Necessary database migrations for this commit:
alter table servers add column log_blacklist bigint[] not null default array[]::bigint[];
alter table servers add column blacklist bigint[] not null default array[]::bigint[];
Instead of acquiring a connection per service per request, we
acquire connections more often but at a more granular level, meaning
they're also disposed of more quickly instead of staying for a long time
in case of long-running commands or leaks.
