In Azure there is a thread-problem with rules

[speyburner]

We used rules for a while and it worked well. Now we moved with our project into the cloud and we encountered problems with rules. It seems that they are not thread safe. It's a tricky problem, because it only happens on production, where we have a lot of concurrent threads in different languages.

Is it already a known bug? Maybe it is a problem with Sitecore rules engine.