Where the action is against two or more defendants, and the summons is served on one or more but not on all of them, the plaintiff may proceed as follows:
1. If the action be against the defendants jointly indebted upon a contract, the plaintiff may proceed against the defendant served, unless the court otherwise directs; and if the plaintiff recover judgment, it may be entered against all the defendants thus jointly indebted, so far only as that it may be enforced against the joint property of all and the separate property of the defendant served; or
2. If the action be against defendants severally liable, the plaintiff may proceed against the defendants served in the same manner as if they were the only defendants.