insert during forced compaction

[Jeffrey Wang]

Hey all,

I'm running 0.7.0 on a cluster of 5 machines. When I create a new column family 
after I run nodetool compact (but before it finishes), I see the error below. 
Seems like StorageService.getValidColumnFamilies() should make a copy of the 
set of column families in the case where cfNames.length == 0. Incidentally, the 
interaction of schema changes with forcing compaction/flush/etc seems like it 
could be the source of many race conditions (e.g. CF is deleted before the 
compaction gets to it). Any thoughts?

-Jeffrey

java.util.ConcurrentModificationException
        at java.util.HashMap$HashIterator.nextEntry(Unknown Source)
        at java.util.HashMap$ValueIterator.next(Unknown Source)
        at java.util.Collections$UnmodifiableCollection$1.next(Unknown Source)
        at 
org.apache.cassandra.service.StorageService.forceTableCompaction(StorageService.java:1140)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
        at java.lang.reflect.Method.invoke(Unknown Source)
        at com.sun.jmx.mbeanserver.StandardMBeanIntrospector.invokeM2(Unknown 
Source)
        at com.sun.jmx.mbeanserver.StandardMBeanIntrospector.invokeM2(Unknown 
Source)
        at com.sun.jmx.mbeanserver.MBeanIntrospector.invokeM(Unknown Source)
        at com.sun.jmx.mbeanserver.PerInterface.invoke(Unknown Source)
        at com.sun.jmx.mbeanserver.MBeanSupport.invoke(Unknown Source)
        at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(Unknown 
Source)
        at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(Unknown Source)
        at javax.management.remote.rmi.RMIConnectionImpl.doOperation(Unknown 
Source)
        at javax.management.remote.rmi.RMIConnectionImpl.access$200(Unknown 
Source)
        at 
javax.management.remote.rmi.RMIConnectionImpl$PrivilegedOperation.run(Unknown 
Source)
        at 
javax.management.remote.rmi.RMIConnectionImpl.doPrivilegedOperation(Unknown 
Source)
        at javax.management.remote.rmi.RMIConnectionImpl.invoke(Unknown Source)
        at sun.reflect.GeneratedMethodAccessor84.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
        at java.lang.reflect.Method.invoke(Unknown Source)
        at sun.rmi.server.UnicastServerRef.dispatch(Unknown Source)
        at sun.rmi.transport.Transport$1.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at sun.rmi.transport.Transport.serviceCall(Unknown Source)
        at sun.rmi.transport.tcp.TCPTransport.handleMessages(Unknown Source)
        at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(Unknown 
Source)
        at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(Unknown 
Source)
        at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown 
Source)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
        at java.lang.Thread.run(Unknown Source)