I have a script at parse.com which imports a fresh information about recent videos from ~10 channels with YouTube v3 API. It worked well for some time, but about a month ago it started to fail once or twice per day with an error:
Error: can't fetch https://www.googleapis.com/youtube/v3/... "error": { "errors": [ { "domain": "usageLimits", "reason": "servingLimitExceeded", "message": "Serving Limit Exceeded" } ], "code": 403, "message": "Serving Limit Exceeded" }
As you can see from the following screenshot I use maximum 37k of 50000k units available per day. I estimate one script run could take maximum 2k units. To make absolutely sure I'm not hitting 3k units/second/user limit I've added 1 second delay before every call to YouTube API, but I still see those errors occasionally.
What's going on? Does YouTube v3 API have some other limits, for example units per IP? (one IP at Parse could host thousands of installations)