Comment by ChuckMcM

Nice catch. A long time ago the services on the backend were killed by a special URL. And someone found it, and it wasn't filtered by the front end. And of course someone tried to use it, but it never returns since it kills the service, but their client retried ... it was a lot of "what the heck is happening" going on until SRE figured it out and then they immediately patched the front end and the anomalies stopped. It is too bad the person who caused it didn't file for a bug bounty like this person did, they probably would have had something to show for their efforts besides "hey look at this funny thing you can do, oh wait it doesn't do it any more."