CACHE settings

[djslue]

Right now it is disabled. I did a little reading on it. It seems I should have it enabled and this setting either Conservitive or Progressive.

and should I have system cache enabled and this browser cache on ?

[NickC4555]

You should normally have the cache in global configuration on, set to conservative. The system cache plugin enables browser page caching and can improve performance, but it sometimes causes problems with sites that require authentication and with third party components. If your server supports it, also switch on gzip compression.

[djslue]

"problems with sites that require authentication" My site is setup with SSL. Would that casue any issues ?

[NickC4555]

No, it's the Joomla login process that sometimes causes an "invalid token" error when browser page caching is enabled. You can exclude your login page in the plugin settings, though.

[djslue]

Ok thanks. I'll check that out

[djslue]

So would you suggest just the Conservative cache on and leave off the browser cache ?

[NickC4555]

They are entirely separate, one is server side, the other is client. They both, depending on your infrastructure and components, can realise performance improvements, but should be tested independently.

[djslue]

What is the best way to test ? What errors shold I be looking for ?

Thanks for the help !

[sozzled]

Forgive my late intrusion into this topic. From what little I've read—perhaps I've misunderstood the discussion—I don't know if people understand what they're talking about.

Yes, there are two sides to caching: there's caching that occurs on the server (where your website lives, where the PHP software responds to HTTP GET requests and "serves" packages of information—basically HTML code) there's caching that occurs at the browser (where "you" live). There is no engagement between server side caching and browser caching. They are completely different things.

Caching is useful (to improve the end-user's personal experience) and it can be a pain in the neck at other times. If your website is dynamic (in the sense that the site content is being continually updated, e.g. if you are running a busy discussion forum) server-side caching can be a complete waste of time. In sites where the content is dynamic, more time can be spent loading/clearing the cache instead of actually serving the content. On the other hand, if the content is "relatively" static, caching can be a blessing because visitors to your site will not have to wait as long for the information they've requested to be packaged and delivered to them.

What are the best, "optimum" settings to use for caching? The settings depend, to some extent, on the amount of traffic your site handles, the volume and frequency of changes you're making to the site, and gauging the user's experience (perhaps, through the use of site analytic software). As a rough rule-of-thumb, when I'm building a website and I know I'm going to be making wholesale changes in the first couple of weeks, I disable all caching on the server. As a rough rule-of-thumb, I enable progressive caching for relatively static sites and conservative caching for relatively dynamic sites and "no caching" for sites whose content is changing every few minutes.

Ultimately, however, the performance of a website can be improved through caching; the end-user's experience can be improved or degraded as a result of caching (particularly if stale pages are served because the cache needs to be flushed). Overall performance depends on the hosting platform. Caching at the server is just one aspect of site performance.

[NickC4555]

What is the best way to test ? What errors shold I be looking for ?

Thanks for the help !

1. That your website functions as intended, testing all of its required functionality.
2. That each of the caching methods independently produce performance gains or not.

[sozzled]

They are entirely separate, one is server side, the other is client.

Basically, that's what I also wrote.

They both, depending on your infrastructure and components, can realise performance improvements ...

To a certain extent, yes, but let's keep things in perspective. Joomla relies on the features embodied in the server; what occurs on the client is entirely different and Joomla has next to no control over those things. While most of us use our web browsers with caching enabled (and some people choose to disable those features) the website is "browser agnostic".

As an illustration of what is cached and what is not cached, my "favourite" example is the file favicon.ico. This is a file that's cached by the browser. A simple way to prove this is to load a website into the browser (with browser caching enabled), then replace the standard favicon.ico file supplied by Joomla with another one, and then re-load the page. It doesn't matter how many times you try to clear the server cache, the browser will still display the originally-loaded favicon.ico file until you "blow away" the browser cache. Right?

Yes, you can "test"/experiment with each side's—server and browser—caching settings but remember that, in live operation, there's virtually nothing in Joomla that controls caching at the browser end. Caching at the browser end is totally in the hands of the end user.