Since today (ie https://grafana.wikimedia.org/dashboard/db/service-cxserver?orgId=1&from=1543257000000&to=1543312725861), Apertium MT API requests with V2 endpoint was too high. Investigate and find the root cause.
I 've helped with the debugging. Starting from apertium it was clear something automated was POSTing a lot of requests to it. It turned out they were mostly for the rus|bel langpair but that was a red herring as it was just the snapshot in time I looked at. Moving from apertium to cxserver it became clear something was POSTing to /v2/translate endpoint. The things I noted were mostly about another language pair ca|oc but again that was a snapshot in time. Then a VM IP caught my eye, one that was of wcdo.wcdo.eqiad.wmflabs. I 've jumped into said VM and stopped a process that was clearly heavily hitting the cxserver API
@marcmiquel as I understand it this was your process. I am really sorry I had to stop your stats generation, I hope I did not cause much damage, but it was causing stress to the API (~700 requests per second). This was 2 orders of magnitude more than the standard traffic and was deemed excessive. Also there was no clear User-Agent header in the requests, which would have helped more in identifying the requester and notifying you accordingly. Please have a look at https://www.mediawiki.org/wiki/API:Etiquette if you haven't already.
Thanks for the message akosiaris. I'm sorry the posts were heavy. This process runs only once a month.
I will concentrate text in longer queries. What is the text length limit for a single query?