SSL_write() failed errors

[Maxim Dounin]

Hello!

On Fri, Jul 19, 2019 at 11:35:44AM -0700, Palvelin Postmaster via nginx wrote:

> > On 19 Jul 2019, at 9.59, Maxim Dounin <mdounin at mdounin.ru> wrote:
> > 
> > Hello!
> > 
> > On Thu, Jul 18, 2019 at 10:03:24AM -0700, Palvelin Postmaster via nginx wrote:
> > 
> >> we’re getting random SSL_write() failed errors on seemingly 
> >> legitimate requests. The common denominator seems to be they are 
> >> all for static files (images, js, etc.). 
> >> 
> >> Can anyone help me debug the issue?
> >> 
> >> Here’s a debug log paste for one incident: 
> >> https://pastebin.com/ZsbLuD5N
> >> 
> >> Our architecture is: Amazon ALB > Nginx 1.14 > PHP-FPM 7.3
> > 
> > The following debug log:
> > 
> > 2019/07/18 19:27:25 [debug] 1840#1840: *2037 SSL_write: -1
> > 2019/07/18 19:27:25 [debug] 1840#1840: *2037 SSL_get_error: 6
> > 2019/07/18 19:27:25 [crit] 1840#1840: *2037 SSL_write() failed (SSL:) while sending response to client...
> > 
> > suggests that this is due to error 6, that is, 
> > SSL_ERROR_ZERO_RETURN.  This looks strange, as we haven't seen 
> > this error being returned from SSL_write(), but might be 
> > legitimate.  In theory this can happen if nginx got a close notify 
> > SSL alert while writing a response, and probably have something to 
> > do with Amazon ALB before nginx.
> > 
> > Just in case, could you please provide details about OpenSSL 
> > library you are using ("nginx -V" should contain enough details)?
> 
> Certainly:
> 
> nginx version: nginx/1.14.0 (Ubuntu)
> built with OpenSSL 1.1.0g  2 Nov 2017 (running with OpenSSL 1.1.1c  28 May 2019)

You are using Ubuntu 18.04 package, correct?

Could you please update to the latest package (1.14.0-0ubuntu1.3, 
exactly the same nginx version rebuild against OpenSSL 1.1.1c) and 
report if it fixes the errors in question or not?

-- 
Maxim Dounin
http://mdounin.ru/