Using XML in Performance Sensitive Apps?
A Parser's Baggage queries: "For the last couple of years I've been working with XML based protocols and one thing that keeps coming up is the amount of CPU power needed to handle 10, 20, 30 or 40 concurrent requests. I've ran benchmarks on both Java and C#, and my results show that on a 2ghz CPU, the upper boundary for concurrent clients is around 20, regardless of the platform. How have other developers dealt with these issues and what kinds of argument do you use to make the performance concerns know to the execs. I'm in favor of using XML for it's flexibility, but for performance sensitive applications, the weight is simply too big. This is especially true when some executive expects and demands that it handle 1000 requests/second on a 1 or 2 cpu server. Things like stream/pull parsers help for SOAP, but when you're reading and using the entire message, pull parsing doesn't buy you any advantages."
1. I use DOM objects, in this case the MSXML free threaded model, to handle xml strings and read out the string only at the last point.
2. I would also suggest using wstring/string in the STL library as you can reserve string buffers in advance in case you have to handle the XML as strings, that's if your using c++, don't know much about c#/java sorry.
using this method I have manage to push it to ~200 concurrent requests.
mlati