Close bad connection to solve CLOSE_WAIT stuck

[wmin0]

Somehow server side would close connection actively (timeout, server close, etc...). Therefore, client should ack close in this situation, otherwise client process will be fulled of CLOSE_WAIT and stuck finally.

[wmin0]

https://golang.org/src/database/sql/sql.go#L1045 only close errBadConn. If lib/pq doesn't close connection when set conn.bad flag, the close of the bad connection will not be called.

[domac]

https://golang.org/src/database/sql/sql.go#L1045 only close errBadConn. If lib/pq doesn't close connection when set conn.bad flag, the close of the bad connection will not be called.

I would like to ask if the repair of this code works normally and can reduce the establishment of close_wait stuck?

[wmin0]

This pr I worked with was at golang 10, you can find golang source code I referred here https://github.com/golang/go/blob/release-branch.go1.10/src/database/sql/sql.go#L1045.
And @domac your question is yes, or I don't propose this pr ._.
Maybe I should add some stress test in bench_test.go.

[domac]

This pr I worked with was at golang 10, you can find golang source code I referred here https://github.com/golang/go/blob/release-branch.go1.10/src/database/sql/sql.go#L1045.
And @domac your question is yes, or I don't propose this pr ._.
Maybe I should add some stress test in bench_test.go.

Thank you your reply.... This means that if my go version is 1.9, I need to modify it in the way of your previous pr (d6b8906) to avoid the close_wait problem?

[wmin0]

https://github.com/golang/go/blob/release-branch.go1.9/src/database/sql/sql.go#L946
In golang 1.9, the leak seems to be worse because of it only closes connection on timeout. This pr should work on it.

[wmin0]

My ci still fails because of race condition but it's not related to this pr ....
https://travis-ci.org/lib/pq/jobs/472262943

[arp242]

It seems conn.Close() is always called on ErrBadConn by database/sql? I tried to replicate this with the pqtest.Fake server, but I can't really reproduce it: conn.Close() is always called.

The logic in conn.Close() where it tries to send a Terminate message to the server is probably better than outright closing the connection?

Since this is a few years old I'll just go ahead and close it, but let me know if I'm mistaken and we can re-open.