Rate Limiting#

This plugin allows instructors to limit the number of times students can submit to the autograder in any given window to prevent students from using the AG as an “oracle”. This plugin has a required configuration allowed_submissions, the number of submissions allowed during the window, and accepts optional configurations weeks, days, hours, minutes, seconds, milliseconds, and microseconds (all defaulting to 0) to configure the size of the window. For example, to specify 5 allowed submissions per-day in your otter_config.json:

    "plugins": [
            "otter.plugins.builtin.RateLimiting": {
                "allowed_submissions": 5,
                "days": 1

When a student submits, the window is caculated as a datetime.timedelta object and if the student has at least allowed_submissions in that window, the submission’s results are hidden and the student is only shown a message; from the example above:

You have exceeded the rate limit for the autograder. Students are allowed 5 submissions every 1

The results of submission execution are still visible to instructors.

If the student’s submission is allowed based on the rate limit, the plugin outputs a message in the plugin report; from the example above:

Students are allowed 5 submissions every 1 days. You have {number of previous submissions}
submissions in that period.

otter.plugins.builtin.RateLimiting Reference#

The actions taken by at hook for this plugin are detailed below.