Although many successful distributed systems have been built using RPC, we have known for a while that it's imperfect, even fundamentally flawed, because it ignores the all-too-real possibility of partial failures by attempting to make the network appear to be just another part of the local environment. A partial failure occurs in a distributed system when a remote application or the network itself fails, thereby introducing the need for applications to handle error conditions that simply cannot arise with local procedure calls. Lately, however, RPC seems to be taking even more heat than usual, mainly because of continuing advances in Web services and XML-based messaging.