Metrics cannot be read at the moment because of an issue with the index components.
A chunk and its replica are both non-responding which means the service as a whole is unavailable. We are working on it.
10:00 UTC: An index node being unavailable threw us off on the wrong track. Its replica was actually working just fine, the issue was with both front read nodes being stuck at the same time. We will improve monitoring and try to figure out what went wrong and why.