Spark job does not exit/stop when running on Mac OS X - macos

Question

I try to run a spark job on my local Mac OS, the entire job finishes fine, but the job just doesn't finish and hangs there.
When a Spark job finished gracefully, it'll shutdown all of its spawned processes and released all its associated port numbers and have soemthing like below in its console:
17/09/26 12:04:42 INFO SparkContext: Invoking stop() from shutdown hook
17/09/26 12:04:42 INFO SparkUI: Stopped Spark web UI at http://172.29.16.34:4040
17/09/26 12:04:42 INFO MapOutputTrackerMasterEndpoint: MapOutputTrackerMasterEndpoint stopped!
17/09/26 12:04:42 INFO MemoryStore: MemoryStore cleared
17/09/26 12:04:42 INFO BlockManager: BlockManager stopped
17/09/26 12:04:42 INFO BlockManagerMaster: BlockManagerMaster stopped
17/09/26 12:04:42 INFO OutputCommitCoordinator$OutputCommitCoordinatorEndpoint: OutputCommitCoordinator stopped!
17/09/26 12:04:42 INFO SparkContext: Successfully stopped SparkContext
17/09/26 12:04:42 INFO ShutdownHookManager: Shutdown hook called
17/09/26 12:04:42 INFO ShutdownHookManager: Deleting directory /private/var/folders/mc/fl1dm0jx48d086s5jsk18dtc0000gn/T/spark-088260a7-6c27-4dbf-878a-ec6a2efa14a3
I tried to debug what's going on with this Spark job, initially I thought something is hanging there, but until I put a print out line right at the end of my spark job and that line got printed out, I got confused what could be causing it to hang over there?
Any help please?
My spark: 1.0.1
My OS X: 10.11.6
Here's my spark job code:
SparkConf sparkConf = new SparkConf();
SparkContext sparkContext = new SparkContext(sparkConf);
JavaSparkContext sc = new JavaSparkContext(sparkContext);
Configuration conf = HBaseConfiguration.create();
conf.set("hbase.zookeeper.quorum", zkQuorum);
conf.set("zookeeper.znode.parent", zkZNodeParent);
JavaPairRDD<ImmutableBytesWritable, Result> hBasePairRdd = sc.newAPIHadoopRDD(conf, TableInputFormat.class, ImmutableBytesWritable.class, Result.class);
EmbeddedSolrServer server = solrManager.setupSolrServer(shardIndex);
Thanks!
Actually, I just figured it out.
Thanks #shridharama for poking me to post some example source code of my spark job here.
Then I basically did a binary search of my code to see which part that was causing it from shutting down gracefully.
Then I eventually narrowed down to this single line:
EmbeddedSolrServer server = solrManager.setupSolrServer(shardIndex);
We use Spark job to build our solr index, this server process is never stopped.
So, then I happily added this line:
server.close();
And my spark job exits nicely on my Mac. Thanks!
But still, I don't understand how come this exact same spark job (same code, just different zookeeper configurations) could exit gracefully when running on my cluster?
Cheers!