I'm having some issues with a few of my ColumnFamilies after a cassandra upgrade/import from 0.6.1 to 0.7.4.  I followed the instructions to upgrade and everything seem to work OK...until I got into the application and noticed some wierd behavior.  I was getting the following stacktrace in cassandra occassionally when I did get operations for a single subcolumn for some of the Super type CFs:

ERROR 12:56:05,669 Internal error processing get
        at org.apache.cassandra.thrift.
        at org.apache.cassandra.thrift.Cassandra$Processor$get.process(Cassandra.java:2655)
        at org.apache.cassandra.thrift.Cassandra$Processor.process(Cassandra.java:2555)
        at org.apache.cassandra.thrift.CustomTThreadPoolServer$WorkerProcess.run(CustomTThreadPoolServer.java:206)
        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)

The assertion that is failing is the check that only one column is retrieved by the get.  I did some debugging with the cli and a remote debugger and found a few interesting patterns.  First, the problem does not seem consistently duplicatable.  If one supercolumn is affected though, it will happen more frequently for subcolumns that when sorted appear at the beginning of the range.  For columns near the end of the range, it seems to be more intermittent, and almost never occurs when I step through the code line by line.  The only factor I can think of that might cause issues is that I am using custom data types for all supercolumns and columns.  I originally thought I might be reading past the end of the ByteBuffer, but I have quadrupled checked that this is not the case.

Abe Sanderson