf-*SNAPSHOT.jar`,`find connector/avro/target -name spark-avro*SNAPSHOT.jar`"
 
           # Remove Py4J and PySpark zipped library to make sure there is no JVM connection
           mv python/lib lib.back
@@ -104,7 +104,7 @@ jobs:
           PYTHONPATH="python/lib/pyspark.zip:python/lib/py4j-0.10.9.7-src.zip:$PYTHONPATH" ./sbin/start-connect-server.sh \
             --master "local-cluster[2, 4, 1024]" \
             --driver-java-options "-Dlog4j.configurationFile=file:$GITHUB_WORKSPACE/conf/log4j2.properties" \
-            --jars "`find connect/server/target -name spark-connect-*SNAPSHOT.jar`,`find connector/protobuf/target -name spark-protobuf-*SNAPSHOT.jar`,`find connector/avro/target -name spark-avro*SNAPSHOT.jar`"
+            --jars "`find connector/protobuf/target -name spark-protobuf-*SNAPSHOT.jar`,`find connector/avro/target -name spark-avro*SNAPSHOT.jar`"
 
           # Remove Py4J and PySpark zipped library to make sure there is no JVM connection
           mv python/lib lib.back

.github/workflows/build_python_connect35.yml

@@ -87,7 +87,7 @@ jobs:
           # Start a Spark Connect server for local
           PYTHONPATH="python/lib/pyspark.zip:python/lib/py4j-0.10.9.7-src.zip:$PYTHONPATH" ./sbin/start-connect-server.sh \
             --driver-java-options "-Dlog4j.configurationFile=file:$GITHUB_WORKSPACE/conf/log4j2.properties" \
-            --jars "`find connect/server/target -name spark-connect-*SNAPSHOT.jar`,`find connector/protobuf/target -name spark-protobuf-*SNAPSHOT.jar`,`find connector/avro/target -name spark-avro*SNAPSHOT.jar`"
+            --jars "`find connector/protobuf/target -name spark-protobuf-*SNAPSHOT.jar`,`find connector/avro/target -name spark-avro*SNAPSHOT.jar`"
 
           # Checkout to branch-3.5 to use the tests in branch-3.5.
           cd ..

.github/workflows/maven_test.yml

@@ -194,7 +194,7 @@ jobs:
           if [[ "$INCLUDED_TAGS" != "" ]]; then
             ./build/mvn $MAVEN_CLI_OPTS -pl "$TEST_MODULES" -Pyarn -Pkubernetes -Pvolcano -Phive -Phive-thriftserver -Phadoop-cloud -Pjvm-profiler -Pspark-ganglia-lgpl -Pkinesis-asl -Djava.version=${JAVA_VERSION/-ea} -Dtest.include.tags="$INCLUDED_TAGS" test -fae
           elif [[ "$MODULES_TO_TEST" == "connect" ]]; then
-            ./build/mvn $MAVEN_CLI_OPTS -Dtest.exclude.tags="$EXCLUDED_TAGS" -Djava.version=${JAVA_VERSION/-ea} -pl connector/connect/client/jvm,connect/common,connect/server test -fae
+            ./build/mvn $MAVEN_CLI_OPTS -Dtest.exclude.tags="$EXCLUDED_TAGS" -Djava.version=${JAVA_VERSION/-ea} -pl connector/connect/client/jvm,sql/connect/common,sql/connect/server test -fae
           elif [[ "$EXCLUDED_TAGS" != "" ]]; then
             ./build/mvn $MAVEN_CLI_OPTS -pl "$TEST_MODULES" -Pyarn -Pkubernetes -Pvolcano -Phive -Phive-thriftserver -Phadoop-cloud -Pjvm-profiler -Pspark-ganglia-lgpl -Pkinesis-asl -Djava.version=${JAVA_VERSION/-ea} -Dtest.exclude.tags="$EXCLUDED_TAGS" test -fae
           elif [[ "$MODULES_TO_TEST" == *"sql#hive-thriftserver"* ]]; then

connector/connect/client/jvm/src/test/scala/org/apache/spark/sql/ClientE2ETestSuite.scala

@@ -308,6 +308,7 @@ class ClientE2ETestSuite
     val testDataPath = java.nio.file.Paths
       .get(
         IntegrationTestUtils.sparkHome,
+        "sql",
         "connect",
         "common",
         "src",
@@ -347,6 +348,7 @@ class ClientE2ETestSuite
     val testDataPath = java.nio.file.Paths
       .get(
         IntegrationTestUtils.sparkHome,
+        "sql",
         "connect",
         "common",
         "src",
@@ -377,6 +379,7 @@ class ClientE2ETestSuite
     val testDataPath = java.nio.file.Paths
       .get(
         IntegrationTestUtils.sparkHome,
+        "sql",
         "connect",
         "common",
         "src",

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

@@ -71,7 +71,7 @@ import org.apache.spark.util.SparkFileUtils
  * compatibility.
  *
  * Note that the plan protos are used as the input for the `ProtoToParsedPlanTestSuite` in the
- * `connect/server` module
+ * `sql/connect/server` module
  */
 // scalastyle:on
 class PlanGenerationTestSuite
@@ -88,7 +88,7 @@ class PlanGenerationTestSuite
 
   protected val queryFilePath: Path = commonResourcePath.resolve("query-tests/queries")
 
-  // A relative path to /connect/server, used by `ProtoToParsedPlanTestSuite` to run
+  // A relative path to /sql/connect/server, used by `ProtoToParsedPlanTestSuite` to run
   // with the datasource.
   protected val testDataPath: Path = java.nio.file.Paths.get(
     "../",
@@ -3325,10 +3325,10 @@ class PlanGenerationTestSuite
   /* Protobuf functions */
   // scalastyle:off line.size.limit
   // If `common.desc` needs to be updated, execute the following command to regenerate it:
-  //  1. cd connect/common/src/main/protobuf/spark/connect
+  //  1. cd sql/connect/common/src/main/protobuf/spark/connect
   //  2. protoc --include_imports --descriptor_set_out=../../../../test/resources/protobuf-tests/common.desc common.proto
   // scalastyle:on line.size.limit
-  private val testDescFilePath: String = s"${IntegrationTestUtils.sparkHome}/connect/" +
+  private val testDescFilePath: String = s"${IntegrationTestUtils.sparkHome}/sql/connect/" +
     "common/src/test/resources/protobuf-tests/common.desc"
 
   // TODO(SPARK-45030): Re-enable this test when all Maven test scenarios succeed and there

connector/connect/client/jvm/src/test/scala/org/apache/spark/sql/streaming/ClientStreamingQuerySuite.scala

@@ -42,6 +42,7 @@ class ClientStreamingQuerySuite extends QueryTest with RemoteSparkSession with L
   private val testDataPath = Paths
     .get(
       IntegrationTestUtils.sparkHome,
+      "sql",
       "connect",
       "common",
       "src",

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

@@ -35,10 +35,17 @@ trait ConnectFunSuite extends AnyFunSuite { // scalastyle:ignore funsuite
   }
 
   protected def baseResourcePath: Path = {
-    getWorkspaceFilePath("connect", "client", "jvm", "src", "test", "resources").toAbsolutePath
+    getWorkspaceFilePath(
+      "sql",
+      "connect",
+      "client",
+      "jvm",
+      "src",
+      "test",
+      "resources").toAbsolutePath
   }
 
   protected def commonResourcePath: Path = {
-    getWorkspaceFilePath("connect", "common", "src", "test", "resources").toAbsolutePath
+    getWorkspaceFilePath("sql", "connect", "common", "src", "test", "resources").toAbsolutePath
   }
 }

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

@@ -60,7 +60,7 @@ object SparkConnectServerUtils {
   private lazy val sparkConnect: java.lang.Process = {
     debug("Starting the Spark Connect Server...")
     val connectJar =
-      findJar("connect/server", "spark-connect-assembly", "spark-connect").getCanonicalPath
+      findJar("sql/connect/server", "spark-connect-assembly", "spark-connect").getCanonicalPath
 
     val command = Seq.newBuilder[String]
     command += "bin/spark-submit"