On Monday, Google's Gmail service was unavailable, but a side effect of that was somewhat unexpected; Google's Chrome browser on the desktop started crashing for many users. Users noted that a faulty interaction between the browser and Google's servers was causing the crash and made surfing the web impossible. Chromium, the open source base for the Chrome browser, was also affected.
Google Developer Tim Steele shed light on what had happened. It appears that the Chrome synchronisation service is able to set usage quotas for various data types that synchronise with it. When the problem in the Gmail system occured – a faulty load balancing configuration change is blamed – the synchronisation service switched to a "conservative" reaction mode and told all clients to throttle all data types being synchronised. Not all Chrome browsers implement all available data types though, and when told to throttle a data type it didn't implement, Chrome browsers responded by crashing.
A fix for the client has been committed upstream and the Google engineers are reviewing when it will be merged with the mainstream of Google's Chrome browser releases. The server side issues have already been resolved.