Perceived poor performance

[Daniel L. Miller]

On 1/12/2013 10:28 PM, Steve Holdoway wrote:
> On 13/01/13 19:17, Daniel L. Miller wrote:
>> On 1/12/2013 9:52 PM, Daniel L. Miller wrote:
>>> I don't know if this actually IS poor performance - it just feels 
>>> like it.
>>>
>>> I'm running nginx and php-fpm on a VirtualBox virtual server. No 
>>> other services are running (other than the standard Ubuntu Precise 
>>> minor items for a server).  The VM has four cores and 1G allocated.
>>>
>>> Any time I connect to my server it seems to take 3 seconds before 
>>> the request is processed.  I've seen some references via Google that 
>>> indicate this is TCP related - but I don't know where to look to 
>>> find the break.
>> Further tests show me it isn't for all requests - only requests to my 
>> Wordpress sites, which have a much more complex nginx configuration 
>> that other sites which give me instantaneous response.  What 
>> (improper) commands would have such a major slowdown effect?
> a wp config isn't particularly complex.
>
> What database tuning have you done (are the fast ones also using a 
> database)? yes I know it's remote, but...
> What memory are you allocating to the server?
> How busy is the physical server?
> Are you running a local DNS server?
>
> Sorry I'm not versed in VB, but I run plenty of WP sites off KVM servers.
>
The fast ones are using the same Mysql database.  I've done a little bit 
of Mysql tweaking - I periodically run mysqltuner - but I truly don't 
think that's the issue.

I've got 1G of RAM allocated to the VM.  The physical server has 16G.

The physical server is a 6-core Opteron.  Under "load" - neither the 
host nor the guest show much usage.

I am running a local DNS server (PowerDNS).

While I've already admitted my overall ignorance - I truly don't think 
it's anything else.  I've probably munged my nginx wordpress config - I 
just don't know HOW!  Getting wordpress multi-site running was quite a 
frustration.  I may try to rebuild my config.

One of my issues is I may have tried to be too "elegant" - I like using 
multiple include files to try to avoid duplication.  That way multiple 
configs can share common setups.  I may have broken the config by 
breaking things up too far!  And I don't know if combining fast-cgi 
caching with W3 Total Cache is helping or hurting (assuming of course 
I'm doing it correctly).

For me, the whole "rewrite" process, particularly the combination of 
Wordpress' logic and nginx syntax, has me quite confused.
-- 
Daniel