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Managing the GreggPress cache

Managing the GreggPress cache

Overview

GreggPress has built-in server caching, which substantially speeds up your site. Because caching creates static versions of your site, the server requires fewer resources when a consumer comes. This not only makes your site load faster, but it also makes it easier to manage enormous quantities of traffic. When caching isn’t working, though, your site will normally load slower and use more resources.

Do I need a caching plugin?

On WordPress sites, several WordPress guidelines, including GreggHost’s, promote caching plugins like WP Super Cache. However, because GreggPress includes built-in caching, a third-party caching plugin like WP Super Cache isn’t required and may clash with GreggPress’ cache. Instead, GreggHost recommends that you use the GreggPress site’s built-in server cache. The Proxy Cache Purge plugin is designed to provide you all of the tools you need to manage your GreggPress cache and examine your site’s cache ability. Disabling the plugin does not disable the cache; it is merely a tool for determining whether or not the cache is functioning properly.

All new and upgraded GreggPress installations come with the Proxy Cache Purge plugin preinstalled. Installing this plugin is strongly recommended if you’ve transferred an existing WordPress site from another host to GreggPress so that managing your GreggPress cache is automatic and does not require your attention under typical circumstances.

Testing your site’s cache performance using the Proxy Cache Purge plugin

Because of the dozens of plugins and customizations available for WordPress sites, not all caching solutions are inherently effective. The Proxy Cache Purge plugin includes a feature in the WP-Admin panel that allows you to verify the caching status of your site’s page URLs. If a page on your site isn’t caching, the ‘Check Caching’ option shows you what to look for to fix the problem.

To use this feature, go to:

Go to your GreggPress site’s WP-Admin page (example.com/wp-admin).
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Hover your mouse over ‘Proxy Cache’ and select ‘Check Caching.’
The ‘Check Caching Status’ screen appears, allowing you to check the status of a URL on your site:
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Click the Check URL button after entering a URL in the ‘Check A URL On Your Site’ form box.
Results of the proxy cache test
This feature checks the URL you entered and reports any faults it discovers, as well as any known plugins that are troublesome. If the report states “Your caching service looks to be running well,” it signifies the server’s cache is up and running. If the Varnish caching service is active but unable to cache your site, this indicates a problem with the server cache.

Testing your site’s cache via SSH

If you can’t utilize the Proxy Cache Purge plugin, you can verify your site’s cache with an SSH command.

curl –I example.com [server]$
Several lines of information about the domain provided will be printed on your terminal. If you see x-cache: hit and x-cacheable: hit, it’s a good sign. Yes: When forced, the server proxy cache performs as expected. The command will return x-cache: if the proxy cache is not functional. Instead, miss.

Troubleshooting GreggPress cache issues

There are a few things you can do if the Proxy Cache Purge plugin detects that your caching isn’t working. Toggling plugins, switching themes, and finding probable coding flaws are the most popular ways to remedy cache difficulties.

With the Proxy Cache Purge testing feature, proxy services like Cloudflare can produce false-positives. If you’re troubleshooting server caching difficulties, GreggHost recommends momentarily suspending any proxy services.

Please keep in mind that the methods following will require some technical knowledge of your GreggPress site. Please contact support if you require any assistance with the troubleshooting process.

Switching to a default theme

The theme of your website is the first and easiest item to check. Replace the active theme on your site with a default theme (such as twentytwentyone) and recheck the server caching. You can download and activate default themes from the wp-admin page if you don’t have any already installed.

Disabling your plugins

After you’ve confirmed that the cache issues aren’t caused by the site’s theme, you should test your plugins. If any plugins known to create troubles with the server cache are installed on your site, Proxy Plugin Cache’s report output will identify them. Otherwise, follow the steps below to check the current plugins on your site.

Before making any changes, GreggHost recommends backing up your site’s database.

Except for Proxy Cache Purge, disable all plugins. Then, to see if server caching is working, restart the plugin’s caching test.

If removing plugins restores your site’s caching service, this indicates that a plugin is the most likely source of the cache difficulties. If you disabled many plugins, though, you’ll need to perform more testing to figure out which ones are to blame. To test the site’s plugins individually, follow the steps below.

One by one, enable your installed plugins, rerunning the cache test after each. To avoid viewing cached results, make sure you clean your site’s cache after each test.
Continue until the cache test gives the message “unable to cache site,” indicating the malfunctioning plugin. This plugin should be turned off.
Rerun the test after enabling any remaining disabled plugins. If the cache test continues to show problems, it’s possible that many plugins are to blame. Continue debugging until any plugins that are interfering with the server cache function of the site are disabled.
If any of the disabled plugins are required for your site’s intended operation, you must contact the plugin developer to discover a workaround or a way to work with the cache.

Remove the contents of your./wp-content/cache folder if your site uses any additional caching plugins.

Checking your plugins and themes using SSH
There are a couple of commands you can run from your website directory to assist limit down the list of plugins and

Checking your plugins and themes using SSH

To check your plugins for possibly dangerous code, run the following command:

./wp-content/plugins/grep -Rilon -P ‘(?:PHPSESSID|session start|start session)’ [server]$ grep -Rilon -P ‘(?:PHPSESSID|session start|start session)’
To check the code of your theme, run the following command:

./wp-content/themes/grep -Rilon -P ‘(?:PHPSESSID|session start|start session)’
Multiple false positives, such as the Proxy Cache Purge plugin, are possible. Using the procedures in the previous sections of this article, test any other plugins or themes that appear in the results.

Testing your .htaccess

If your server caching is still not working after disabling your plugins and switching to a default theme, you should disable your site’s.htaccess file. Rename your.htaccess file to.htaccess.off and create a new.htaccess file using the typical WordPress code via FTP or SSH.

Some plugins may add harmful lines to your site’s.htaccess file automatically. Two SSH commands to check for code that may clash with the server cache are listed below:

grep -r no-cache [server]$ wp-content/*
$ grep -r age=0 [server] wp-content/*
Test your site’s cache once you’ve put up the default.htaccess. If the default.htaccess coding doesn’t resolve your caching issue, the problem is most likely the custom code on your domain. Any custom material should be checked with your developer first.

Temporarily bypassing the GreggPress cache

The ‘Development Mode’ feature of the Proxy Cache Purge plugin lets you to temporarily bypass caching for all visitors. This stops your WordPress site’s visitors from viewing any old cached information. If your site is still under construction or if you are making significant design modifications, you might find this beneficial. In addition, if you’re having trouble with a theme or plugin, your developer can suggest that you try removing the cache for more testing.

Your site will operate slower if Development Mode is activated, so use it with caution.

This function can be enabled for up to 24 hours before it automatically deactivate. When you’ve finished making modifications or testing, you can manually switch off Development Mode before the 24-hour period has passed. When you disable Development Mode, GreggPress resumes caching, which reduces the page loading time for your visitors.

To turn off caching (enable Development Mode), do the following:

Open your GreggPress site’s WP-Admin dashboard page (example.com/wp-admin).
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In the left pane of your WP-Admin dashboard, go to ‘Proxy Cache > Settings’:
The page for Proxy Cache Purge Settings appears:
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Check the Activate Development Mode checkbox under the Development Mode Settings section.
Save your changes by clicking the Save Settings button.
On the settings page, you’ll see the following confirmation message:
2018-10 wp-admin proxy cache 06.fw.png
You may also check the Cache status in the WP-Admin toolbar at the top to see if the built-in server cache is active:
2018-10 wp-admin proxy cache 07.fw.png
Development Mode is active for 24 hours, after which it is turned off and normal caching continues. On the same page, you can disable Development Mode manually by going back to the ‘Settings’ page and unchecking the Development Mode checkbox, then saving it.

When would I need to purge my cache?

Because the old version of your site is cached, when you make changes to your site, such as altering or adding new material, the new changes may not appear live right away. Purging your cache can assist in pushing your modifications live so that visitors view the most up-to-date version of your website.

Manually purging the cache via the plugin

A ‘Purge Cache’ button is located in the WP-Admin toolbar at the top of the Proxy Cache Purge plugin:

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The ‘Purge Cache (All Pages)’ button deletes the entire cache. USE CAREFULLY—the entire purpose of caching is to cache.

When the changes aren’t showing up, a better option is to carefully clear the cache of a single item that you updated. When viewing the live page, use the plugin’s Purge Cache button to clear the cache of a post or page.

To clear the cache for a specific post or page, follow these steps:

Make sure you’re logged into your site’s WP-Admin.
Fill in the URL of the page or post you’d like to clear from your cache. To open the URL, click the View link under the title of a post or page in WP-Admin.
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Hover over the Cache button in the WP-Admin toolbar at the top of the page and pick Purge Cache (This Page) from the dropdown menu options.
The post or page gets removed from cache once the page reloads.

If you need to purge specific files, such as CSS that you manually altered and uploaded over SFTP/SSH, you’ll have to do so using SSH for the time being.

Manually purging the cache via SSH

To manually clear the GreggPress cache, make sure the GreggPress user is a shell account and log into your domain via SSH using the WP-CLI command-line tool.

An example command for purging a single CSS file is as follows:

$ wp varnish purge [server] https://example.com/wp-content/themes/mytheme/style.css
If you’re making changes to your theme files or updating several themes, the following is a quick way to clean your cache of all theme files:

$ wp varnish purge [server] —wildcard https://example.com/wp-content/themes/