massive numbers of threads with name that includes commitScheduler

[Schwartz, Tony]

>From time to time I see massive number of threads that have commitScheduler in 
>the name of the thread.  When this happens, solr is pegging the disk IO and 
>querying becomes unusable for a while.  I have many collections (240 shards).  
>It happens once in a while, I'm really not sure what is causing it or how to 
>prevent it.  Any thoughts on where I can look?  I have set the mergeScheduler 
>as such:

       <mergeScheduler class="org.apache.lucene.index.ConcurrentMergeScheduler">
                <int name="maxMergeCount">6</int>
                <int name="maxThreadCount">1</int>
        </mergeScheduler>

Thank you!

Tony Schwartz