Revert "SNOW-811265 Do not close channel on rebalance (#651)" (#678)

src/main/java/com/snowflake/kafka/connector/internal/streaming/SnowflakeSinkServiceV2.java

@@ -304,15 +304,14 @@ public void closeAll() {
   /**
    * This function is called during rebalance.
    *
-   * <p>We don't close the channels. Upon rebalance, (inside {@link
-   * com.snowflake.kafka.connector.SnowflakeSinkTask#open(Collection)} we will reopen the channel
-   * anyways. [Check c'tor of {@link TopicPartitionChannel}]
+   * <p>All the channels are closed. The client is still active. Upon rebalance, (inside {@link
+   * com.snowflake.kafka.connector.SnowflakeSinkTask#open(Collection)} we will reopen the channel.
    *
    * <p>We will wipe the cache partitionsToChannel so that in {@link
    * com.snowflake.kafka.connector.SnowflakeSinkTask#open(Collection)} we reinstantiate and fetch
    * offsetToken
    *
-   * @param partitions a list of topic partitions to close/shutdown
+   * @param partitions a list of topic partition
    */
   @Override
   public void close(Collection<TopicPartition> partitions) {
@@ -324,16 +323,15 @@ public void close(Collection<TopicPartition> partitions) {
               partitionsToChannel.get(partitionChannelKey);
           // Check for null since it's possible that the something goes wrong even before the
           // channels are created
+          if (topicPartitionChannel != null) {
+            topicPartitionChannel.closeChannel();
+          }
           LOGGER.info(
-              "Removing partitionChannel:{}, partition:{}, topic:{} from map(partitionsToChannel)",
+              "Closing partitionChannel:{}, partition:{}, topic:{}",
               topicPartitionChannel == null ? null : topicPartitionChannel.getChannelName(),
               topicPartition.topic(),
               topicPartition.partition());
         });
-    LOGGER.info(
-        "Closing {} partitions and Clearing partitionsToChannel Map of size:{}",
-        partitions.size(),
-        partitionsToChannel.size());
     partitionsToChannel.clear();
   }