java - Error while trying to import data from mysql to cassandra using sqoop -

i installed dse , set path in .bashrc , sqoop-env.sh. fisrt ran dse using command

cd dse/bin  sudo sh dse-env.sh 

then started job tracker , task tracker process using command

~/dse/bin/dse cassandra -t 

i tried importing database person.empl,to created empty column family emp of keyspace comp using command

~/dse/bin/dse sqoop cql-import --table empl --cassandra-keyspace comp --cassandra-table emp --connect jdbc:mysql://127.0.0.1/person --username root --password root --cassandra-host 127.0.0.1 -m 1 

but getting following exception

exception in thread "main" java.lang.nosuchmethoderror: org.jboss.netty.handler.codec.frame.lengthfieldbasedframedecoder.<init>(iiiiiz)v     @ com.datastax.driver.core.frame$decoderv1.<init>(frame.java:179)     @ com.datastax.driver.core.frame$decoder.<clinit>(frame.java:162)     @ com.datastax.driver.core.connection$pipelinefactory.getpipeline(connection.java:1029)     @ org.jboss.netty.bootstrap.clientbootstrap.connect(clientbootstrap.java:212)     @ org.jboss.netty.bootstrap.clientbootstrap.connect(clientbootstrap.java:188)     @ com.datastax.driver.core.connection.<init>(connection.java:99)     @ com.datastax.driver.core.connection$factory.open(connection.java:573)     @ com.datastax.driver.core.controlconnection.tryconnect(controlconnection.java:244)     @ com.datastax.driver.core.controlconnection.reconnectinternal(controlconnection.java:190)     @ com.datastax.driver.core.controlconnection.connect(controlconnection.java:78)     @ com.datastax.driver.core.cluster$manager.init(cluster.java:1230)     @ com.datastax.driver.core.cluster.init(cluster.java:157)     @ com.datastax.driver.core.cluster.connect(cluster.java:245)     @ com.datastax.bdp.sqoop.sqooputil.setcqlimportoptions(sqooputil.java:146)     @ com.datastax.bdp.sqoop.cqlimportjob.configureoutputformat(cqlimportjob.java:79)     @ org.apache.sqoop.mapreduce.importjobbase.runimport(importjobbase.java:240)     @ com.datastax.bdp.sqoop.sqlmanageradapter.importtable(sqlmanageradapter.java:236)     @ org.apache.sqoop.tool.importtool.importtable(importtool.java:497)     @ org.apache.sqoop.tool.importtool.run(importtool.java:601)     @ org.apache.sqoop.sqoop.run(sqoop.java:143)     @ org.apache.hadoop.util.toolrunner.run(toolrunner.java:65)     @ org.apache.sqoop.sqoop.runsqoop(sqoop.java:179)     @ org.apache.sqoop.sqoop.runtool(sqoop.java:218)     @ org.apache.sqoop.sqoop.runtool(sqoop.java:227)     @ org.apache.sqoop.sqoop.main(sqoop.java:236)     @ com.cloudera.sqoop.sqoop.main(sqoop.java:57) 

version of nettyjar present in cassandra/lib 4.0.23 , in cassandra/tools/lib 3.9.0

can resolve this?