+EXIT_NODESETUP_ERROR = 12
+EXIT_CONFIRMATION = 13 # need user confirmation
+
+# tags
+TAG_CLUSTER = "cluster"
+TAG_NODE = "node"
+TAG_INSTANCE = "instance"
+MAX_TAG_LEN = 128
+MAX_TAGS_PER_OBJ = 4096
+
+# others
+DEFAULT_BRIDGE = "xen-br0"
+SYNC_SPEED = 30 * 1024
+LOCALHOST_IP_ADDRESS="127.0.0.1"
+TCP_PING_TIMEOUT = 10