clarify "No other nodes seen! Unable to bootstrap" error message

patch by jbellis; reviewed by slebresne for CASSANDRA-3191

git-svn-id: https://svn.apache.org/repos/asf/cassandra/branches/cassandra-1.0.0@1170257 13f79535-47bb-0310-9956-ffa450edef68

conf/cassandra.yaml

@@ -84,8 +84,8 @@ saved_caches_directory: /var/lib/cassandra/saved_caches
 commitlog_sync: periodic
 commitlog_sync_period_in_ms: 10000
 
-# any class that implements the SeedProvider interface and has a constructor that takes a Map<String, String> of
-# parameters will do.
+# any class that implements the SeedProvider interface and has a
+# constructor that takes a Map<String, String> of parameters will do.
 seed_provider:
     # Addresses of hosts that are deemed contact points. 
     # Cassandra nodes use this list of hosts to find each other and learn

src/java/org/apache/cassandra/dht/BootStrapper.java

@@ -165,7 +165,12 @@ public class BootStrapper
         }
 
         if (endpoints.isEmpty())
-            throw new RuntimeException("No other nodes seen!  Unable to bootstrap");
+            throw new RuntimeException("No other nodes seen!  Unable to bootstrap."
+                                       + "If you intended to start a single-node cluster, you should make sure "
+                                       + "your broadcast_address (or listen_address) is listed as a seed.  "
+                                       + "Otherwise, you need to determine why the seed being contacted "
+                                       + "has no knowledge of the rest of the cluster.  Usually, this can be solved "
+                                       + "by giving all nodes the same seed list.");
         Collections.sort(endpoints, new Comparator<InetAddress>()
         {
             public int compare(InetAddress ia1, InetAddress ia2)

src/java/org/apache/cassandra/service/AbstractCassandraDaemon.java

@@ -346,15 +346,15 @@ public abstract class AbstractCassandraDaemon implements CassandraDaemon
             }
             
             start();
-        } catch (Throwable e)
+        }
+        catch (Throwable e)
         {
-            String msg = "Exception encountered during startup.";
-            logger.error(msg, e);
+            logger.error("Exception encountered during startup", e);
             
             // try to warn user on stdout too, if we haven't already detached
-            System.out.println(msg);
             e.printStackTrace();
-            
+            System.out.println("Exception encountered during startup: " + e.getMessage());
+
             System.exit(3);
         }
     }