What are the specific quotas for Properties Service in Google Apps for an Add-On?

Question

We have an Add-On that uses DocumentProperties and UserProperties for persistence. We've recently had some users complain about receiving the error: "Service invoked too many times for one day: properties". I spent some time optimizing usage of the Properties Service when developing the Add-On to ensure this doesn't happen, but it still seems to in some situations.

According to https://developers.google.com/apps-script/guides/services/quotas, there is a quota of 50,000 "set" calls per day per user or document. There does not appear to be a limit on the number of reads.

Here's how our app utilizes properties:

• We only set properties when values change. Even with very heavy usage, I still can't imagine more than 500 property "set" calls per day per user. When we set properties, we also write to the Cache Service with a 6 hour timeout.

• We read the properties when the user is using the add-on, and also every 10 seconds while the add-on is idling. That comes out to 8640 reads per document per day. However, we use the Cache Service for reads, so very few of those reads should hit the Properties Service. I did discover a bug that existed when the most recent bug report came in where we don't re-write to the Cache even after it expires until an explicit change is made. By my calculations, that leads to 6 hours with 1 read, and then 18 hours of 6 reads/min * 60 min/hr, or 6480 reads. Factor in some very heavy usage, and we're still at about 7000 reads per day per document. The user claims he had two copies of the document open, so 14000 reads. That's still far below the 50000 quota, not to mention that the quota seems to be for setting properties, not reading them.

Would anyone from Google be able to offer some insight into any limits on Properties reads, or give any advice on how to avoid this situation going forward?

Thanks much!

Answer 1

This 50,000 writes per day quota is shared across all the scripts. This means that if a particular script makes heavy use of writes, it could negatively impact other scripts that are installed by the same user.