Database caching?

[lat9]

I've got a client running a highly-customized Zen Cart v1.5.1 that recently transferred to bluehost (yes, I know ...) on PHP 5.4.43 and just ran into the weirdest thing:

I go to one of the configuration screens and change the first value in the list. Upon clicking the "Update" button, I'm returned to the overall configuration display ... but the value hasn't been changed. I can click the next item in the configuration screen and, like magic, the change I made to the first item now displays! This is using the built-in configuration handling in the Zen Cart admin.

I've checked the configure.php files to ensure that all the file-paths are proper (they are) and the Configuration->Sessions to make sure that the session-save-directory is the /cache folder (it is).

There are other bits of funkiness going on on this site after the move, but I believe that the above issue is a large, underlying factor.

I'd appreciate any/all clues or other pieces of information to hunt up.

[kobra]

As you know

Zen Cart v1.5.1 is compatible with PHP 5.2.14 thru PHP 5.3.x.

This is a place to start

[lat9]

Yes, the site's been kept up with the various changes so that's not it.

Edit: There was no issue when the site was on its previous host, also running a later version of PHP 5.4.

[lat9]

Arggh. Discussing the issue with the client, bluehost apparently offered them a "performance improvement" if they configured the site to act as a CDN. Working now to remove remnants of that change; it certainly would explain all the funnies I was seeing on the site.

[RodG]

Arggh. Discussing the issue with the client, bluehost apparently offered them a "performance improvement" if they configured the site to act as a CDN. Working now to remove remnants of that change; it certainly would explain all the funnies I was seeing on the site.

CDN's a generally a good thing - and yes, they can/do offer some *huge* performance benefits. I recommend using a CDN whenever possible.

Yup, there can be downsides to them - Especially during any development work (and various other changes) due to the delay caching affect, but of the few CDN services we use, they've all had a 'development' mode that temporarily bypasses the caching, and they'll all had an option to clear the cache contents - individual files, folders, or the entire site.

Just my 2cents worth,

Cheers
RodG

[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"!

[kobra]

they configured the site to act as a CDN

Glad you discovered this - dynamic sites do not play well with cloud services

[RodG]

Glad you discovered this - dynamic sites do not play well with cloud services

Kobra! You should be ashamed of yourself for making such a simplistic comment such as this.

You/We could also say the *exact* same thing about the caching provided by all web browsers as well as all proxy servers that are implemented (often transparently) by almost every ISP on the planet.

A CDN is just another cache, and like all caches, they only cache static content.

This very busy ZenCart site appears to be playing very nicely with the CDN. As can be clearly seen, the bulk of the content on this dynamic site are the static images. The bandwidth saved and performance gained (by not having to server the requests from the master/host server are clearly quite significant.

In what way can this be considered as 'not playing well'?

Cheers
RodG