class size

class size

by Holly Carley -
Number of replies: 1
We (at Rutgers) are planning on upgrading to to the newest version of WeBWorK. We will also be upgrading to a much more powerful machine. We had problems in the past (2004) trying to fit about 1600+ students in one single course (the system was too slow? or the database not efficient enough?). We had to split them up into many courses for the system to handle things well. Has anything changed in the new version that would eliminate this problem? I was wondering if any advice could be offered on whether we should try this again with the newest WeBWorK?

Here are some of the specs of the new machine:
2x Dual Core AMD Opteron™ 8212, 2.0GHz,2x1Mb Cache,1Ghz HyperTransport

Memory: 16GB Memory, 8x2GB, 667MHz, Dual Ranked DIMMs : 16G8D6D [311-6430]

Will run Debian.

Also, here are some questions from the system administrator:

"Has any performance testing done with the dual and quad core
processors been done? Have you coded anything for 64-bit systems?

Is there are any suggestions or preferences with the OSes.
We were working on new installs of centos 5 but have a lot of
systems still running fc5 and will be testing on both fc6 and centos
this summer. The current install is debian. "
In reply to Holly Carley

Re: class size

by Gavin LaRose -
Hi Holly,

At the University of Michigan we're running similar numbers of students as are you; in the Fall we have one class of 1500, plus classes of 700 and 800 running simultaneously on our server. For reasons other than performance we have the course of 1500 split into sections, but all sections have the same deadlines. If the performance issue is the size of the mySQL tables, our experience won't be directly relevant to yours, but I would be surprised if that were the bottleneck. Sam or Mike may have insight on that particular issue, as they've spent more time looking at where the code slows down.

We run WeBWorK (and all of our other instructional technology applications) on a 4 dual core Xeon 2.8GHz system with 12GB memory, running RHEL. We've had no performance issues other than when we had MaxRequestsPerChild set too high in the apache configuration (which caused the apache child processes to quietly slurp up memory until they used up all 12GB, which resulted in everything grinding to a halt). This is 64bit, but I don't know if any specific work has been done to take full advantage of that.

My bet is that a server load of any Linux distribution will work fine to run WeBWorK. We've used RHEL and SUSE, as well as Solaris before we converted to Linux, all with no trouble.