We mostly used simpler RPC mechanisms like XMLRPC or REST. But cross-language calls (other than client-server) were really the exception. Probably the only real

We mostly used simpler RPC mechanisms like XMLRPC or REST. But cross-language calls (other than client-server) were really the exception. Probably the only really performance sensitive ones were to our SOLR-based search. Yes, you can easily move chunks of the address space around, but we decided that the pain that results from remapping (like when you add a new machine) is worse. We very rarely had a problem with our master (which we ran in master-master replication, how's that for term overloading). The few exceptions were times that our own bad code ran amok driving load. It was way better to invest in an automatic query killer.