No cache created by WordPress 2.0.2

You have to enable the cache in wp-config.php for it to be created.

It is currently disabled by default as it was causing to many problems to support on every hosting configuration.

Add the following to wp-config.php


define('ENABLE_CACHE', true);


And then it should be enabled.
You can check its working with my cache inspector plugin – https://blog.ftwr.co.uk/wordpress/wp-cache-inspect/

I wouldn’t enable the cache with WordPress 2.0.2 … you open yourself up to one of the security vulnerabilities that 2.0.3 addresses.

Very true Mark! I forgot to recommend that above.

The instructions will of course work for 2.0.3 just as well.

Ok, I’ve enabled the cache in wp-config.php

No change – cache directory stays empty.

I installed your plugin westi, but I don’t see:

a small semi-transparent box in the top right hand corner of the page

I do now have a page at Manage > Cache, but the only content is a button to ‘Clear the Cache’.

I understand about the security issue, but need to troubleshoot first.

Correction to my comment above – I do now see the semi-transparent box on each page.

Cold Cache Hits stays at: 2
Warm Cache Hits increases by about 4-5 each page load.
Cache Misses: mostly stays at 15, occasionally drops to 13-14.
Loaded data: 12 pages (what I would expect).

However, /wp-content/cache/ remains empty.

If the cache folder is staying empty then WordPress can’t write to it.

There will still be some cache hits as the cache will be used ,within a single page load, instead of requesting the same info multiple times from the database

Westi says:

then WordPress can’t write to it

Any clue about what might be stopping it?

I’ve done a second WP installation on the same server, and this also will not write to cache, even with the instruction in wp-config.php.

Also, I’m puzzled your first reply:

It is currently disabled by default

I have WP 2.0.2 running on several other hosts, and the cache started working straight out of the box – no modification needed to wp-config.php.

I am beginning to think I might have an unsuitable host (I’m already on their case about intermittent timeouts when loading pages), but I would like to be certain that I have eliminated any possibility of mistakes at my end.

Hi,

the cache is not as efficient as expected. Use WP-Cache with this fix if you want to speed up your blog.

should be sticky… many people don’t read this..

they think everything works without adding the code..

I know about WP-Cache. Unfortunately it seems to require SSH or Telnet access to the webserver (although the author is strangely reluctant to answer questions about this).

I trying to find out if there is something wrong with the shared hosting server I am using that causes the ordinary WP cache to fail.

If it is a server configuration that can be corrected I will ask the webmaster to do so.

If it can’t be corrected, I need to know what I should be checking for when evaluating a replacement host.

Unfortunately it seems to require SSH or Telnet access to the webserver

Strange. Shouldn’t. What specifically are you trying to do while SSHing in?

drmike says:

What specifically are you trying to do while SSHing in?

Like most WP users, I only have FTP access to my server. Ricardo’s instructions start:

Step 1. Upload to your plugins folder, usually wp-content/plugins/ and unzip the file

I can’t find any information on how to do this. Every other plugin I unzip on my hard drive then upload, but this does not produce the necessary result:

it will create a wp-content/plugins/wp-cache/ directory.

Then the instructions say:

Step 5. Create a symbolic link from wp-content/advanced-cache.php to wp-content/plugins/wp-cache/wp-cache-phase1.php.

Reading down past lots of unanswered questions about this I finally see comment 351:

Clueless, what you need to do is login using SSH (or Telnet) to your server with a user that has the rights to make symbolic links.

If you are able to explain how an ordinary WP user on a shared host can achieve this it would probably be more appropriate on the plugin page I’ve linked to.

I appreciate your help, and the information on how to install the WP-Cache plugin will be very useful to lots of people who can’t get an understandable answer from the author.

However, I’d still like to know why the webserver I am on is not behaving and if it can be fixed.

Hi,

just try to upload it like every other plugin.

• Unzip it on your hard drive, upload the whole unzipped wp-cache folder into wp-content/plugins/)
• Then go to the administration panel and activate it.
• After that, you’ll see a submenu called WP-Cache in the Options menu.
• If you click on this the first time, the plugin will try to create the symbolic link for you, so you don’t need SSH or Telnet.
• If something fails due the lack of writing permissions, the plugin will tell you what you have to do.

If you need to change file or folder permissions, have a look at Changing File Permissions at the WordPress Codex.

Best regards,

Arne

Thanks for the simple explanation, Arne.

The installation went fine – no error messages – no apparent problems.

WP-Cache is now Enabled with default configuration.

Cache contents reported as:
0 cached pages
0 expired pages

And no extra code appears in pages to indicate cache is working.

If I try to look in wp-content/cache with my FTP programme to see if anything is there, I get:
550 permission denied

I cannot change permissions on
wp-content/cache (currently: rwx — —)
or wp-content/advanced-cache.php (currently: rw- r– r–)
because user is ‘apache’, not me.

typically the ftp user is owner of files on ‘good’ systems. even on ‘bad’ systems, the ftp user should have full owner-level control over anything created in your tree by the apache user (if not, must be a permissions issue — mask, group, something… talk to your sysadmins).

don’t bother using the ‘object cache’ of WP2 on any standard shared server — it basically makes no impact. The only time it’d make some impact is when you have a very heavily hit SQL server and lightly hit webserver…

wp-cache is the plugin of choice. sounds like it got installed properly, but you may need to delete the /cache directory (or, again, talk to sysadmins — sounds like something odd on your box there!).

-d