When upgrading to HDP 2.2.8 using Ambari, Spark 1.2.1 is automatically upgraded to 1.3.1. However, if you wish to return to using 1.2.1:
Remove Spark 1.3.1 from your HDP cluster using Ambari:
curl -u admin:admin -H "X-Requested-By: ambari" -X DELETE
http://<AMBARI_HOST>:8080/api/v1/clusters/<CLUSTER_NAME>/services/SPARK
Manually install Spark 1.2.1 with HDP 2.2.6 Installing HDP Manually: Installing and Configuring Apache Spark.
