If there are many people using SchoolTool at once, you may want to increase the number of threads to serve more users at a time.
$ sudo vim /etc/schooltool/standard/paste.ini
And set threads value:
[server:main] use = egg:zope.server host = 127.0.0.1 port = 7080 threads = 12
Default number of threads is 4.
There are alternative WSGI servers to use in place of zope.server. For development we use the Paste http server. It has different options. The important setting is threadpool_workers, default number is 10.:
[server:main] use = egg:Paste#http host = 127.0.0.1 port = 7080 threadpool_workers = 12
See Paste Thread Pool documentation for more.
NOTE: there was a thread-pool-size setting in schooltool.conf, but it does nothing. You have to add one of the options as documented above.