When using Ruby Gem pg and establish database connections to a PostgreSQL database, you’ll see PG errors when the database connection becomes problematic. In my experience, two typical PG errors are PG::AdminShutdown and PG::UnableToSend.

Error PG::AdminShutdown

The error message contains the following information:

FATAL: terminating connection due to administrator command (PG::AdminShutdown) server closed the connection unexpectedly This probably means the server terminated abnormally before or while processing the request.

The PG::AdminShutdown error could be caused by database server receiving SIGTERM/SIGINT/SIGQUIT or kill command on the connection process. Each system signal shut down server processes in different manners, see the pgadmin document to know the details.

When you hit the PG::AdminShutdown error, you’ll like to check if the database server gets restarted and if the server resumes to the normal state.

Error PG::UnabletoSend

The error message looks like:

server closed the connection unexpectedly (PG::UnableToSend) This probably means the server terminated abnormally before or while processing the request.

The PG::UnabletoSend error usually means a connection timeout or network issue. It could be a temporary issue though. You can check if the other connections to the database server work well or not.