Failed to connect to hadoop cluster when accessing file from pyspark - hadoop

Question

I'm running the following code:
conf = SparkConf().setAppName("basicRegressionUbuntu").setMaster("spark://MyCUSTOMIP:7077")
sc = SparkContext(conf=conf)
rdd = sc.textFile("hdfs://MYHADOOPMASTERNODE:8020/sampleData/Sacramentorealestatetransactions.csv")
It throws the following:
16/03/25 10:01:11 WARN security.UserGroupInformation: PriviledgedActionException as:hduser (auth:SIMPLE) cause:java.io.IOException: Failed to connect to /10.0.2.15:42939
Exception in thread "main" java.io.IOException: Failed to connect to /10.0.2.15:42939
at org.apache.spark.network.client.TransportClientFactory.createClient(TransportClientFactory.java:216)
at org.apache.spark.network.client.TransportClientFactory.createClient(TransportClientFactory.java:167)
at org.apache.spark.rpc.netty.NettyRpcEnv.createClient(NettyRpcEnv.scala:200)
at org.apache.spark.rpc.netty.Outbox$$anon$1.call(Outbox.scala:187)
at org.apache.spark.rpc.netty.Outbox$$anon$1.call(Outbox.scala:183)
at java.util.concurrent.FutureTask.run(FutureTask.java:262)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.net.ConnectException: Connection timed out: /10.0.2.15:42939
at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:739)
at io.netty.channel.socket.nio.NioSocketChannel.doFinishConnect(NioSocketChannel.java:224)
at io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.finishConnect(AbstractNioChannel.java:289)
at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:528)
at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:468)
at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:382)
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:354)
at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:111)
... 1 more
I know that file path exists because when I SSH into MYHADOOPMASTERNODE and do an hdfs dfs -ls /sampleData/ it shows me the fille.
Any help would be much appreciated!