使用spark streaming连接到Cassandra时出错

Question

I'm trying to create a keyspace and table using cassandra but I'm getting an error. In fact I'm trying to connect spark and cassandra.

I have the following code:

public static void main(String[] args){

    SparkConf sparkConf = new SparkConf().setAppName("org.kakfa.spark.ConsumerData").setMaster("local[4]");
    // Substitute 127.0.0.1 with the actual address of your Spark Master (or use "local" to run in local mode
    sparkConf.set("spark.cassandra.connection.host", "127.0.0.1");
    // Create the context with 2 seconds batch size
    JavaStreamingContext jssc = new JavaStreamingContext(sparkConf, new Duration(2000));

    Map<String, Integer> topicMap = new HashMap<>();
    String[] topics = KafkaProperties.TOPIC.split(",");
    for (String topic: topics) {
        topicMap.put(topic, KafkaProperties.NUM_THREADS);
    }
    /* connection to cassandra */
    CassandraConnector connector = CassandraConnector.apply(sparkConf);
    System.out.println("+++++++++++ cassandra connector created ++++++++++++++++++++++++++++");

    /* Receive kafka inputs */
    JavaPairReceiverInputDStream<String, String> messages =
            KafkaUtils.createStream(jssc, KafkaProperties.ZOOKEEPER, KafkaProperties.GROUP_CONSUMER, topicMap);
    System.out.println("+++++++++++++ streaming-kafka connection done +++++++++++++++++++++++++++");

    System.out.println(" -----  trying to create tables ------ ");

    try (Session session = connector.openSession()) {
        session.execute("DROP KEYSPACE IF EXISTS test");
        session.execute("CREATE KEYSPACE test WITH replication = {'class': 'SimpleStrategy', 'replication_factor': 1}");
        session.execute("CREATE TABLE test.users (id TEXT PRIMARY KEY, name TEXT)");
    }

    System.out.println("---- tables created ----");

But I'm getting the following error:

Exception in thread "main" com.datastax.driver.core.exceptions.NoHostAvailableException: All host(s) tried for query failed (tried: /127.0.0.1:9042 (com.datastax.driver.core.ConnectionException: [/127.0.0.1:9042] Unexpected error during transport initialization (com.datastax.driver.core.TransportException: [/127.0.0.1:9042] Connection has been closed)))
at com.datastax.driver.core.ControlConnection.reconnectInternal(ControlConnection.java:196)
at com.datastax.driver.core.ControlConnection.connect(ControlConnection.java:80)
at com.datastax.driver.core.Cluster$Manager.init(Cluster.java:1145)
at com.datastax.driver.core.Cluster.getMetadata(Cluster.java:313)
at com.datastax.spark.connector.cql.CassandraConnector$.com$datastax$spark$connector$cql$CassandraConnector$$createSession(CassandraConnector.scala:182)
at com.datastax.spark.connector.cql.CassandraConnector$$anonfun$2.apply(CassandraConnector.scala:161)
at com.datastax.spark.connector.cql.CassandraConnector$$anonfun$2.apply(CassandraConnector.scala:161)
at com.datastax.spark.connector.cql.RefCountedCache.createNewValueAndKeys(RefCountedCache.scala:36)
at com.datastax.spark.connector.cql.RefCountedCache.acquire(RefCountedCache.scala:61)
at com.datastax.spark.connector.cql.CassandraConnector.openSession(CassandraConnector.scala:70)
at org.kakfa.spark.ConsumerData.main(ConsumerData.java:73)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:144)

At first I thought it was the host, but then I changed the connection host to "local" getting the next error and I don't know what should I set here for not getting this:

Exception in thread "main" java.lang.IllegalArgumentException: Cannot build a cluster without contact points
at com.datastax.driver.core.Cluster.checkNotEmpty(Cluster.java:108)
at com.datastax.driver.core.Cluster.<init>(Cluster.java:100)
at com.datastax.driver.core.Cluster.buildFrom(Cluster.java:169)
at com.datastax.driver.core.Cluster$Builder.build(Cluster.java:1031)
at com.datastax.spark.connector.cql.CassandraConnector$.com$datastax$spark$connector$cql$CassandraConnector$$createSession(CassandraConnector.scala:179)
at com.datastax.spark.connector.cql.CassandraConnector$$anonfun$2.apply(CassandraConnector.scala:161)
at com.datastax.spark.connector.cql.CassandraConnector$$anonfun$2.apply(CassandraConnector.scala:161)
at com.datastax.spark.connector.cql.RefCountedCache.createNewValueAndKeys(RefCountedCache.scala:36)
at com.datastax.spark.connector.cql.RefCountedCache.acquire(RefCountedCache.scala:61)
at com.datastax.spark.connector.cql.CassandraConnector.openSession(CassandraConnector.scala:70)
at org.kakfa.spark.ConsumerData.main(ConsumerData.java:73)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:144)

Add that before anything I started cassandra by invoking 'bin/cassandra -f' from the command line.

Thanks!

Answer 1

The problem was that I had wrong dependencies.

If you want more information you can see the solution here .