Exception when connecting to Cassandra with CQL using DataStax Java driver 1.0.4

问题

I have Cassandra 1.2.11 running on my laptop. I can connect to it using nodetool and cqlsh but when I try and use the DataStax 1.0.4 Java API to connect using CQL 3.0 I get the following error:

com.datastax.driver.core.exceptions.NoHostAvailableException: All host(s) tried for query failed (tried: localhost/127.0.0.1 ([localhost/127.0.0.1] Unexpected error during transport initialization (com.datastax.driver.core.TransportException: [localhost/127.0.0.1] Channel has been closed)))
    at com.datastax.driver.core.ControlConnection.reconnectInternal(ControlConnection.java:186)

I am using the following code to connect, taken from the DataStax documentation. I have tried several port number, including leaving the withPort() call out but nothing seems to work.

Cluster cluster = new Cluster.Builder()
        .addContactPoints("localhost")
        .withPort(9160)
        .build();

Using telnet I can verify that the Cassandra server is definitely listening at each of the ports I have specified. I have also verified that all the required library jar files are on my classpath as described in the documentation.

回答1:

It turns out I missed a section in the documentation.

I was using an old cassandra.yaml configuration file from an earlier version of Cassandra and it didn't enable the Native Transport binary protocol. The following snippet shows the settings that I needed to change:

# Whether to start the native transport server.
start_native_transport: true
# port for the CQL native transport to listen for clients on
native_transport_port: 9042

After restarting Cassandra the client was able to connect successfully and run CQL 3.0 commands. Note that the code to create the connection must be changed to use the port specified in the file, like this:

Cluster cluster = new Cluster.Builder()
        .addContactPoints("localhost")
        .withPort(9042)
        .build();

Also, note that from Cassandra 1.2.5 and above, the native transport is enabled by default.

回答2:

You also get this error when trying to use an old version of the java driver with a newer cassandra version.

回答3:

I have the same issue in Ubuntu. I installed recently with the below command which was the datastax guideline

apt-get install cassandra=2.0.11 dsc20=2.0.11-1

before that I used just

apt-get install cassandra

then it makes the same issue for me. I just removed then installed it with the first command (datastax guideline).

P.S. For remove the cassandra use below command

apt-get purge cassandra

来源：https://stackoverflow.com/questions/20409470/exception-when-connecting-to-cassandra-with-cql-using-datastax-java-driver-1-0-4

标签

java

cassandra

cql3

datastax-java-driver