Public bug reported:

I am seeing concurrency issues when using mailman 3 in a threaded application server.

Reading the Storm documentation it states that "Store objects are not threadsafe. [...] Therefore, the best policy is usually to create a Store object for each thread which needs one" (https://storm.canonical.com/Manual#Working_with_multiple_threads)

In mailman/database/base.py:141 I see a Store being created and cached.

As recommended in the storm docs, Stores should not be cached.

** Affects: mailman Importance: Undecided Status: New