Sounds like your are getting this problem... 
http://www.mail-archive.com/user@cassandra.apache.org/msg06295.html

Should be fixed in the nightly build. You can still get the stats via JConsole. 

Aaron


On 12 Oct, 2010,at 01:14 PM, Dmitri Smirnov <dsmirnov@netflix.com> wrote:

Is below a normal thing? I am a newby, just unpacked and started a
single node.

$ bin/nodetool -h localhost -p 8080 version
ReleaseVersion: 0.7.0-beta2

$ bin/nodetool -h localhost -p 8080 tpstats
Pool Name Active Pending Completed
MIGRATION_STAGE 0 0 0
GOSSIP_STAGE 0 0 0
MESSAGING-SERVICE-POOL Exception in thread "main"
java.lang.reflect.UndeclaredThrowableException
at $Proxy4.getActiveCount(Unknown Source)
at
org.apache.cassandra.tools.NodeCmd.printThreadPoolStats(NodeCmd.java:157)
at org.apache.cassandra.tools.NodeCmd.main(NodeCmd.java:497)
Caused by: javax.management.AttributeNotFoundException: No such
attribute: ActiveCount
at
com.sun.jmx.mbeanserver.PerInterface.getAttribute(PerInterface.java:81)
at
com.sun.jmx.mbeanserver.MBeanSupport.getAttribute(MBeanSupport.java:205)
at
com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.getAttribute(DefaultMBeanServerInterceptor.java:683)
at
com.sun.jmx.mbeanserver.JmxMBeanServer.getAttribute(JmxMBeanServer.java:672)
at
javax.management.remote.rmi.RMIConnectionImpl.doOperation(RMIConnectionImpl.java:1427)
at
javax.management.remote.rmi.RMIConnectionImpl.access$200(RMIConnectionImpl.java:90)
at
javax.management.remote.rmi.RMIConnectionImpl$PrivilegedOperation.run(RMIConnectionImpl.java:1285)
at
javax.management.remote.rmi.RMIConnectionImpl.doPrivilegedOperation(RMIConnectionImpl.java:1383)
at
javax.management.remote.rmi.RMIConnectionImpl.getAttribute(RMIConnectionImpljava:619)
at sun.reflect.GeneratedMethodAccessor92.invoke(Unknown Source)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:322)
at sun.rmi.transport.Transport$1.run(Transport.java:177)
at java.security.AccessController.doPrivileged(Native Method)
at sun.rmi.transport.Transport.serviceCall(Transport.java:173)
at
sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:553)
at
sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:808)
at
sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:667)
at
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
at
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
at java.lang.Thread.run(Thread.java:636)
at
sun.rmi.transport.StreamRemoteCall.exceptionReceivedFromServer(StreamRemoteCall.java:273)
at
sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:251)
at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:160)
at com.sun.jmx.remote.internal.PRef.invoke(Unknown Source)
at
javax.management.remote.rmi.RMIConnectionImpl_Stub.getAttribute(Unknown
Source)
at
javax.management.remote.rmi.RMIConnector$RemoteMBeanServerConnection.getAttribute(RMIConnector.java:885)
at
javax.management.MBeanServerInvocationHandler.invoke(MBeanServerInvocationHandler.java:280)
... 3 more

--
Dmitri Smirnov
Y!IM: ia_slepukhin