Free tools Windows power users keep installed
One-click scans. No signup required.
iTechGuides is reader-supported. When you buy through links on our site, we may earn an affiliate commission. As an Amazon Associate I earn from qualifying purchases. Learn more
Antihost offers managed WordPress hosting with free migration, one-click staging and a 14-day free trial.
Installing the memcached service is only the first half of this job. A working WordPress setup needs four separate pieces: the Memcached daemon, the PHP extension loaded by the web server’s PHP runtime, one compatible persistent object-cache drop-in, and a WordPress configuration that points the drop-in at the daemon. Defining WP_CACHE alone does not make the cache persistent.
This guide covers Ubuntu servers running Apache or Nginx with PHP-FPM, shows how to check each layer, explains the difference between the memcache and memcached PHP extensions, and gives recovery steps for the errors that most often prevent activation.
What you are installing
Memcached is an in-memory key-value service. WordPress can use it for persistent object caching, so database query results and other objects can survive from one PHP request to the next. The service does not cache pages by itself and does not alter WordPress application behavior until a compatible object-cache implementation connects to it.
Keep these layers separate while troubleshooting:
| Layer | Purpose | How you verify it |
|---|---|---|
| Memcached daemon | Listens for cache requests, normally on 127.0.0.1:11211. |
systemctl is-active memcached and a listening-socket check. |
| PHP extension | Provides PHP classes and functions that can talk to Memcached. | Check the PHP runtime used by Apache or PHP-FPM, not only the command-line binary. |
| WordPress drop-in | Replaces WordPress’s request-scoped object cache with a persistent implementation. | Exactly one wp-content/object-cache.php file and a successful object-cache status in WordPress. |
| WordPress configuration | Defines the endpoint and, when needed, a site-specific key namespace. | Inspect the selected implementation’s settings and WordPress Site Health. |
Memcached’s own documentation cautions that installing the daemon does not automatically accelerate an application; the application must be programmed to use it. WordPress’s built-in object cache is request-scoped unless a persistent cache plugin or drop-in is installed.
#1 Best Overall
- Powerful Turbo Fan:CAGIWIRU Electric Air Duster have reached speed up to 130000RPM,Can efficient remove dust and debris.With LED light and Three Adjustable Speed to meet with different cleaning tasks.
- With Attached USB C Fasting Charging cable.Charing 3 hours,Enjoy up to 240 minutes of use on the lowest setting, For third speed can use for 25mins.with four charging options to meet with your needs.
- Wide Application: attached 5 different nozzles,making it suitable for a variety of scenes, such as car,pet, pc, keyboards, and other electronic devices. It also serves for office and home clean duster.
- Handy Design & Portable:Cordless air duster electric nozzle is Light weight and small size, design and comfortable to hold and space saving, convenient to carry around. You can put it in your room or inside the car without taking up space.
- Economical &Reusable: Built durable materials with a long-lasting battery,our CAGIWIRU air duster it's a sustainable alternative to disposable air cans.
Before you install: identify Ubuntu and the web PHP version
Ubuntu package names and PHP module paths vary by release. More importantly, the PHP binary at a shell prompt may not be the PHP runtime serving your site. Check both before choosing a package.
- Display the operating-system release with
cat /etc/os-releaseorlsb_release -a. - Check the command-line PHP version with
php -v. This is useful, but it is not proof that the web server uses the same version. - For PHP-FPM, list installed services with
systemctl list-units --type=service 'php*-fpm.service', then inspect the service that your virtual host uses, such asphp8.2-fpm. - For Apache, check whether the site uses an Apache PHP module with
apachectl -M | grep php. An Apache module and PHP-FPM can be different versions on the same machine. - Confirm the web runtime by opening WordPress’s Tools → Site Health → Info screen, or by temporarily placing a protected PHP diagnostic file containing
<?php phpinfo();in the site’s document root. Remove that file immediately after checking the PHP version and loaded modules.
Use the PHP version reported by the web runtime when installing the extension. A module loaded by the CLI binary does not help a PHP-FPM pool running another version.
Install and start the Memcached daemon
On Debian and Ubuntu, the Memcached project recommends installing the distribution package rather than compiling the daemon for a normal server deployment.
- Refresh package metadata:
sudo apt-get update. - Install the service:
sudo apt-get install memcached. - Enable it at boot and start it now:
sudo systemctl enable --now memcached. - Check the service state:
sudo systemctl status memcached --no-pager. The state should beactive (running). - Confirm the listening address and port with
sudo ss -ltnp | grep 11211. A local installation should normally show127.0.0.1:11211or another deliberately chosen private address.
Ubuntu’s package contents change as security updates are published. The Ubuntu 22.04 package index listed memcached 1.6.14-1ubuntu0.3, while Ubuntu 24.04 (Noble) listed 1.6.24-1ubuntu0.3 when checked on 2026-10-15. Treat those as repository observations, not permanent version guarantees.
Keep a single-host daemon private by default
Open /etc/memcached.conf and review the bind address, port, memory limit, and connection settings. For a WordPress and Memcached service on the same server, bind to localhost. Do not expose port 11211 to the public internet. If another private host must connect, bind only to the required private interface and enforce firewall rules, security-group rules, and network segmentation for the exact application hosts.
After changing the configuration, restart and recheck the socket:
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
Rank #2
- Screen Cleaner is Your Screen’s New Bestfriend! - EVEO is proud to present a screen cleaner that’s perfectly suited for your TV. Meet your new screen cleaner, computer screen cleaner, laptop cleaner, iPad cleaner, Macbook,tv cleaner or any other electronic device. Our screen cleaner spray and wipe along with the included plush microfiber cloth, easily removes dust, fingerprints & other smudges on the screen’s surface. Clean effectively for a streak-free screen
- Gentle on your Screens - Our screen cleaner spray and wipes is compatible to be used even for the most sensitive LCD, LED, CRT, and OLED screens in proper use. Be at ease knowing that this product is compatible with all the major brands: LG, SONY, Samsung, Sharp, iPad, iPhone, Android screens, Kindle, PC monitors - we’ve got you covered! Can be used as LCD screen cleaner, tv cleaner, smart tv screen cleaner, and more
- Premium Super Soft Plush Microfiber Cloth - Included in this efficient screen cleaning kit. This screen cleaner spray and wipe has our signature plush microfiber cloth specially designed to comply with screens and monitors and leave them streak-free. Has been shown to effectively absorbs stubborn stains, zero streaks, and no fiber shedding. Always use this together with our screen cleaner for the best results
- Easy-to-Use Screen Cleaner Kit + microfiber cleaning cloth - The EVEO Screen Cleaning Kit will easily be your new favorite tool when it comes to taking care of the things you love most, quick and easy solution for a streak-free screen. Simply screw on the sprayer gun on the screen cleaner bottle. Spray the cleaning liquid onto the microfiber cloth, then wipe the screen until desired cleanliness & shine is achieved.
- Quality Screen Care Kit Worth Purchasing - Enjoy a convenient Screen Cleaner anytime, anywhere you need it. Your satisfaction is our top priority. We stand behind the quality of our products and that’s why, you shouldn’t be worrying at all. We manufacture the Best Screen Cleaner. and can be used for laptop cleaning kit, laptop screen cleaner, tv screen cleaner for smart tv. MacBook screen cleaner, monitor cleaner or screen cleaner spray for electronic devices with microfiber cleaning cloth
sudo systemctl restart memcached
sudo systemctl is-active memcached
sudo ss -ltnp | grep 11211
Install the PHP extension that matches your web PHP
Ubuntu’s current package naming uses php-memcached as the general package, with release-specific packages such as php8.2-memcached available in package indexes. Install the package corresponding to the PHP version serving the site:
sudo apt-get install php-memcached
If your repository provides versioned packages and your site runs a specific PHP release, use that release explicitly, for example:
sudo apt-get install php8.2-memcached
Use apt-cache policy php-memcached php8.2-memcached to see which names exist on your Ubuntu release. The Ubuntu 22.04 index listed php-memcached 3.1.5+2.2.0-14.1; Ubuntu 24.04 listed 3.2.0+2.2.0-4ubuntu3 on 2026-10-15. Repository versions can change.
Quick wins for a faster PC:
Scan for outdated or missing drivers - takes under a minuteDriver Scan →Clear out junk files and repair common Windows errorsFree Scan →Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →Restart the PHP handler
Installing a package does not reload already-running workers. Restart the handler that actually serves the site:
- PHP-FPM example:
sudo systemctl restart php8.2-fpm - Apache with a loaded PHP module:
sudo systemctl restart apache2 - Nginx: restart the matching PHP-FPM service; restarting Nginx alone does not reload PHP-FPM workers.
Check the command-line module as an initial diagnostic with php -m | grep -i memcached and php --ri memcached. Then repeat the check from the web runtime using Site Health or a temporary diagnostic page. If the CLI reports the module but the web runtime does not, install the module for the web PHP version and restart that version’s handler.
Rank #3
- 【Large size】：Measuring 800 x 300 mm/ 31. 5×12 inches, which is wider and taller than others. Large mouse pad can perfectly fit your keyboard and mouse of any size, and there is also ample space for peripherals such as phones, tablets, etc.
- 【LED backlight mouse pad】：Blade Hawks RGB mouse pad provides 7 static modes and 7 dynamic modes will give you the options you are looking for. Power-off memory function remembers the last lighting mode you selected. The super glow fiber Chroma will give you a colorful gaming setup that you want.
- 【Anti-slip rubber base】：Made from Natural rubber, this gaming mousepad will firmly grip your desktop, allowing you to enjoy the ultimate precision in the games you are most passionate about. It also comes with a texture that enhances this ability even further.
- 【Smooth and waterproof surface】: Micro-textured cloth surface, for extremely precise mouse control and a smooth movement. When liquid splashes on the gaming mouse pad, it forms water droplets and slides down. Will not delay your work or gameplay.
- 【Plug and play】: This mouse and keyboard pad is powered by USB, plug and play, no driver required. One button control light modes. Press one time to change the lighting mode, press twice to change the brightness, press and hold about 3 seconds turn ON/OFF.
Understand memcache versus memcached
These are different PHP extensions with different APIs and class names:
| Extension | Typical PHP class | Compatibility implication |
|---|---|---|
memcache |
Memcache |
Legacy PECL extension. A drop-in that requires it will not be satisfied by installing only php-memcached. |
memcached |
Memcached |
PECL extension built around libmemcached. Ubuntu’s current package index names the package php-memcached. |
The names are not interchangeable. If WordPress reports Class Memcached not found, it needs the memcached extension in the web runtime. If a particular drop-in documents the PECL memcache extension, install that extension or choose another implementation whose requirements match the module you already run. Do not select a drop-in merely because both products contain the word “Memcached.”
Do these 3 things before closing this tab:
1Scan for outdated or missing drivers - takes under a minute2Repair Windows errors before they cause bigger problems3Fix the driver behind crashes, sound loss and screen glitchesInstall one persistent WordPress object-cache implementation
WordPress does not become persistent when you add define( 'WP_CACHE', true );. The WordPress Developer Resources reference states that the define has no effect unless a persistent cache plugin is installed. The daemon and PHP extension are prerequisites; the drop-in is what makes WordPress call them.
Choose one implementation and check its requirements before copying files:
| Decision point | Manual drop-in approach | Installer with readiness checks |
|---|---|---|
| Installation | Obtain the implementation’s object-cache.php, copy it into wp-content, and apply its documented endpoint settings. |
Use the WordPress dashboard or installer supplied by the implementation; let it discover or save the host and port. |
| Extension compatibility | You must verify whether the file expects memcache or memcached. |
The installer may test the available class and report a mismatch before activation. |
| Existing drop-in | Inspect and replace an old file deliberately. | Readiness checks can refuse activation when a foreign object-cache.php already exists. |
| Configuration | Set the endpoint and any key-salt option exactly as documented by that implementation. | Choose automatic discovery or save the host and port in its settings. |
| Fallback and observability | Review the implementation’s diagnostics and behavior when the daemon is unavailable. | Use its status screen, logs, and health checks, then confirm the result in WordPress Site Health. |
Manual drop-in installation
- Back up the current
wp-contentdirectory and database. - Inspect whether
wp-content/object-cache.phpalready exists:ls -l /var/www/example.com/wp-content/object-cache.php. - Read the selected implementation’s compatibility notes. In particular, confirm the PHP extension class it calls and whether it supports your WordPress version and multisite arrangement.
- Copy its single
object-cache.phpfile into the site’swp-contentdirectory, for example:sudo cp object-cache.php /var/www/example.com/wp-content/object-cache.php. - Set the server endpoint using that implementation’s documented configuration mechanism. The standard local endpoint is
127.0.0.1:11211. - If several WordPress sites share one daemon, set a unique
WP_CACHE_KEY_SALTfor each site. Without separate namespaces, identical cache keys from different sites can collide. - Set ownership and permissions so the web user can read the drop-in, while keeping
wp-config.phpas restrictive as your PHP-FPM and deployment model permits. Do not make the entire WordPress tree world-writable.
Do not copy two object-cache files under different names and assume WordPress will choose correctly. WordPress loads the file specifically named wp-content/object-cache.php; that file must have one clear owner.
Dashboard or maintained-installer approach
An installer that performs readiness checks can be safer for administrators who do not want to edit files manually. Run its checks after the daemon and PHP extension are installed. Choose automatic discovery only when the daemon is local and listening on the expected address; otherwise save the deliberate host and port. If the installer reports an existing foreign drop-in, stop and inspect it rather than forcing activation. Remove or replace the stale file only after confirming which implementation should remain.
The Tool Desk
Outbyte PC Repair FREERepair Windows errors before they cause bigger problemsFix Now →Outbyte Driver Updater FREEScan for outdated or missing drivers - takes under a minuteDriver Scan →Rank #4
- 【Softer and More Comfortable】Vaydeer wrist rest has unique diamond pattern, which is the combination of softness and aesthetics. The materials of wrist rest are improved into higher quality memory foam and covered with silky smooth lycra. The computer wrist rest makes you as comfortable and cushiony as like rest your wrists on clouds.
- 【Ergonomic Wrist Saver】The wrist rests for keyboard and mouse comes with a 17.32×3.15×0.83 inch keyboard wrist pad and a 5.94×3.15×0.83 inch mouse wrist support. Based on ergonomic design, the unique concave shape is the perfect fit for your wrist joints. The wrist rest pad fits most computer keyboards and laptops, improve hand and wrist posture, release your wrist and arm stress.
- 【Non-Slip Rubber Bottom】Featuring an anti-skid silicone base on the bottom, this wrist keyboard support stays firmly in place on your desk, preventing the padding from sliding around, ensuring stable and consistent wrist support during extended computer sessions.
- 【Better Experience & Pain Relief】Our keyboard arm rest is beneficial to alleviate the soreness caused by direct contact and friction between your arm and a hard desk surface, reducing the risk of wrist fatigue or carpal tunnel. The soft texture of memory foam can evenly distribute the pressure around your wrists and provide good support with just enough give.
- 【Helpful in Multiple Scenarios】Whether you're working, studying, writing, typing, gaming, this keyboard and mouse rest combo is an essential accessory to add comfort and support to your hands and wrists. It’s also a great gift for men, women, family, friend, coworker, gamer, teacher, etc.
Configure WordPress and verify every layer
Use this order so a failure is easy to localize.
- Daemon: run
sudo systemctl is-active memcachedand verify the expected listening address withsudo ss -ltnp | grep 11211. - Web PHP: confirm the web-serving runtime exposes the required class. A command-line result from
php -mis insufficient when PHP-FPM uses another version. - Drop-in: run
ls -l wp-content/object-cache.phpfrom the WordPress root. There should be exactly one active file at that path; inspect its owner and modification time if a plugin reports a conflict. - WordPress: open Tools → Site Health → Status and look for the Persistent object cache check. It should report that a persistent object cache is in use, not merely that the
WP_CACHEconstant is defined. - Optional WP-CLI check: from the site root, run
wp cache typeif WP-CLI is installed. You can also evaluatewp_using_ext_object_cache()withwp eval 'var_export( wp_using_ext_object_cache() );'. - Application behavior: exercise normal logged-out pages and review the implementation’s diagnostics or logs. A running daemon with no requests from WordPress indicates a drop-in, extension, endpoint, or permissions problem.
Interpret the result instead of relying on one signal
A green service status proves only that the daemon started. A loaded PHP module proves only that PHP can instantiate its client class. Site Health proves that WordPress recognized a persistent object-cache drop-in, while implementation diagnostics show whether requests are reaching the configured host and port. Check all four signals after installation and again after PHP or Ubuntu upgrades.
When testing, make one controlled change at a time. First establish that the local socket is listening, then confirm the PHP class, then activate the drop-in, and finally reload Site Health. This sequence prevents a dashboard error from being misdiagnosed as an Ubuntu service failure. If you use a remote endpoint, record the exact hostname or address and port in the implementation settings so a later administrator can compare it with firewall and daemon configuration.
Choosing between implementations
Compatibility is the first criterion: match the drop-in to the class exposed by your installed extension. Next compare how each implementation is installed and configured. A manual drop-in gives direct control over the file and endpoint but requires you to inspect ownership, permissions, and replacement steps. A maintained installer can perform readiness checks, discover a local service, expose status information, and refuse to overwrite a foreign drop-in.
Also check host and port controls, multisite behavior, key-salt support, observability, and fallback behavior. For a shared Memcached service, per-site key salts are essential. For a remote service, the implementation must let you specify the deliberate private address rather than silently assuming localhost. If the daemon becomes unavailable, understand whether the implementation reports an error, falls back to nonpersistent caching, or leaves WordPress requests failing; that behavior should be part of your outage plan.
Troubleshooting common failures
“Class Memcached not found” or “PHP extension missing”
- Check the PHP version shown by the web runtime, not just
php -v. - Install the matching
php-memcachedor versionedphp8.x-memcachedpackage. - Restart the matching PHP-FPM or Apache handler.
- Confirm that the selected drop-in expects
Memcached, not the legacyMemcacheclass.
Connection refused or timeout
- Verify that
memcachedis active and listening. - Compare the drop-in’s configured host and port with the daemon’s bind address.
127.0.0.1is not interchangeable with a remote hostname. - For a remote daemon, check host firewalls, cloud security groups, routing, and the daemon’s bind interface. Permit only the required application hosts.
- Check service logs with
sudo journalctl -u memcached -bfor startup or configuration errors.
“Another object-cache.php already exists”
List and inspect the existing file before activation. Keep one implementation only. Disable the old plugin or remove its drop-in according to its uninstall instructions, then install the replacement. Leaving a stale file in place can make a new installer appear broken even when the daemon and PHP extension are healthy.
No measurable performance change
Memcached installation alone changes nothing in WordPress. Confirm that Site Health reports a persistent object cache and that the expected drop-in is the file WordPress is loading. Also check whether you are testing logged-in requests, uncached administrative pages, or a site whose workload does not benefit from object caching. Do not treat a faster page as proof that the extension is correctly loaded; verify the status independently.
Best Value
- 【No Drill Mounted】Cable management tray can be assembled in as little as 3 minutes or less-simply. Side clips easily clampe the edge of desk, pass through the holes on the sides, and secure excess cables with baskets. Desk cable management supports inward or outward installation to meet your needs in different scenarios, and provides you with great convenience when collecting and organizing wires.
- 【Rubber Pad Protects Desk】Wire organizer under desk built-in soft rubber pads on the clamp protect your desk from scratches, so you will not damage your furniture or office.
- 【Sturdy and Beautiful】Cord management under desk is made of high-quality carbon steel and holds about 15 lbs. The wire basket has 2 holes on each side of the tray to enable your cables to pass freely. Cable baskets are suitable for desk thickness use from 0.4" to 2.4".
- 【Space Saving & Keep Organized】Desk cable management tray holds all your power cords, outlet strips, USB hubs and computer transformers hidden from your feet, and the data cables will not enter the vacuum cleaner to keep your desk clean and tidy. Desk wire organizer is also suitable for use in the kitchen and outdoors.
- 【Reduce Safety Risks】Cable tray under desk keeps all plugs away from your kids, no more worry about tripping. Using 2 holes wire tray saves extra space, helps you easily cabling and wire protection. The mesh design is not easy to accumulate dust, but avoids safety accidents caused by messy wires.
Operational and security considerations
- Use localhost binding for a same-server deployment whenever possible.
- Never expose an unauthenticated Memcached listener directly to the public internet.
- Give each site sharing a daemon a unique
WP_CACHE_KEY_SALT. - Monitor memory pressure, evictions, connection errors, and restart events using the daemon and drop-in’s available diagnostics.
- After PHP or Ubuntu upgrades, recheck the web PHP module, PHP-FPM service name, drop-in compatibility, and WordPress Site Health; package upgrades can change the active PHP version.
- Keep backups of
wp-config.php, the active drop-in, and deployment-specific permissions so you can roll back a failed cache change without taking the site offline.
Completion checklist
- Ubuntu release and web PHP version identified.
memcachedinstalled, enabled, running, and listening on the intended private address.- Matching PHP extension installed and visible to the web-serving runtime.
- One compatible persistent object-cache implementation installed.
- Only one
wp-content/object-cache.phpexists and owns the integration. - Endpoint set to
127.0.0.1:11211for a local daemon, or deliberately secured for a remote daemon. - Unique
WP_CACHE_KEY_SALTconfigured when sites share a service. - WordPress Site Health reports a persistent object cache.
Frequently Asked Questions
How do I install Memcached on Ubuntu for WordPress?
Install the daemon with sudo apt-get update and sudo apt-get install memcached, enable it with sudo systemctl enable --now memcached, then install the matching web-PHP package such as php-memcached. Restart PHP-FPM or Apache, install one compatible WordPress object-cache drop-in, and verify the service, PHP module, drop-in, and Site Health status.
How do I enable Memcached object caching in WordPress?
Installing the daemon or defining WP_CACHE is not enough. Install a persistent object-cache implementation that matches your PHP extension, place its single object-cache.php file in wp-content (or use its maintained installer), configure 127.0.0.1:11211 for a local service, and confirm that Site Health reports a persistent object cache.
What is the difference between the memcache and memcached PHP extensions?
They are separate extensions with different APIs and classes. The legacy memcache extension exposes Memcache; Ubuntu’s php-memcached package exposes Memcached and uses libmemcached. A drop-in must be compatible with the extension actually loaded by the web runtime.
Why does WordPress say the Memcached PHP extension is missing?
Usually the extension was installed for the CLI PHP version, while Apache or PHP-FPM runs another version. Check the web runtime, install its matching php-memcached or versioned package, restart the correct handler, and verify the required class from Site Health or a temporary diagnostic page.
Can multiple WordPress sites share one Memcached daemon?
Yes, but configure a unique WP_CACHE_KEY_SALT for every site. Separate namespaces prevent identical keys from different sites from colliding. Keep the daemon on a private interface and restrict network access to the application hosts.
What should I do if an installer says another object-cache.php already exists?
Inspect wp-content/object-cache.php and identify the implementation that owns it. Keep only one drop-in, following the old plugin’s uninstall instructions before removing or replacing the file. Do not force a second installer over an unknown drop-in.
The Bottom Line
For WordPress on Ubuntu, install and verify four distinct layers: the private Memcached daemon, the matching PHP extension used by the web runtime, one compatible object-cache.php drop-in, and the endpoint/key-salt configuration. A persistent cache is enabled only when WordPress recognizes that drop-in and Site Health confirms it.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
