could you please explain what these numbers mean: A4838400 at this entry: ExpiresByType

[ibiza]

Hi, could you please explain what these numbers mean: A4838400 at this entry: ExpiresByType text/x-javascript A4838400 at <IfModule mod_expires.c>

We need to update the expiring time, and with these numbers, we don’t understand how to proceed, or if they can be changed to for example: 1 week, 1 month, 1 year (and which would be the options), instead of the numbering we don’t understand.

Thank you very much!!

[AITpro Admin]

Apache Module mod_expires > ExpiresByType Directive > https://httpd.apache.org/docs/current/mod/mod_expires.html

ExpiresByType MIME-type code seconds

A is the code and 4838400 are the seconds. 4838400 seconds divided by 60 = 80,640 minutes. 80,640 minutes divided by 60 = 1,344 hours. 1,344 hours divided by 24 = 56 days.

M means that the file’s last modification time should be used as the base time, and A means the client’s access time should be used.

1 day in seconds = 86400

1 week in seconds = 604800

1 month in seconds = 2592000

1 year in seconds = 31104000

[ibiza]

Thank you!! Just one thing, what do you mean with this, I mean, we have an A at the front of the number, but we don´t have an M, so what difference makes changing the letter, we didn´t undertand this:

M means that the file’s last modification time should be used as the base time, and A means the client’s access time should be used.

We saw at the link you shared that its possible to change that for these:

ExpiresDefault "access plus 1 month"
ExpiresDefault "access plus 4 weeks"
ExpiresDefault "access plus 30 days"

But don´t really understand how we should chenge this for that:

ExpiresByType text/x-javascript A4838400

The problem I’m facing it’s that we have a plugin called: PWA — easy way to Progressive Web App, that is generating us tons and tons of cache transients, up to 75.000 daily and the developer says that: “will disappear when the cache lifetime expires.”, but we don´t know how to clear this cache after a few hours, for example after 3 hours daily. Any idea? We can´t use cache plugins like WP Rock as break our websites, we have tryed and tryed and our plugins won´t accept them.

Hopefully you can share some knowledge.

Sorry, for my english, I’m from Spain, hopefully you understand we my concerns.

Thank you for your time and dedication once more.

[AITpro Admin]

Yes, you can use this syntax below for the ExpiresByType Directive. Note: below are 3 examples for the text/x-javascript MIME-type. You would of course have many different MIME types in your htaccess code and would only be changing the expiry time from seconds to readable text.

ExpiresByType text/x-javascript "access plus 1 month"
ExpiresByType text/x-javascript "access plus 4 weeks"
ExpiresByType text/x-javascript "access plus 30 days"

Transients means database cache and not browser cache. The htaccess cache code is for browser caching. Transient DB cache is stored in the WordPress Database. The plugin should have a tool/option to delete transient DB cache. All caching plugins come with tools/options to delete/purge cache.

[ibiza]

Thank you once more for all your explanation. Have a very nice time!

[AITpro Admin]

I just looked at the plugin on wordpress.org and it only creates cache for mobile devices. It does not appear to have a delete/purge cache option. Looks like it is a very new plugin. So at some point after enough people complain about the problem you are having the plugin author will add that option, which of course should have been a top priority that should have already been added in that plugin. You can manually delete transient DB cache in phpMyAdmin in your web host control panel, but that would be a pain to do on a regular basis. There is probably a WordPress plugin that you can install that will do that with 1 click.

[AITpro Admin]

Oh I checked Advanced View on the wordpress.org plugins page and that plugin has been around for a long time. It’s just not installed by many people.

[ibiza]

Yes, the plugin seem to have been around for long. I read in another post on their support forum that the same thing was happening to another user.

I’m going to write to the plugin’s creator to ask them to please include this option (clear cache), and see what they say.

Thank you so much again for your tremendous help and advice.

[Author]

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