when starting cassandra, there is "Keys must be written in ascending order." error.  and, when my application reads the datastore, it throws outofmemory exception.
what causes this error?  how should I go about to fix the problem? thanks, -aj

 INFO 15:55:19,713 Creating new commitlog segment C:\dev\content\cassandra\commitlog\CommitLog-1273877719713.log
 INFO 15:55:19,822 Last written key : DecoratedKey(61078635599166706937511052402724559481:L, 61078635599166706937511052402724559481:L)
 INFO 15:55:19,822 Current key : DecoratedKey(136380791207214638541884810421800860241:Bootstrap, 136380791207214638541884810421800860241:Bootstrap)
 INFO 15:55:19,822 Writing into file C:\dev\content\cassandra\data\system\LocationInfo-tmp-10-Data.db
ERROR 15:55:20,385 Error in executor futuretask
java.util.concurrent.ExecutionException: java.io.IOException: Keys must be written in ascending order.
        at java.util.concurrent.FutureTask$Sync.innerGet(FutureTask.java:222)
        at java.util.concurrent.FutureTask.get(FutureTask.java:83)
        at org.apache.cassandra.concurrent.DebuggableThreadPoolExecutor.afterExecute(DebuggableThreadPoolExecutor.java:86)
        at org.apache.cassandra.db.CompactionManager$CompactionExecutor.afterExecute(CompactionManager.java:582)
        at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:888)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
        at java.lang.Thread.run(Thread.java:619)
Caused by: java.io.IOException: Keys must be written in ascending order.
        at org.apache.cassandra.io.SSTableWriter.beforeAppend(SSTableWriter.java:71)
        at org.apache.cassandra.io.SSTableWriter.append(SSTableWriter.java:95)
        at org.apache.cassandra.db.CompactionManager.doCompaction(CompactionManager.java:304)
        at org.apache.cassandra.db.CompactionManager$1.call(CompactionManager.java:102)
        at org.apache.cassandra.db.CompactionManager$1.call(CompactionManager.java:83)
        at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
        at java.util.concurrent.FutureTask.run(FutureTask.java:138)


--
AJ Chen, PhD
Chair, Semantic Web SIG, sdforum.org
http://web2express.org
twitter @web2express
Palo Alto, CA, USA