通过Docker SSH隧道进入lang服务和PostgreSQL

I have got a resources release problem.

1. PostgreSQL runs on a server 1.
2. Go lang service runs on a server 2 in a Docker container.
3. There is an ssh tunnel Docker container for a connection between the database and the service. It does not know anything except ssh.

Docker is in swarm mode.

The service (2) connects to the database via golang database/sql library. I call sql.Open(), driverName = "postgres". Then everything is ok. In some time, may be in 30 minutes, (*DB) Query() returns an error read: connection reset by peer. If I call (*DB) Ping() previously, Ping() does not return an error, but the next call Query() does.

If I call Query() again in some time, a new connection is created. I can see it in a select * from pg_stat_activity; query in the database (state = idle). But the previous connection has not been removed.

So I call (*DB) Close(), create a new DB object and call sql.Open().

Close closes the database, releasing any open resources.

(https://golang.org/pkg/database/sql/#Conn.Close)

But after the Close call I can still see the connection in a select * from pg_stat_activity; query in the database (state = idle). I see the bad connection and the new one.

As the result there is a resources leak.

What is the correct way to handle a read: connection reset by peer error? Why have I got this error?