As of #4027, we require psutil to be installed, so it should be in our
dependency list. We can also remove some of the conditional import code
introduced by #992.
Fixes#4062.
symlinks apparently break setuptools on python3 and alpine
(https://bugs.python.org/issue31940), so let's stop using a symlink and just
use the file directly.
ExpiringCache required that `start()` be called before it would actually
start expiring entries. A number of places didn't do that.
This PR removes `start` from ExpiringCache, and automatically starts
backround reaping process on creation instead.
We should explicitly close any db connections we open, because failing to do so
can block other transactions as per
https://github.com/matrix-org/synapse/issues/3682.
Let's also try to factor out some of the boilerplate by having server classes
define their datastore class rather than duplicating the whole of `setup`.
Turns out that the user directory handling is fairly racey as a bunch
of stuff assumes that the processing happens on master, which it doesn't
when there is a synapse.app.user_dir worker. So lets just call the
function directly until we actually get round to fixing it, since it
doesn't make the situation any worse.
Run the handlers for replication commands as background processes. This should
improve the visibility in our metrics, and reduce the number of "running db
transaction from sentinel context" warnings.
Ideally it means converting the things that fire off deferreds into the night
into things that actually return a Deferred when they are done. I've made a bit
of a stab at this, but it will probably be leaky.
First of all, avoid resetting the logcontext before running the pushers, to fix
the "Starting db txn 'get_all_updated_receipts' from sentinel context" warning.
Instead, give them their own "background process" logcontexts.
