the listen queue of the daemon sockets was the default one

the listen queue of the daemon sockets was the default one

With the php default backlog a single socket of the pool queues 111
connections and then refuses: measured with a burst of 300 simultaneous
connects. The frontend gets EAGAIN on the connect and has to fall back on
another socket of the pool, or return an error.

It showed up during the load test: with 300 entries close together nginx
logged "connect() to unix:...brisk0.sock failed (11: Resource temporarily
unavailable)". With the backlog at 511 the same burst goes through entirely
and the error does not come back.

Until now the pool of ten sockets masked the problem, spreading the
connections over ten short queues instead of one long queue.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014M1jiEq9cHdE5SE5j6vFuE