I'm trying to connect to Cassandra from Java code using JDBC connection. Here are the jars I'm using
Now this is the code which I found in the Stackoverflow to do this:
String serverIP = "localhost";
String keyspace = "mykeyspace";
Cluster cluster = Cluster.builder()
.addContactPoints(serverIP)
.build();
Session session = cluster.connect(keyspace);
String cqlStatement = "SELECT * FROM users";
for (Row row : session.execute(cqlStatement)) {
System.out.println(row.toString());
}
But unfortunately it's throwing following exception:
log4j:WARN No appenders could be found for logger (com.datastax.driver.core.Cluster).
log4j:WARN Please initialize the log4j system properly.
Exception in thread "main" java.lang.NoSuchMethodError: org.jboss.netty.handler.codec.frame.LengthFieldBasedFrameDecoder.<init>(IIIIIZ)V
at com.datastax.driver.core.Frame$Decoder.<init>(Frame.java:130)
at com.datastax.driver.core.Connection$PipelineFactory.getPipeline(Connection.java:795)
at org.jboss.netty.bootstrap.ClientBootstrap.connect(ClientBootstrap.java:212)
at org.jboss.netty.bootstrap.ClientBootstrap.connect(ClientBootstrap.java:188)
at com.datastax.driver.core.Connection.<init>(Connection.java:93)
at com.datastax.driver.core.Connection$Factory.open(Connection.java:432)
at com.datastax.driver.core.ControlConnection.tryConnect(ControlConnection.java:216)
at com.datastax.driver.core.ControlConnection.reconnectInternal(ControlConnection.java:171)
at com.datastax.driver.core.ControlConnection.connect(ControlConnection.java:79)
at com.datastax.driver.core.Cluster$Manager.init(Cluster.java:1104)
at com.datastax.driver.core.Cluster.init(Cluster.java:121)
at com.datastax.driver.core.Cluster.connect(Cluster.java:198)
at com.datastax.driver.core.Cluster.connect(Cluster.java:226)
at com.mabsisa.resources.Demo.main(Demo.java:28)
I search in the internet for this exception scenario. But not much information I found. Please help me in solving this issue as I need to fix this issue as early as possible...
I think the problem comes from the netty version you are using. You are using the version 2.3.0 of netty and in that version the class
org.jboss.netty.handler.codec.frame.LengthFieldBasedFrameDecoder
does not have the constructor which the cassandra driver needs. In the maven repository the cassandra driver core has a depedency with the version 3.9.0.FINAL of netty:
http://mvnrepository.com/artifact/com.datastax.cassandra/cassandra-driver-core/2.0.2
So, try to update your version of netty.
Make sure you don't have two version of netty lying in your final build .
I had the same problem where i had two version of netty 3.2.2 and 3.9.0 , latest datastax driver needs 3.9.0 .
Related
I am starting the HiveThriftServer in Spark application by using :
HiveThriftServer2 .startWithContext(session.sqlContext());
I can see that i need to include hive-jdbc-1.2.1.spark2, hive-exec-1.2.1.spark2, hive-metastore-1.2.1.spark2 jars in the classpath to start it.
So far so good, it starts and i can see the "JDBC/ODBC" tab in Spark UI.
Now, in the client side (where i need to connect to this server to access the data), i have more advanced version of JARS like hive-jdbc-2.1.1 etc.
When i try to connect to the server with below code, i get an exception:
try {
Class.forName("org.apache.hive.jdbc.HiveDriver");
} catch (ClassNotFoundException e) {
System.out.println("Driver not found");
}
Connection con = DriverManager.getConnection("jdbc:hive2://<server-name>:10015/default", "", "");
Exception: Caused by: org.apache.thrift.TApplicationException: Required field 'client_protocol' is unset! Struct:TOpenSessionReq(client_protocol:null, configuration:{use:database=default})
at org.apache.thrift.TApplicationException.read(TApplicationException.java:111)
at org.apache.thrift.TServiceClient.receiveBase(TServiceClient.java:79)
at org.apache.hive.service.rpc.thrift.TCLIService$Client.recv_OpenSession(TCLIService.java:168)
at org.apache.hive.service.rpc.thrift.TCLIService$Client.OpenSession(TCLIService.java:155)
at org.apache.hive.jdbc.HiveConnection.openSession(HiveConnection.java:576)
And if i use the same version of JARS as server, its working.
Now i have two options:
1. Change JARS on server side to newer versions (2.1.1) , but then the server doesn't start(actually it complains for ClassNotFound issues). The HiveThriftServer2 class comes from spark-hive-thriftserver jar and if i look at its pom.xml, it has dependency of 1.2.1 jars , and that makes it obvious that server won't start on 2.1.1 versions
I change the version on client side,
But i don't have the option of changing the JAR version, as other applications in the App server are dependent on those versions.
Can anyone suggest any possible way to fix this? (Ideally the newer versions of jas should have backward compatibility)
thanks for the time. I am trying to access a remote Cassandra DB in order to complete my assertions. I see that the Server is running:
Cassandra V 3.0.8.1293
Driver Type: Cassandra CQL
Datastax Java Driver for Apache Cassandra - Core [3.0.5]
So, I am trying with the following simple code to access the DB
import com.datastax.driver.core.*
Cluster cluster = null;
try {
cluster = Cluster.builder().addContactPoint("x.x.x.x").withCredentials("xxxxxxx", "xxxxxx").withPort(9042).build()
Session session = cluster.connect();
ResultSet rs = session.execute("select * from TABLE");
Row row = rs.one();
} finally {
if (cluster != null) cluster.close();
}
when I use the cassandra-driver-core-2.0.1.jar I am getting the error :
ERROR:com.datastax.driver.core.exceptions.NoHostAvailableException: All host(s) tried for query failed (tried: /x.x.x.x(null))
Read the documentation and a lot of posts here and on other blogs and I saw that there may be an incompatibility with the driver version so I tried to upgrade the driver to many versions (cassandra-driver-core-2.5,cassandra-driver-core-3,cassandra-driver-core-3.2), but on that I am getting the following:
ERROR:java.lang.ExceptionInInitializerError
Have also tried to connect using JDBC, but to no avail, using the configuration proposed at this thread
SoapUI JDBC connection with Apache Cassandra
Actually I am running out of ideas. Can anyone propose or point to some direction on how to actually achieve this, either by pointing me to some tutorial or any idea.
Thank you very much
I think you haven't enable remote access to cassandra.
Try enabling remote access using below configuration -
File Path /etc/cassandra/default.conf/cassandra.yaml
rpc_address: 0.0.0.0
broadcast_rpc_address: <serverIPAddress>
After that, restart cassandra service.
Can we use Cassandra without Maven in Java? If so, how can we do that?
I've tried using it with JDBC DRIVER, but it is not helping the situation.
Check the DataStax Java Driver GitHub page, under the section "Getting the driver":
If you can't use a dependency management tool, a binary tarball is available for download.
Note that the link above is for the 3.2 version of the driver.
Untar the tarball, and put the following 3 JAR files into your classpath:
cassandra-driver-core-3.2.0.jar
cassandra-driver-mapping-3.2.0.jar
cassandra-driver-extras-3.2.0.jar
Once that is done, you can follow the "Quick Start" section of the linked manual:
import com.datastax.driver.core.Cluster;
import com.datastax.driver.core.Session;
import com.datastax.driver.core.ResultSet;
import com.datastax.driver.core.Row;
Cluster cluster = null;
try {
cluster = Cluster.builder()
.addContactPoint("127.0.0.1")
.build();
Session session = cluster.connect();
ResultSet rs = session.execute("select release_version from system.local");
Row row = rs.one();
System.out.println(row.getString("release_version"));
} finally {
if (cluster != null) cluster.close();
}
Note that the above "quick start" code is exactly that, and assumes that:
You are not using client-to-node SSL.
You are not using user authentication.
You are running Cassandra on your local machine, listening on 127.0.0.1
cluster = Cluster.builder()
.addContactPoint("localhost")
.build();
Exception in thread "main" java.lang.NoClassDefFoundError: com/google/common/util/concurrent/AsyncFunction
The only jars I have in my path are the 2 cassandra java driver jars cassandra-driver-core-2.1.10.3.jar and cassandra-driver-mapping-2.1.10.3.jar
Thanks
The issue is with missing guava.jar. Adding this in the class path solved (this) issue.
Overall issue is lack of suitable DataSatx documentaion
I am trying to connect to a local cassandra instance through a java client powered by Hector. I attempt to read rows after trying to connect. The code snippet is as follows
Cluster myCluster = HFactory.getOrCreateCluster("test" , "localhost:9160");
KeyspaceDefinition keySpaceDef = myCluster.describeKeyspace("testkeyspace");
.....
However the connectivity fails with this error
Exception in thread "main" java.lang.NoSuchFieldError: DEFAULT_MEMTABLE_OPERATIONS_IN_MILLIONS
at me.prettyprint.cassandra.service.ThriftCfDef.(ThriftCfDef.java:65)
at me.prettyprint.cassandra.service.ThriftCfDef.fromThriftList(ThriftCfDef.java:144)
at me.prettyprint.cassandra.service.ThriftKsDef.(ThriftKsDef.java:34)
at me.prettyprint.cassandra.service.AbstractCluster$4.execute(AbstractCluster.java:192)
at me.prettyprint.cassandra.service.AbstractCluster$4.execute(AbstractCluster.java:187)
at me.prettyprint.cassandra.service.Operation.executeAndSetResult(Operation.java:101)
at me.prettyprint.cassandra.connection.HConnectionManager.operateWithFailover(HConnectionManager.java:232)
at me.prettyprint.cassandra.service.AbstractCluster.describeKeyspace(AbstractCluster.java:201)
I have cassandra, thrift as dependencies in my pom.xml. Any clues as to what could be wrong?