[CentOS] Performance issues/difference of two servers running same task (one is quicker)

[Steven Tardy]

On Thu, Jul 4, 2019 at 2:43 AM Jobst Schmalenbach <jobst at barrett.com.au>
wrote:

> the development and life server in question run the same software setup:
>   - CentOS Linux release 7.6.1810
>   - bind 32:9.9.4-74.el7_6.1
>   - Apache/2.4.6 (CentOS)
>   - PHP 7.1.29
>   - mysqld  Ver 5.7.26
>   - wordpress, woocommerce, wishlistmember, Sensei etc
>   - software are all in the same stages of updates.
>   - even many of the linux conf files are the same (/etc/host, bind, etc)
>   - the databases are copies/identical
>
> Life server is a Poweredge M710,48GB,2xXeon L5630,LSI Raid1 SSD
> Dev  server is a DIY, GIGABYTE MX31-BS0, 32GB, 1xXeon E3-1245,MDADM RAID0
> 1TB Seagate Spinners
>
> During normal operations (i.e. display websites, online training courses
> etc) the DELL
> displays the websites faster although it sits 1000KM up north in a
> datacenter on
> a different network than the local server on the same network as my
> machine.
>
> Yet the DEV server outshines the DELL when creating a few large custom
> tables, ie
> the local server takes 5s while the DELL takes 15s (small tables), more
> for bigger tables.
>
>
> I have put microtime() calls before and after certain calls, and it's
> visibly different:
>   DEV
>     Jul 04 04:57:26 UTC _members took 0.0005459785461425 ms
>     Jul 04 04:57:26 UTC _members took 0.0005321502685546 ms
>   LIFE
>     Jul 04 05:00:36 UTC _members took 0.0014369487762451 ms
>     Jul 04 05:00:36 UTC _members took 0.0013291835784912 ms
> If I do this 300+ times, the outcome is very different.
>
>
> So my questions:
>
>  - How can it be that the DELL takes so much longer alltough on the far
> better hardware?
>  - How can it be allthough everything (software/os/plugins) is the same?
>  - This even happens if the DELL is on low load (i.e. middle of the night)
> and
>    only serves a few requests.


As others have said the DEV server is a generation newer CPU. For CPU
details I often reference Intels “ark” pages:

https://ark.intel.com/content/www/us/en/ark/products/47927/intel-xeon-processor-l5630-12m-cache-2-13-ghz-5-86-gt-s-intel-qpi.html
  12M Cache, 2.13 GHz, 5.86 GT/s Intel® QPI


https://ark.intel.com/content/www/us/en/ark/products/52274/intel-xeon-processor-e3-1245-8m-cache-3-30-ghz.html
  8M Cache, 3.30 GHz

The “generations” I mentioned are:
   Code NameProducts formerly Westmere EP
<https://ark.intel.com/content/www/us/en/ark/products/codename/54534/westmere-ep.html>
   Code NameProducts formerly Sandy Bridge
<https://ark.intel.com/content/www/us/en/ark/products/codename/29900/sandy-bridge.html>

Westmere systems used DDR at 800/1066MHz.
Sandy Bridge systems used DDR at 1066/1333MHz.
Not a huge difference, but likely another contributing factor of
performance.

I would also look at power settings in the BIOS and c-state settings in the
BIOS and OS as disabling c-states (often enabled by default to meet
green/energy star compliance) can make a noticeable performance difference.


Hope that helps.