[SPARK-26350][SS]Allow to override group id of the Kafka consumer

docs/structured-streaming-kafka-integration.md

@@ -379,7 +379,25 @@ The following configurations are optional:
   <td>string</td>
   <td>spark-kafka-source</td>
   <td>streaming and batch</td>
-  <td>Prefix of consumer group identifiers (`group.id`) that are generated by structured streaming queries</td>
+  <td>Prefix of consumer group identifiers (`group.id`) that are generated by structured streaming
+  queries. If "kafka.group.id" is set, this option will be ignored. </td>
+</tr>
+<tr>
+  <td>kafka.group.id</td>
+  <td>string</td>
+  <td>none</td>
+  <td>streaming and batch</td>
+  <td>The Kafka group id to use in Kafka consumer while reading from Kafka. Use this with caution.
+  By default, each query generates a unique group id for reading data. This ensures that each Kafka
+  source has its own consumer group that does not face interference from any other consumer, and
+  therefore can read all of the partitions of its subscribed topics. In some scenarios (for example,
+  Kafka group-based authorization), you may want to use a specific authorized group id to read data.
+  You can optionally set the group ID. However, do this with extreme caution as it can cause
+  unexpected behavior. Concurrently running queries (both, batch and streaming) or sources with the
+  same group id are likely interfere with each other causing each query to read only part of the
+  data. This may also occur when queries are started/restarted in quick succession. To minimize such
+  issues, set the Kafka consumer session timeout (by setting option "kafka.session.timeout.ms") to
+  be very small. When this is set, option "groupIdPrefix" will be ignored. </td>
 </tr>
 </table>
 
@@ -592,8 +610,9 @@ for parameters related to writing data.
 Note that the following Kafka params cannot be set and the Kafka source or sink will throw an exception:
 
 - **group.id**: Kafka source will create a unique group id for each query automatically. The user can
-set the prefix of the automatically generated group.id's via the optional source option `groupIdPrefix`, default value
-is "spark-kafka-source".
+set the prefix of the automatically generated group.id's via the optional source option `groupIdPrefix`,
+default value is "spark-kafka-source". You can also set "kafka.group.id" to force Spark to use a special
+group id, however, please read warnings for this option and use it with caution.
 - **auto.offset.reset**: Set the source option `startingOffsets` to specify
  where to start instead. Structured Streaming manages which offsets are consumed internally, rather
  than rely on the kafka Consumer to do it. This will ensure that no data is missed when new

external/kafka-0-10-sql/src/main/scala/org/apache/spark/sql/kafka010/KafkaContinuousReadSupport.scala

@@ -20,7 +20,7 @@ package org.apache.spark.sql.kafka010
 import java.{util => ju}
 import java.util.concurrent.TimeoutException
 
-import org.apache.kafka.clients.consumer.{ConsumerRecord, OffsetOutOfRangeException}
+import org.apache.kafka.clients.consumer.{ConsumerConfig, ConsumerRecord, OffsetOutOfRangeException}
 import org.apache.kafka.common.TopicPartition
 
 import org.apache.spark.TaskContext
@@ -167,7 +167,13 @@ class KafkaContinuousScanConfigBuilder(
 
     val deletedPartitions = oldStartPartitionOffsets.keySet.diff(currentPartitionSet)
     if (deletedPartitions.nonEmpty) {
-      reportDataLoss(s"Some partitions were deleted: $deletedPartitions")
+      val message = if (
+          offsetReader.driverKafkaParams.containsKey(ConsumerConfig.GROUP_ID_CONFIG)) {
+        s"$deletedPartitions are gone. ${KafkaSourceProvider.CUSTOM_GROUP_ID_ERROR_MESSAGE}"
+      } else {
+        s"$deletedPartitions are gone. Some data may have been missed"
+      }
+      reportDataLoss(message)
     }
 
     val startOffsets = newPartitionOffsets ++

external/kafka-0-10-sql/src/main/scala/org/apache/spark/sql/kafka010/KafkaMicroBatchReadSupport.scala

@@ -22,6 +22,7 @@ import java.io._
 import java.nio.charset.StandardCharsets
 
 import org.apache.commons.io.IOUtils
+import org.apache.kafka.clients.consumer.ConsumerConfig
 
 import org.apache.spark.SparkEnv
 import org.apache.spark.internal.Logging
@@ -122,7 +123,13 @@ private[kafka010] class KafkaMicroBatchReadSupport(
     // Find deleted partitions, and report data loss if required
     val deletedPartitions = startPartitionOffsets.keySet.diff(endPartitionOffsets.keySet)
     if (deletedPartitions.nonEmpty) {
-      reportDataLoss(s"$deletedPartitions are gone. Some data may have been missed")
+      val message =
+        if (kafkaOffsetReader.driverKafkaParams.containsKey(ConsumerConfig.GROUP_ID_CONFIG)) {
+          s"$deletedPartitions are gone. ${KafkaSourceProvider.CUSTOM_GROUP_ID_ERROR_MESSAGE}"
+        } else {
+          s"$deletedPartitions are gone. Some data may have been missed"
+        }
+      reportDataLoss(message)
     }
 
     // Use the end partitions to calculate offset ranges to ignore partitions that have

external/kafka-0-10-sql/src/main/scala/org/apache/spark/sql/kafka010/KafkaOffsetReader.scala

@@ -45,7 +45,7 @@ import org.apache.spark.util.{ThreadUtils, UninterruptibleThread}
  */
 private[kafka010] class KafkaOffsetReader(
     consumerStrategy: ConsumerStrategy,
-    driverKafkaParams: ju.Map[String, Object],
+    val driverKafkaParams: ju.Map[String, Object],
     readerOptions: Map[String, String],
     driverGroupIdPrefix: String) extends Logging {
   /**
@@ -81,7 +81,9 @@ private[kafka010] class KafkaOffsetReader(
     assert(Thread.currentThread().isInstanceOf[UninterruptibleThread])
     if (_consumer == null) {
       val newKafkaParams = new ju.HashMap[String, Object](driverKafkaParams)
-      newKafkaParams.put(ConsumerConfig.GROUP_ID_CONFIG, nextGroupId())
+      if (driverKafkaParams.get(ConsumerConfig.GROUP_ID_CONFIG) == null) {
+        newKafkaParams.put(ConsumerConfig.GROUP_ID_CONFIG, nextGroupId())
+      }
       _consumer = consumerStrategy.createConsumer(newKafkaParams)
     }
     _consumer

external/kafka-0-10-sql/src/main/scala/org/apache/spark/sql/kafka010/KafkaSource.scala

@@ -22,6 +22,7 @@ import java.io._
 import java.nio.charset.StandardCharsets
 
 import org.apache.commons.io.IOUtils
+import org.apache.kafka.clients.consumer.ConsumerConfig
 import org.apache.kafka.common.TopicPartition
 
 import org.apache.spark.SparkContext
@@ -241,7 +242,12 @@ private[kafka010] class KafkaSource(
 
     val deletedPartitions = fromPartitionOffsets.keySet.diff(untilPartitionOffsets.keySet)
     if (deletedPartitions.nonEmpty) {
-      reportDataLoss(s"$deletedPartitions are gone. Some data may have been missed")
+      val message = if (kafkaReader.driverKafkaParams.containsKey(ConsumerConfig.GROUP_ID_CONFIG)) {
+        s"$deletedPartitions are gone. ${KafkaSourceProvider.CUSTOM_GROUP_ID_ERROR_MESSAGE}"
+      } else {
+        s"$deletedPartitions are gone. Some data may have been missed"
+      }
+      reportDataLoss(message)
     }
 
     // Use the until partitions to calculate offset ranges to ignore partitions that have

external/kafka-0-10-sql/src/main/scala/org/apache/spark/sql/kafka010/KafkaSourceProvider.scala

@@ -340,9 +340,11 @@ private[kafka010] class KafkaSourceProvider extends DataSourceRegister
     // Validate user-specified Kafka options
 
     if (caseInsensitiveParams.contains(s"kafka.${ConsumerConfig.GROUP_ID_CONFIG}")) {
-      throw new IllegalArgumentException(
-        s"Kafka option '${ConsumerConfig.GROUP_ID_CONFIG}' is not supported as " +
-          s"user-specified consumer groups are not used to track offsets.")
+      logWarning(CUSTOM_GROUP_ID_ERROR_MESSAGE)
+      if (caseInsensitiveParams.contains(GROUP_ID_PREFIX)) {
+        logWarning("Option 'groupIdPrefix' will be ignored as " +
+          s"option 'kafka.${ConsumerConfig.GROUP_ID_CONFIG}' has been set.")
+      }
     }
 
     if (caseInsensitiveParams.contains(s"kafka.${ConsumerConfig.AUTO_OFFSET_RESET_CONFIG}")) {
@@ -445,6 +447,7 @@ private[kafka010] object KafkaSourceProvider extends Logging {
   private[kafka010] val ENDING_OFFSETS_OPTION_KEY = "endingoffsets"
   private val FAIL_ON_DATA_LOSS_OPTION_KEY = "failondataloss"
   private val MIN_PARTITIONS_OPTION_KEY = "minpartitions"
+  private val GROUP_ID_PREFIX = "groupidprefix"
 
   val TOPIC_OPTION_KEY = "topic"
 
@@ -464,7 +467,16 @@ private[kafka010] object KafkaSourceProvider extends Logging {
       | source option "failOnDataLoss" to "false".
     """.stripMargin
 
-
+  val CUSTOM_GROUP_ID_ERROR_MESSAGE =
+    s"""Kafka option 'kafka.${ConsumerConfig.GROUP_ID_CONFIG}' has been set on this query, it is
+       | not recommended to set this option. This option is unsafe to use since multiple concurrent
+       | queries or sources using the same group id will interfere with each other as they are part
+       | of the same consumer group. Restarted queries may also suffer interference from the
+       | previous run having the same group id. The user should have only one query per group id,
+       | and/or set the option 'kafka.session.timeout.ms' to be very small so that the Kafka
+       | consumers from the previous query are marked dead by the Kafka group coordinator before the
+       | restarted query starts running.
+    """.stripMargin
 
   private val serClassName = classOf[ByteArraySerializer].getName
   private val deserClassName = classOf[ByteArrayDeserializer].getName
@@ -515,7 +527,7 @@ private[kafka010] object KafkaSourceProvider extends Logging {
       .set(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "none")
 
       // So that consumers in executors do not mess with any existing group id
-      .set(ConsumerConfig.GROUP_ID_CONFIG, s"$uniqueGroupId-executor")
+      .setIfUnset(ConsumerConfig.GROUP_ID_CONFIG, s"$uniqueGroupId-executor")
 
       // So that consumers in executors does not commit offsets unnecessarily
       .set(ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG, "false")
@@ -534,7 +546,7 @@ private[kafka010] object KafkaSourceProvider extends Logging {
       parameters: Map[String, String],
       metadataPath: String): String = {
     val groupIdPrefix = parameters
-      .getOrElse("groupIdPrefix", "spark-kafka-source")
+      .getOrElse(GROUP_ID_PREFIX, "spark-kafka-source")
     s"${groupIdPrefix}-${UUID.randomUUID}-${metadataPath.hashCode}"
   }
 

external/kafka-0-10-sql/src/test/scala/org/apache/spark/sql/kafka010/KafkaMicroBatchSourceSuite.scala

@@ -581,6 +581,33 @@ abstract class KafkaMicroBatchSourceSuiteBase extends KafkaSourceSuiteBase {
     )
   }
 
+  test("allow group.id override") {
+    // Tests code path KafkaSourceProvider.{sourceSchema(.), createSource(.)}
+    // as well as KafkaOffsetReader.createConsumer(.)
+    val topic = newTopic()
+    testUtils.createTopic(topic, partitions = 3)
+    testUtils.sendMessages(topic, (1 to 10).map(_.toString).toArray, Some(0))
+    testUtils.sendMessages(topic, (11 to 20).map(_.toString).toArray, Some(1))
+    testUtils.sendMessages(topic, (21 to 30).map(_.toString).toArray, Some(2))
+
+    val dsKafka = spark
+      .readStream
+      .format("kafka")
+      .option("kafka.group.id", "id-" + Random.nextInt())
+      .option("kafka.bootstrap.servers", testUtils.brokerAddress)
+      .option("subscribe", topic)
+      .option("startingOffsets", "earliest")
+      .load()
+      .selectExpr("CAST(value AS STRING)")
+      .as[String]
+      .map(_.toInt)
+
+    testStream(dsKafka)(
+      makeSureGetOffsetCalled,
+      CheckAnswer(1 to 30: _*)
+    )
+  }
+
   test("ensure stream-stream self-join generates only one offset in log and correct metrics") {
     val topic = newTopic()
     testUtils.createTopic(topic, partitions = 2)
@@ -1185,7 +1212,6 @@ abstract class KafkaSourceSuiteBase extends KafkaSourceTest {
       assert(ex.getMessage.toLowerCase(Locale.ROOT).contains("not supported"))
     }
 
-    testUnsupportedConfig("kafka.group.id")
     testUnsupportedConfig("kafka.auto.offset.reset")
     testUnsupportedConfig("kafka.enable.auto.commit")
     testUnsupportedConfig("kafka.interceptor.classes")

external/kafka-0-10-sql/src/test/scala/org/apache/spark/sql/kafka010/KafkaRelationSuite.scala

@@ -239,6 +239,18 @@ class KafkaRelationSuite extends QueryTest with SharedSQLContext with KafkaTest
     testBadOptions("subscribePattern" -> "")("pattern to subscribe is empty")
   }
 
+  test("allow group.id overriding") {
+    // Tests code path KafkaSourceProvider.createRelation(.)
+    val topic = newTopic()
+    testUtils.createTopic(topic, partitions = 3)
+    testUtils.sendMessages(topic, (1 to 10).map(_.toString).toArray, Some(0))
+    testUtils.sendMessages(topic, (11 to 20).map(_.toString).toArray, Some(1))
+    testUtils.sendMessages(topic, (21 to 30).map(_.toString).toArray, Some(2))
+
+    val df = createDF(topic, withOptions = Map("kafka.group.id" -> "custom"))
+    checkAnswer(df, (1 to 30).map(_.toString).toDF())
+  }
+
   test("read Kafka transactional messages: read_committed") {
     val topic = newTopic()
     testUtils.createTopic(topic)