[plt-scheme] Some rough PLT web app figures

From: Matthias Felleisen (matthias at ccs.neu.edu)
Date: Wed Nov 19 21:09:49 EST 2008

This really neat! We should send you to DC to tell NSF about the  
success of our web and scheme stuff in general. -- Matthias

On Nov 19, 2008, at 8:41 PM, Michael Forster wrote:

> Hi,
> Given some of the recent blog posts on use of the PLT web server,
> I thought I would share some of our deployment figures.  Sorry that
> it's little more than a quick laundry list; time and customer  
> permitting,
> perhaps I'll write a more thorough summary later.
> We've written 5 PLT-based web apps for one of our clients.  One
> provides core personnel scheduling, work order, billing, and payroll
> operations; the other four provide remote data entry for various
> business processes built around the core (e.g. employee time-keeping).
> Together, the apps weigh in at 24286 LOC of Scheme code, of which
> 6340 LOC is shared as libraries.  The business rules and data are
> modeled exclusively and stored using PostgreSQL.  The 'view' layer
> is written in Scheme as is a custom date/time library required for
> multiple time-zone business logic.
> We run each app under a separate mzscheme instance, all behind
> an Apache reverse proxy to provide SSL.  The core app hovers
> around 300M memory usage, of which about 250M is resident.  The
> others consume between 60 and 160M each.
> Here's the hardware and software:
> Dell PE 2970
> 2GHz Quad Core AMD Opteron
> 8G RAM
> FreeBSD 7.0-RELEASE amd64
> PostgreSQL 8.2
> mz-4.1
> spgsql
> instaservlet
> custom servlet-shim.ss:
> LRU memory manager
> 1G memory threshold
> 5 second check
> 24 life points
> 30 minute period for life point deduction
> Hope of that's of use to someone.
> Cheers!
> Mike
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