Re: Rails app with maxconn 1 receiving more than 1 request at a time

For the record, I have seen this as well lately. I was planning to report it when I had time to dig up more data, but Rupert beat me to it. Here's an example of what I see on one of my instances: http://skitch.com/signalmark/i5j1/haproxy-maxconn-bug

I'm wondering if this is a regression in 1.13.3.3 since I don't see similar numbers in the HAproxy stats on 1.13.3.2.

-Mark

On Sep 12, 2008, at 9:04 PM, Brian Gupta wrote:

> I am confused why you are seeing more "max" sessions than "limit"
> sessions. This shouldn't be happening.
>
> -Brian
>
> On Fri, Sep 12, 2008 at 8:44 PM, Rupert Fiasco <rufiasco#gmail.com>
> wrote:
>> The max conns on the stats seems to be crazy high.
>>
>> http://brockwine.com/images/haproxy_stats.png
>>
>> Also, what constitutes an error/warning? I seem to be seeing a lot of
>> those as well. Does that mean by backend is returning a bunch of HTTP
>> 500 or is it an internal haproxy error/warning?
>>
>> Thanks
>> -Rupert
>>
>> On Fri, Sep 12, 2008 at 5:15 PM, Brian Gupta
>> <brian.gupta#gmail.com> wrote:
>>> Curious, what is the haproxy stats page reporting for maxconns for
>>> the
>>> individual backends? IE: Is haproxy also seeing peaks of high
>>> connection counts?
>>>
>>> -Brian
>>>
>>> On Fri, Sep 12, 2008 at 8:03 PM, Rupert Fiasco
>>> <rufiasco#gmail.com> wrote:
>>>> We are running 1.3.15.3 and have haproxy in front of a cluster of
>>>> mongrels. We have a plugin in the mongrels that displays the
>>>> mongrels
>>>> current queue length.
>>>>
>>>> With a haproxy config line like:
>>>>
>>>> server server-0 127.0.0.1:9000 maxconn 1 check inter 30s
>>>> slowstart 10s
>>>>
>>>> This should mean that haproxy will *NEVER* send more than 1
>>>> request to
>>>> that backend. Yet our plugin is reporting that it has sometimes 10+
>>>> requests queued up.
>>>>
>>>> Is my config wrong?
>>>>
>>>> Thanks
>>>> - Rupert
>>>>
>>>>
>>>
>>>
>>>
>>> --
>>> - Brian Gupta
>>>
>>> http://opensolaris.org/os/project/nycosug/
>>>
>>> http://www.genunix.org/wiki/index.php/OpenSolaris_New_User_FAQ
>>>
>>
>
>
>
> --
> - Brian Gupta
>
> http://opensolaris.org/os/project/nycosug/
>
> http://www.genunix.org/wiki/index.php/OpenSolaris_New_User_FAQ
>
Received on 2008/09/13 03:23