avoid trying to watch cassandra-topology.properties when loaded from jar

patch by Mck SembWever; reviewed by jbellis for CASSANDRA-3138

git-svn-id: https://svn.apache.org/repos/asf/cassandra/branches/cassandra-0.8@1165405 13f79535-47bb-0310-9956-ffa450edef68

CHANGES.txt

@@ -1,3 +1,8 @@
+0.8.6
+ * avoid trying to watch cassandra-topology.properties when loaded from jar
+   (CASSANDRA-3138)
+
+
 0.8.5
  * fix NPE when encryption_options is unspecified (CASSANDRA-3007)
  * include column name in validation failure exceptions (CASSANDRA-2849)

src/java/org/apache/cassandra/locator/PropertyFileSnitch.java

@@ -58,14 +58,22 @@ public class PropertyFileSnitch extends AbstractNetworkTopologySnitch
     public PropertyFileSnitch() throws ConfigurationException
     {
         reloadConfiguration();
-        Runnable runnable = new WrappedRunnable()
+        try
         {
-            protected void runMayThrow() throws ConfigurationException
+            FBUtilities.resourceToFile(RACK_PROPERTY_FILENAME);
+            Runnable runnable = new WrappedRunnable()
             {
-                reloadConfiguration();
-            }
-        };
-        ResourceWatcher.watch(RACK_PROPERTY_FILENAME, runnable, 60 * 1000);
+                protected void runMayThrow() throws ConfigurationException
+                {
+                    reloadConfiguration();
+                }
+            };
+            ResourceWatcher.watch(RACK_PROPERTY_FILENAME, runnable, 60 * 1000);
+        }
+        catch (ConfigurationException ex)
+        {
+            logger.debug(RACK_PROPERTY_FILENAME + " found, but does not look like a plain file. Will not watch it for changes");
+        }
     }
 
     /**