1. XML-RPC: How Fast ? Brent Callaghan Sun Microsystems, Inc.

2. My Background Experience with ONC RPC protocols Participant in ONCRPC WG @ IETF. NFS: high performance, kernel-based NFS version 4 uses ONC RPC over the Internet.

3. XML for Data Marshalling Everything is text: Jane 3 Convenient for text-oriented transports, e.g. SMTP, HTTP Readable by humans (great when debugging) Covenient if data already described by XML

4. XML for Data Marshalling Tags and ASCII make it fat w.r.t binary protocols like XDR. –Needs approx twice as many bytes. Binary args or results need Base64 encoding (as text) –Significant effect on modem or wireless links. Text takes time to parse –More CPU instructions per transaction implies more CPUs for a given level of service.

5. HTTP as a Bottleneck Verbose HTTP headers on every call: POST /StockQuote HTTP/1.1 Host: www.stockquoteserver.com Content-type: text/xml Content-Length: 1094

6. HTTP as a Bottleneck Calls funnel through web server on port 80. RPC service needs to be in web server address space. Port 80 Fork/exec RPC Server RPC Server HTTP Server RPC Server Port 1234 RPC Server Direct Connect

7. Conclusion Don’t use XML-RPC for performance-critical apps..