Welcome! Log In Create A New Profile

Advanced

Re: nginx upstream problem

Maxim Dounin
April 13, 2010 06:10PM
Hello!

On Tue, Apr 13, 2010 at 04:28:35PM -0400, izghitu wrote:

[...]

> worker_processes 32;

This looks a bit too many.

[...]

> include /etc/nginx/conf.d/*.conf;

Do you have only one file there? Note that upstream{} blocks are
all defined in http section, and having two with identical names
are likely to cause confusion.

[...]

> upstream cloud {
> server apache3 max_fails=1 fail_timeout=5;
> server apache2 max_fails=1 fail_timeout=5;
> server apache1 max_fails=1 fail_timeout=5;
> }

[...]

> proxy_read_timeout 30;
> proxy_next_upstream error timeout;
> proxy_pass http://cloud;

[...]

> Problem 1:
> Regardless of the order of the apache servers in the upstream,
> apache3 most of the time gets the lowest traffic. Sometimes it
> gets the same, sometimes it gets very few traffic.

Does these servers (apache1, apache2, apache3) actually resolve
to distinct ip addresses?

> Problem 2:
> If I take down one apache server(halt or /etc/init.d/network
> stop) then I can see from the error log of nginx that it is
> still sending traffic to that apache server and I see time out
> or no route to host errors. When browsing the website I get
> waiting pages all the time which proves it tries to send to the
> apache server that is down.

nginx marks server as "down" after "max_fails" failures in
"fail_timeout" seconds, and re-enables it again after
"fail_timeout" seconds.

As it takes 60 seconds (default proxy_connect_timeout) to detect
that server is down, and you switch it off only for 5 seconds -
it's somewhat expected that nginx will try to use dead server most
of the time.

Also note that statuses of upstream servers are tracked
independantly by each worker (so with 32 workers you are likely to
see dead server used all the time by different workers).

You may tune nginx to behave a bit better by setting bigger
fail_timeout and/or smaller proxy_connect_timeout.

[...]

Maxim Dounin

_______________________________________________
nginx mailing list
nginx@nginx.org
http://nginx.org/mailman/listinfo/nginx
Subject Author Posted

nginx upstream problem

izghitu April 13, 2010 04:28PM

Re: nginx upstream problem

Maxim Dounin April 13, 2010 06:10PM

Re: nginx upstream problem

izghitu April 13, 2010 06:19PM

Re: nginx upstream problem

izghitu April 14, 2010 10:45AM

Re: nginx upstream problem

Reinis Rozitis April 14, 2010 01:04PM

Re: nginx upstream problem

Maxim Dounin April 14, 2010 01:24PM

Re: nginx upstream problem

izghitu April 14, 2010 11:49AM



Sorry, only registered users may post in this forum.

Click here to login

Online Users

Guests: 66
Record Number of Users: 6 on February 13, 2018
Record Number of Guests: 421 on December 02, 2018
Powered by nginx      Powered by FreeBSD      PHP Powered      Powered by MariaDB      ipv6 ready