very slow frontend, backend, 503 error often

[delta37]

This started lately when the site (www.glamourbox.ph) started to attract more customers.

 

The site runs on a dedicated server with a couple more domains but with very low traffic. Only Glamourbox has high foot traffic for the past couple of weeks.

 

Server specs is dual core with 8GB RAM and is run by Pixelgate Networks

 

My TTFB usually hovers at around 30sec and up sometimes even 90sec.

 

I tried several options already.

 

1. Delete the connections, connection_page, connection_source database

2. set memory_limit at 512M, max_execution_time 6000, max_input_time 600

3. disable a lot of the statistics module (e.g. best customer, best product, page error, etc...)

4. disable file system cache

5. Already upgraded server from 4GB to 8GB 

 

Some things to note:

 

1. It's a beauty products site and so client wants a lot of high res photos (they insist)

2. We modified the theme heavily to accommodate the design they want.

3. We have a number of plugins installed and modded either for aesthetic purposes or for local market

 

 

Any more suggestions where to look? I usually get the 503 error (capacity problem or maintenance) often but I have already upgraded the RAM to 8GB. They are time that my usage of RAM goes up to 80%. I figured it's not about the RAM anymore since nothing changed when I upgraded my RAM.

 

Thanks in advance

 

[Dh42]

It looks like you have some issues with modules either being modified poorly, or cache issues, these modules are you problem http://screencast.com/t/KShoUuvFq  It takes over 30 seconds for the product comments module to load. 

[delta37]

Thanks for this. Just a quick update, we currently disabled cache and maybe that's why the productcomments module spiked? But I have also temporarily disable that module right now after seeing your report. We will install the APC caching extension later this day and see if it improves speed. I will have my team re-check the said module also

 

Thanks again bud

[delta37]

Just an update:

 

We have managed to install the APC extension finally. After enabling it on Prestashop, it did indeed load much faster (the contents loads in 2-3 sec) BUT I'm having 2 issues;

 

1.) My TTFB is still something like 12sec on average.

 

2.) I get an Error 500 every now and then.

 

Any suggestions or tools I can use to diagnose where the error is coming from? and how to make my TTFB faster?

 

Thanks!

[Dh42]

A slow server is more than likely your problem. Also if you are running APC and not APCu then it means you are using an older slower version of PHP. I would upgrade to 5.6 and use opcache instead. If you are on a latest version of PrestaShop you can try php7 and opcache

[delta37]

I googled APCu and correct me if I'm wrong but is APCu only compatible with PHP 5.5? 

 

We are currently running PHP 5.6 on Prestashop 1.6.1.1

 

If I use opcache, which cache should I use in Prestashop performance settings?

[Dh42]

APCu supports version 5.3 - 7, https://pecl.php.net/package/APCu  

 

I wouldn't use APCu though, you will see no noticeable speed increase. You will more than likely just see erratic behavior when your are logged in. It only caches user information.Opcache just works, it doesn't need a setting in prestashop.