# Upstream server max\_fails and fail\_timeout question/discussion

**URL:** <https://www.ruby-forum.com/t/upstream-server-max-fails-and-fail-timeout-question-discussion/195865>\
**Category:** NGINX\
**Created:** [October 1, 2010, 3:33pm UTC](https://www.ruby-forum.com/t/upstream-server-max-fails-and-fail-timeout-question-discussion/195865 "2010-10-01T15:33:12Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![rsawer](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/dc4da7/32.png) [@rsawer](https://www.ruby-forum.com/u/rsawer)\
**Post date:** [October 1, 2010, 3:33pm UTC](https://www.ruby-forum.com/t/upstream-server-max-fails-and-fail-timeout-question-discussion/195865/1 "2010-10-01T15:33:12Z")

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Hi!  
I have a question about the impact of the max\_fails and fail\_timeout  
settings to the error pages which nginx is showing.

First, the God created an upstream:  
upstream my\_upstream {  
server 192.168.104.58:81 max\_fails=2 fail\_timeout=30m;  
server 192.168.104.58:82 max\_fails=2 fail\_timeout=30m;  
}

I’m just checking the nginx behaviour to know what error pages will it  
display in case of different errors, so on the upstream server I have  
firewalled connections to the port 81 and 82 by iptables -I INPUT -p tcp  
–dport 81 -j DROP (and the same for port 82)

Testing:  
a) First request - after timeout for backends Nginx’s giving 504 error  
page (gateway timeout) which is correct (and it’s 1st FAIL for  
max\_fails)  
b) Second request - as above, after timeout Nginx’s giving 504 error  
page (2nd FAIL so the max\_fails limit is reached) which is also correct  
c) Third request - All backends are in fail state, so Nginx immediately  
gives 502 error page (bad gateway)

And here my doubts begin. With 4th,5th,6th, etc requests I thought I  
will be getting 502’s unless the 30 minutes fail\_timeout will end. And  
instead of that what I see is that Nginx’s is resetting the max\_fails  
value if all servers in upstream clause have reached the max\_fails.

What I wanted to ask is if this a proper behaviour?  
I think that there should be an another configuration parameter which  
would tell nginx what to do in such cases.

For me it’s quite logical that nginx’s resets this value, so it can try  
to check if the backend/upstream server is alive, instead of giving  
502’s for 30 minutes fail\_timeout, but the world is big, and I think  
there are people that would like Nginx to throw 502’s for fail\_timeout  
period. What do you think about that ?

Best regards,  
Rafal Sawer - satisfied Nginx user 🙂

Posted at Nginx Forum:

> **[upstream server max\_fails and fail\_timeout question/discussion](https://forum.nginx.org/read.php?2,135988,135988#msg-135988)**
>
> Hi! I have a question about the impact of the max\_fails and fail\_timeout settings to the error pages which nginx is showing. First, the God created an upstream: upstream my\_upstream { server 192.168.104.58:81 max\_fails=2 fail\_timeout=30m; server...

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**Author:** ![rsawer](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/dc4da7/32.png) [@rsawer](https://www.ruby-forum.com/u/rsawer)\
**Post date:** [October 3, 2010, 1:32pm UTC](https://www.ruby-forum.com/t/upstream-server-max-fails-and-fail-timeout-question-discussion/195865/2 "2010-10-03T13:32:03Z")

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Hello!

On Fri, Oct 01, 2010 at 09:32:00AM -0400, rsawer wrote:

[…]

> And here my doubts begin. With 4th,5th,6th, etc requests I thought I  
> will be getting 502’s unless the 30 minutes fail\_timeout will end. And  
> instead of that what I see is that Nginx’s is resetting the max\_fails  
> value if all servers in upstream clause have reached the max\_fails.

Yes.

> What I wanted to ask is if this a proper behaviour?  
> I think that there should be an another configuration parameter which  
> would tell nginx what to do in such cases.
> 
> For me it’s quite logical that nginx’s resets this value, so it can try  
> to check if the backend/upstream server is alive, instead of giving  
> 502’s for 30 minutes fail\_timeout, but the world is big, and I think  
> there are people that would like Nginx to throw 502’s for fail\_timeout  
> period. What do you think about that ?

There is a little sense in returning 502, and that’s why “down due  
to max\_fails” status is reset once nginx detects there are no live  
upstreams.

Maxim D.