Critical Description
KMeansDriver uses isConverged() method to determine if the k-means clustering run is complete. isConverged() has to open each SequenceFIle and read each cluster to see if the containing cluster is converged. During this process the readers are not explicitly closed, so in the case where there are a large number of sequence files opened, the driving system may run out of file handles before they are eventually implicitly reclaimed. I'm attaching a patch that explicitly closes these files as they are no longer needed to remain open.