Beginner’s guide to exponential backoff in Google Apps Script for handling rate limit errors

Exponential Backoff, a process by which when something fails you try again a set number of times whilst increasing the delay between each attempt.

Sample Apps Script code for Exponential Backoff

The following Google Apps Script is designed to explore Exponential Backoff – a process by which when something fails you try again a set number of times whilst increasing the delay between each attempt, up to a certain point.

I needed this for a tool I built which adds Guests to a Calendar event from a Google Form submission. Whilst I was using ScriptLock to prevent simultaneous submissions, the code ran so fast that it would infrequently trip the Calendar API with the following error message “API call to calendar.events.patch failed with error: Rate Limit Exceeded”.

By infrequently I mean a reported issue only once in 3,500 submissions over the course of 12 months. Enough however to take the opportunity to learn about Exponential Backoff and to squash that single instance.

Just a note that this is one way to implement it.

Source: The Gift of Script: Exponential Backoff