Intermittent timeouts on API endpoints

crates.io has returned to normal service with the processing of the download count backlog from earlier and the completion of the long running background jobs. Investigations will continue during normal hours for the crates.io team to ascertain what is causing elevated database load.

We are continuing to monitor for any further issues.

The long running background job has completed, and response times for the summary endpoint have returned to normal.

The next invocation of the relevant background job will be at 00:30 UTC (so in just under 20 minutes); we will be monitoring that closely to see if any problems resurface at that point.

We believe this issue is being caused by excess database load related to a bug fix deployed earlier today around download counting. This bug fix has caused the normal background processing of per-crate download count totals to take significantly longer and require more resources than usual.

We will shortly be temporarily disabling the summary endpoint to alleviate some of the load on the database.

(If this looks suspiciously similar to https://status.crates.io/incidents/t49v2pfpv0vl, the same issue reappeared on the summary endpoint literally within seconds of resolving that incident. C'est la vie.)

Some crates.io endpoints are timing out at present, including the summary route that drives the crates.io home page. We are investigating.