Database caching?

[lat9]

Thanks, RodG. The site in question is pretty dynamic (products added quite frequently). The client called bluehost yesterday to have them really (unlike the last time they called) turn off the CDN and now the admin and store appear to be working "better"!

[RodG]

Thanks, RodG. The site in question is pretty dynamic (products added quite frequently). The client called bluehost yesterday to have them really (unlike the last time they called) turn off the CDN and now the admin and store appear to be working "better"!

If by 'better' you mean it loads faster, I can only think of one instance where this could be the case, and this is if the store itself is hosted in Australia, and the CDN provider doesn't have a server over here.

CDN's improve performance in two ways.

1) They have multiple servers across the globe - So far less demand is placed on the host server.
2) They use a routing/addressing technology that serves the CDN content from the server in the closest proximity to the client.

Adding *new* products isn't a concern because dynamic pages aren't cached so these will be found from the moment they are activated. The *images* for the product will be automatically cached when viewed by the first customer, leading to better performance for other customers.

The only problems I've had with CDN's is where any *static* content needs to be changed. On a ZenCart site these are generally only going to be the images, and the .css content.

Even the images aren't a problem if the change involves replacing existing images with new ones. The problem only arises if the image(s) are *altered* and the original name is kept. It can take a while (sometimes what seems like eternity) before the CDN's realise that their cached copy is now different from the master copy. This is also compounded because each of the CDN servers have their own cached copy.

IOW, a CDN should never cause performance issues. Theory dictates that they can only improve performance.

Of course, I'm making an assumption here that your 'better' is relating to performance (time it takes a page to load) rather than any other issues that you may have found.

BTW, I'm not basing my comments about performance improvements based on personal observations and/or anecdotal evidence. The effect is quite measurable. Although there are many sites that will test site performance, the one I predominately use is www.webpagetest.org.

Having said that, on a smallish site with few images there aren't many gains to be made. On a site with 1000's of images the difference can be quite dramatic.

Oh, yeah, they can also save on a lot of bandwidth too - I've just 'grabbed' this from one of the CDN's we use for one of our busiests sites:

In the last 7 days 33.09 GB saved
46.23 GB total bandwidth

Not an insignificant saving eh?

Cheers
Rod.