add server options to set redis and cassandra in the filer and corrected filer option description text

go/weed/server.go

@@ -81,6 +81,10 @@ func init() {
 	filerOptions.dir = cmdServer.Flag.String("filer.dir", "", "directory to store meta data, default to a 'filer' sub directory of what -mdir is specified")
 	filerOptions.defaultReplicaPlacement = cmdServer.Flag.String("filer.defaultReplicaPlacement", "", "Default replication type if not specified during runtime.")
 	filerOptions.redirectOnRead = cmdServer.Flag.Bool("filer.redirectOnRead", false, "whether proxy or redirect to volume server during file GET request")
+	filerOptions.cassandra_server = cmdFiler.Flag.String("filer.cassandra.server", "", "host[:port] of the cassandra server")
+	filerOptions.cassandra_keyspace = cmdFiler.Flag.String("filer.cassandra.keyspace", "seaweed", "keyspace of the cassandra server")
+	filerOptions.redis_server = cmdServer.Flag.String("filer.redis.server", "", "host:port of the redis server, e.g., 127.0.0.1:6379")
+	filerOptions.redis_database = cmdFiler.Flag.Int("filer.redis.database", 0, "the database on the redis server")
 
 }