Cache size increase

It seems settin wp_cache_gc to run every hour made the cache size less than 2.2GB, which is a good news but it’s still too big.

Whats weird is that all of the posts on this ↓ category is caching the most:

https://jazztokyo.org/category/reviews/kimio-oikawa-reviews/

This category hasn’t been updated since March 2022 due to a writer’s health issue. Despite the amount of caching, I don’t think there are that many visitors to this category.

• This reply was modified 3 months, 4 weeks ago by madflute.
• This reply was modified 3 months, 4 weeks ago by madflute.
• This reply was modified 3 months, 4 weeks ago by madflute.

Unfortunately, without access to your server, I can’t say for sure why that’s happening. It may be a misbehaving plugin that’s making extra queries to your site, I don’t know, sorry.

WP Super Cache is definitely making an impact on how well your site runs. The first time I looked at that page, there was a noticeable lag while it loaded, but when it was cached, it loaded very fast.

Hi @donncha

Is there any way to exclude this subcategory from caching? If that is possible, my headache would go away ??

Yes, there is. Look at the Advanced settings page for the “Rejected URL Strings” section where you can enter some strings from the posts in that category, I think if you add “/reviews/” without the quotes there, it should stop those posts caching.

That might cause the webserver to run more slowly though, as there is someone online hitting those pages for some reason.

Thank you @donncha

The exact subcategory URL is

https://jazztokyo.org/category/reviews/kimio-oikawa-reviews/

So, the string should be this? ↓

/reviews/kimio-oikawa-reviews/

Hi @madflute,

Hi there,

Yes, adding /reviews/kimio-oikawa-reviews/ to the “Rejected URL Strings” section in the Advanced settings should prevent caching for that specific subcategory. This should help manage your cache size better.

Keep in mind that excluding pages from caching might increase server load if those pages are accessed frequently.

Give it a try and let us know how it goes.

Hey @madflute,

Do you have updates about that, do you still need help? We usually close inactive threads after one week of no movement, but we want to make sure we’re all set before marking it as solved. Thanks!

Hi @erania-pinnera

Thank you for checking. We are OK now. I am not sure why the garbage collector and its notification stopped working, but forcing wp_cache_gc to run seems to be working. Also, why the very dated section no one accesses is caching huge is still a mystery, but excluding that section did help. This whole thing is very mysterious, especially since it has worked for many years.

Hi @madflute –

Thanks for confirming that it is working; that is great news!

I’m going to mark this thread as resolved now. If you have additional issues or questions in the future, feel free to open a new thread.

Hi @lastsplash

As soon as I thought everything is working OK, the cache size jumped up to 6GB and choked the server. I really don’t understand what is going on ??

I think your site is getting hit by a lot of bots, and they might not be checking if the page is really different. The “last modified” time on a blog post isn’t the published time because widgets in the sidebar or content elsewhere on the page might have updated.

Also, 6GB isn’t a whole lot when you look at the size of the page. The most recent review on the site is 217Kb. 28 such reviews will take up 6,144Kb if they’re all cached. There’s more than 28 reviews. If you can make the page smaller, that will help.

On the Advanced settings page, did you enable compression? That will make the pages smaller, but if it’s bots hitting your site that don’t support compression, then the pages won’t be stored compressed.

Thank you for your response @donncha

I just turned the compression on, and 304 browser caching while I was there. Hope this will make some differences. Will report back. Thank you again!

Hi @madflute,

Thank you for the update! Let us know how it goes after enabling compression and 304 caching.

Cheers!

Hi @alinclamba

Does the compression option actually add .gz file next to the actual file? I was surprised the disk usage went up, only to realize there are .gz files I previously did not see. Is this the expected behavior? The host server space is 80+% full and we don’t have options to get more space. This is why I have been trying to reduce the cache size as much as possible.

Hi @madflute,

The .gz files are compressed cache files so your cache files are taking up less space.

What you need to do is identify what is visiting your webserver so aggressively.

It’s probably bots, and if it is, you can either ban those user agents or their IP addresses from your server, but that’s beyond the scope of support here, sorry. Or you can stop WP Super Cache from creating cache files for them. They’ll get slower pages but that won’t really matter, except that the load on the server will go up. Look up the “Rejected User Agents” section in the Advanced settings page. Put the useragent you find in your logs there, and the plugin won’t create cache files for them. The useragent is the name of their browser, or the bot name.

It might be worth downloading the contents of the cache directory and checking that each file is the expected size. If you find a file that’s huge, beyond the size of the page it caches, or is being requested directly, maybe there’s a vulnerability on your server and someone is using your server as storage. This is unlikely.

1. Download your webserver access logs.
2. Examine them for what is hitting your site.
3. Look for patterns of aggressive visitors and ban them.
4. Check the files in your cache directory to make sure they’re the proper size. Just in case.

There’s not much else we can do, unfortunately. Sorry.