database/sql: SetMaxOpenConns not effective

[gopherbot]

by andres.erbsen:

Thanks.

What does 'go version' print?

go version go1.2.1 linux/amd64; postgresql 9.3+146really9.1+148 on Ubuntu
go version devel +93ad232384f8 Fri Apr 11 10:11:21 2014 -0700 linux/amd64
c; postgresql 9.3.4-1 on Arch Linux
go version devel +877b2382424b Wed Apr 16 14:36:44 2014 -0700 linux/amd64; postgresql
9.3.4-1 on Arch Linux

What steps reproduce the problem?

Run http://play.golang.org/p/_o6E3COOIZ with suitable database config
 
What happened?

panic: dial tcp 127.0.0.1:5432: too many open files
OR
panic: pq: remaining connection slots are reserved for non-replication superuser

What should have happened instead?

Each db.Query should have blocked until the previous one has finished, resulting in an
infinite loop creating many many idle goroutines.

[bradfitz]

Comment 1:

Your program also consumes an infinite amount of memory in a loop, making new goroutines.
Can you fix that and verify you still see a problem?

Status changed to WaitingForReply.

[gopherbot]

Comment 2 by andres.erbsen:

Yes, the problem is still present. http://play.golang.org/p/4RnxJhgNqE

[rsc]

Comment 3:

We seem to have dropped this one.

Labels changed: added release-go1.4.

Status changed to Accepted.

[gopherbot]

Comment 4 by snoreven45:

This is pretty critical actually...

[bradfitz]

Comment 6:

I think this was a duplicate of issue #7532 and fixed by revision a6cb2adc55eb.
Please confirm.

Labels changed: added repo-main.

Status changed to WaitingForReply.

[gopherbot]

Comment 7 by andres.erbsen:

Works for me. Thanks.
go version go1.3beta2 +aecdc70c44ac Fri May 23 17:39:58 2014 -0700 linux/amd64
How I checked: http://play.golang.org/p/GuPNhxNLf7 runs in 200*0.05/4 = 2.5 seconds.

[bradfitz]

Comment 8:

Good to hear, thanks for checking!

Status changed to Duplicate.

Merged into issue #7532.