trafficserver-users mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Philip <flip...@gmail.com>
Subject Re: ATS performs poorly proxying larger files
Date Thu, 21 Mar 2013 11:42:33 GMT
I've just upgraded to ATS 3.3.1-dev. The problem still is the same:
http://i.imgur.com/1pHWQy7.png

The load goes on one core. (The server is only running ATS)

2013/3/21 Philip <flips01@gmail.com>

> Hi Igor,
>
> I am using ATS 3.2.4, Debian 6 (Squeeze) and a 3.2.13 Kernel.
>
> I was using the "traffic_line -r" command to see the number of origin
> connections growing and htop/atop to see that only one core is 100%
> utilized. I've already tested the following changes to the configuration:
>
> proxy.config.accept_threads -> 0
>
> proxy.config.exec_thread.autoconfig -> 0
> proxy.config.exec_thread.limit -> 120
>
> They had no effect there is still the one core that becomes 100% utilized
> and turns out to be a bottleneck.
>
> Best Regards
> Philip
>
>
> 2013/3/21 Igor Galić <i.galic@brainsware.org>
>
>> Hi Philip,
>>
>> Let's start with some simple data mining:
>>
>> which version of ATS are you running?
>> What OS/Distro/version are you running it on?
>>
>> Are you looking at stats_over_http's output to determine what's going on
>> in ATS?
>>
>> -- i
>>
>> ------------------------------
>>
>> I have noticed the following strange behavior: Once the number of origin
>> connections start to increase and the proxying speed collapses the first
>> core is at 100% utilization while the others are not even close to that. It
>> seems like the origin requests are handled by the first core only. Is this
>> expected behavior that can be changed by editing the configuration or is
>> this a bug?
>>
>>
>>
>> 2013/3/20 Philip <flips01@gmail.com>
>>
>>> Hi,
>>>
>>> I am running ATS on a pretty large server with two physical 6 core XEON
>>> CPUs and 22 raw device disks. I want to use that server as a frontend for
>>> several fileservers. It is currently configured to be infront of two
>>> file-servers. The load on the ATS server is pretty low. About 1-4% disk
>>> utilization and 500Mbps of outgoing traffic.
>>>
>>> Once I direct the traffic of the third file server towards ATS something
>>> strange happens:
>>>
>>> - The number of origin connection increases continually.
>>> - Requests that hit ATS and are not cached are served really slow to the
>>> client (about 35 kB/s) while requests that are served from the cache are
>>> blazingly fast.
>>>
>>> The ATS server has a dedicated 10Gbps port that is not maxed out, no CPU
>>> core is maxxed, there is no swapping, there are no error logs and also the
>>> origin servers are not heavy utilized. It feels like there are not enough
>>> workers to process the origin requests.
>>>
>>> Is there anything I can do to check if my theory is right and a way to
>>> increase the number of origin workers?
>>>
>>> Best Regards
>>> Philip
>>>
>>
>>
>>
>>
>> --
>> Igor Galić
>>
>> Tel: +43 (0) 664 886 22 883
>> Mail: i.galic@brainsware.org
>> URL: http://brainsware.org/
>> GPG: 6880 4155 74BD FD7C B515  2EA5 4B1D 9E08 A097 C9AE
>>
>>
>

Mime
View raw message