Hi All,
          I have built a cassandra cluster which is using property snitch file to specify my network topology to cassandra.The keyspace I have use network topology strategy.

When I tried to add new node to this cluster,I get the following error:
RROR [main] 2011-05-13 23:45:44,152 AbstractCassandraDaemon.java (line 333) Exception encountered during startup.
java.lang.NullPointerException
        at org.apache.cassandra.locator.PropertyFileSnitch.getDatacenter(PropertyFileSnitch.java:96)
        at org.apache.cassandra.locator.NetworkTopologyStrategy.calculateNaturalEndpoints(NetworkTopologyStrategy.java:87)
        at org.apache.cassandra.locator.AbstractReplicationStrategy.getAddressRanges(AbstractReplicationStrategy.java:196)
        at org.apache.cassandra.locator.AbstractReplicationStrategy.getPendingAddressRanges(AbstractReplicationStrategy.java:230)
        at org.apache.cassandra.dht.BootStrapper.getRangesWithSources(BootStrapper.java:195)
        at org.apache.cassandra.dht.BootStrapper.bootstrap(BootStrapper.java:83)
        at org.apache.cassandra.service.StorageService.bootstrap(StorageService.java:525)
        at org.apache.cassandra.service.StorageService.joinTokenRing(StorageService.java:453)
        at org.apache.cassandra.service.StorageService.initServer(StorageService.java:403)
        at org.apache.cassandra.service.AbstractCassandraDaemon.setup(AbstractCassandraDaemon.java:194)
        at org.apache.cassandra.service.AbstractCassandraDaemon.activate(AbstractCassandraDaemon.java:316)
        at org.apache.cassandra.thrift.CassandraDaemon.main(CassandraDaemon.java:79)


Please Advise.


Thanks
Anurag