[Ur] Performance of Ur/Web in a live site

[Adam Chlipala]

Chris Double wrote:
> I rewrote an existing web application of mine in Ur/Web last weekend
> to see how it performed vs the current one. [...]
>
> The original pool server I wrote in another language struggled at
> about 20 work requests per second. Once it hit 30 it would peg the
> server at 100% CPU and eventually fall over. The Ur/Web version has
> hit 70 work requests per second and averages 40-50. This is using very
> low CPU and looks to be able to scale higher quite nicely. Previously
> the dealing with the web requests was the bottleneck. With this
> version it's mainly the database that's using more of the CPU. Ur/Web
> sits with very low memory and handles it fine.
>    

This is great news!  Is this application open source?  Would you mind 
saying which language/framework you used for the prior version?

Have you done any concurrency scaling performance comparison of the two 
versions?  Especially with Postgres as the database backend, I wouldn't 
be surprised if the Ur/Web version scales better, too, as you increase 
the number of threads (via the "-t" command-line parameter to the 
application).