CLA check failed - "Error: The service is currently unavailable."

[OmarShehata]

The CLA check failed today here CesiumGS/cesium#9147 (comment) with the following error:

Error: The service is currently unavailable.

I believe this is an error returned from the Google Sheets API.

[OmarShehata]

It may just be a fluke because the CLA check is working again now: CesiumGS/cesium#9148 (comment). Not sure if there's any other action that can be taken here other than making the error thrown more description, like, prefixing it with "Failed while trying to fetch individual CLA google sheet" or something.

[mramato]

Do we retry on a failed request? or do we just try once and give up? Almost all kinds of network communication like this uses a retry/exponential backoff strategy.

[OmarShehata]

We do not currently retry on CLA failure: https://github.com/CesiumGS/cesium-concierge/blob/master/lib/commentOnOpenedPullRequest.js#L165.

This just happened again here: CesiumGS/cesium#9161 (comment). It should be easy to add a retry after 1 second, 2 second, 4 etc and give up after X attempts.

[ptrgags]

Noticing this again here: CesiumGS/cesium#9826 (comment) -- talking with @lilleyse we think this one was also probably a fluke, perhaps network related

CC @ebogo1