public int countStoreFiles() {
      int count = 0;
      for (HStore store : stores.values()) {
        count += store.getStorefilesCount();
      }
      return count;
    }
Test for the case where a regionserver going down has enough cycles to do damage to regions that
have actually been assigned elsehwere.
<p>
If we happen to assign a region before it fully done with in its old location -- i.e. it is on
two servers at the same time -- all can work fine until the case where the region on the dying
server decides to compact or otherwise change the region file set. The region in its new location
will then get a surprise when it tries to do something w/ a file removed by the region in its old
location on dying server.
<p>
Making a test for this case is a little tough in that even if a file is deleted up on the
namenode, if the file was opened before the delete, it will continue to let reads happen until
something changes the state of cached blocks in the dfsclient that was already open (a block from
the deleted file is cleaned from the datanode by NN).
<p>
What we will do below is do an explicit check for existence on the files listed in the region
that has had some files removed because of a compaction. This sort of hurry's along and makes
certain what is a chance occurance.
hbase-server/src/test/java/org/apache/hadoop/hbase/TestIOFencing.java