Strange Broken Pipe error from Varnish health checks

[Guillaume Quintard]

Hi George,

Just to be sure, how is the probe "health" defined in your VCL?

Cheers,

-- 
Guillaume Quintard


On Mon, Apr 17, 2023 at 1:23 AM George <izghitu at gmail.com> wrote:

> Hi,
>
> I have a Varnish/nginx cluster running with varnish-7.1.2-1.el7.x86_64 on
> CentOS 7.
>
> The issue I am having comes from the varnish health checks. I am getting a
> "broken pipe" error in the nginx error log at random times like below:
> Apr 10 17:32:46 VARNISH-MASTER nginx_varnish_error: 2023/04/10 17:32:46
> [info] 17808#17808: *67626636 writev() failed (32: Broken pipe), client:
> unix:, server: _, request: "GET /varnish_check HTTP/1.1", host: "0.0.0.0"
>
> The strange thing is that this error appears only when Varnish performs
> the health checks. I have other scripts doing it(nagios, curl, wget, AWS
> ELB) but those do not show any errors. In addition to this Varnish and
> nginx where the health checks occur are on the same server and it makes no
> difference if I use a TCP connection or socket based one.
>
> Below are the varnish vcl and nginx locations for the health checks:
> backend nginx_varnish {
>                    .path = "/run/nginx/nginx.sock";
>                    .first_byte_timeout = 600s;
>                    .probe = health;
>         }
>
> location = /varnish_check {
>                 keepalive_timeout 305;
>                 return 200 'Varnish Check';
>                 access_log /var/log/nginx/varnish_check.log main;
>                 error_log /var/log/nginx/varnish_check_errors.log debug;
>                 error_log
> syslog:server=unix:/run/nginx_log.in.sock,facility=local1,tag=nginx_varnish_error,nohostname
> info;
>         }
>
> Are there any docs I can read about how exactly varnish performs the
> health checks and what internal processes are involved?
> Did anyone happen to have similar issues? This is not causing any
> operational problems for the cluster but it is just something that I want
> to determine why it is happening because it just should not be happening.
>
> Please help
> THanks in advance.
>
> _______________________________________________
> varnish-misc mailing list
> varnish-misc at varnish-cache.org
> https://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://www.varnish-cache.org/lists/pipermail/varnish-misc/attachments/20230417/ad34c346/attachment.html>