Allow removing LocationInfo sstables (to allow cluster rename)

patch by amorton; reviewed by slebresne for CASSANDRA-2632


git-svn-id: https://svn.apache.org/repos/asf/cassandra/branches/cassandra-0.7@1101792 13f79535-47bb-0310-9956-ffa450edef68

CHANGES.txt

@@ -17,6 +17,7 @@
  * Don't allow {LOCAL|EACH}_QUORUM unless strategy is NTS (CASSANDRA-2627)
  * Fix regression where bootstrapping a node with no schema fails
    (CASSANDRA-2625)
+ * Allow removing LocationInfo sstables (CASSANDRA-2632)
 
 
 0.7.5

src/java/org/apache/cassandra/db/SystemTable.java

@@ -221,18 +221,9 @@ public static void checkHealth() throws ConfigurationException, IOException
         if (cf == null)
         {
             // this is either a brand new node (there will be no files), or the partitioner was changed from RP to OPP.
-            for (String path : DatabaseDescriptor.getAllDataFileLocationsForTable("system"))
-            {
-                File[] dbContents = new File(path).listFiles(new FilenameFilter()
-                {
-                    public boolean accept(File dir, String name)
-                    {
-                        return name.endsWith(".db");
-                    }
-                }); 
-                if (dbContents.length > 0)
-                    throw new ConfigurationException("Found system table files, but they couldn't be loaded. Did you change the partitioner?");
-            }
+            ColumnFamilyStore cfs = table.getColumnFamilyStore(STATUS_CF);
+            if (!cfs.getSSTables().isEmpty())
+                throw new ConfigurationException("Found system table files, but they couldn't be loaded. Did you change the partitioner?");
 
             // no system files.  this is a new node.
             RowMutation rm = new RowMutation(Table.SYSTEM_TABLE, LOCATION_KEY);