Guides

Local service problems on macOS, one problem per page. Terminal fix first, ServeMon at the end.

• Check whether Postgres is running on a Mac

  Four ways to tell whether PostgreSQL is actually up on macOS: pg_isready, brew services list and info, lsof on port 5432, and docker ps, plus why a running process is not the same as a server that answers.

• brew services says started but the service is not running

  Why brew services list reports started while Postgres, Redis, or MySQL refuses connections: how to read the service log, check launchd's exit code, clear a stale pid file, and fix a broken plist.

• Where the Postgres data directory is on a Mac

  Where Homebrew, Postgres.app, and Docker keep the PostgreSQL data directory, postgresql.conf, and the log, and the SHOW commands that make the running server tell you.

• Could not connect to Redis at 127.0.0.1:6379: Connection refused

  Check with redis-cli ping, start the Homebrew service, read redis.log, check bind and port in redis.conf, and publish the port if Redis is in Docker.

• Can't connect to local MySQL server through socket vs TCP on 3306

  localhost means the socket, 127.0.0.1 means TCP, Docker has no host socket, and how to check each.

• Homebrew Postgres and a Docker container both on 5432

  How to see which one owns the port, why psql and your app can hit different databases, and how to stop one or move the container to 5433.

• Which local service is Docker, Homebrew, or a bare binary

  Read the process behind the port with lsof and ps, match its path to Homebrew's Cellar or Postgres.app, check docker ps for containers, and compare with brew services list.

Something missing? Email [email protected] with the error you hit.