All,

 In 0.8.6 I got myself into a bit of a fix. First I tried to drop a column family. This failed because I didn't have JNA installed (known and documented). To fix this I drained the node, stopped the process, installed JNA, and restarted C*. 

Unfortunately this lead to an inconsistency in schema versions. Apparently the schema was successfully modified locally during the drop command even though the snapshot failed. In system.log HH then began to fail:

ERROR [HintedHandoff:4] 2011-11-10 19:24:35,628 AbstractCassandraDaemon.java (line 139) Fatal exception in thread Thread[HintedHandoff:4,1,main]
java.lang.RuntimeException: java.lang.RuntimeException: Could not reach schema agreement with /10.252.229.235 in 60000ms
        at org.apache.cassandra.utils.WrappedRunnable.run(WrappedRunnable.java:34)
        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)
Caused by: java.lang.RuntimeException: Could not reach schema agreement with /10.252.229.235 in 60000ms
        at org.apache.cassandra.db.HintedHandOffManager.waitForSchemaAgreement(HintedHandOffManager.java:293)
        at org.apache.cassandra.db.HintedHandOffManager.deliverHintsToEndpoint(HintedHandOffManager.java:304)
        at org.apache.cassandra.db.HintedHandOffManager.access$100(HintedHandOffManager.java:89)
        at org.apache.cassandra.db.HintedHandOffManager$2.runMayThrow(HintedHandOffManager.java:397)
        at org.apache.cassandra.utils.WrappedRunnable.run(WrappedRunnable.java:30)



This edge case might be prevented if the schema was updated as the final step of a DROP. 

Thoughts on if this is worth submitting as a bug?

Ian