I am successfully using the DataStax Java Driver to access Cassandra inside my Java code just before I start a MapReduce Job.
cluster = Cluster.builder().addContactPoint("127.0.0.1").build();
However I am needing to check additional information to decide on a per record basis how to reduce the record. If I attempt to use the same code inside a Hadoop Reducer class it fails to connect with the error:
INFO mapred.JobClient: Task Id :
attempt_201310280851_0012_r_000000_1, Status : FAILED
com.datastax.driver.core.exceptions.NoHostAvailableException:
All host(s) tried for query failed (tried: /127.0.0.1 ([/127.0.0.1]
Unexpected error during transport initialization
(com.datastax.driver.core.TransportException: [/127.0.0.1] Error writing)))
at com.datastax.driver.core.ControlConnection.reconnectInternal(ControlConnection.java:186)
at com.datastax.driver.core.ControlConnection.connect(ControlConnection.java:81)
at com.datastax.driver.core.Cluster$Manager.init(Cluster.java:662)
at com.datastax.driver.core.Cluster$Manager.access$100(Cluster.java:604)
at com.datastax.driver.core.Cluster.<init>(Cluster.java:69)
at com.datastax.driver.core.Cluster.buildFrom(Cluster.java:96)
at com.datastax.driver.core.Cluster$Builder.build(Cluster.java:585)
The MapReduce input and output will successfully read and write to Cassandra. As I mentioned I can connect before I run the job so I do not think it is an issue with the Cassandra server.
