I restarted restbase on deployment-restbase0{1,2} with systemctl restart restbase, which worked.

We did deploy a config change that enabled commons last night, which in turn auto-created new tables. It's possible that something went wrong during concurrent table creation, which would potentially have left one or two workers in an unhappy state (which is tracked in T98934).

I was not able to reproduce the error after this, so I assume that things are okay now.

yeah, It is still occurring .

@Ryasmeen, which article is this happening with?

@GWicke: In any page in Betalabs, you can try this one: http://en.wikipedia.beta.wmflabs.org/wiki/User:RYasmeen_%28WMF%29