Tag: memcached

Install Memcached on cPanel Server
Login to WHM as user root, go to Terminal or login to SSH as user root. Then run the command
```
yum install memcached
```
Enable memcached to start on boot.
```
systemctl enable memcached
```
Configure memcached

Default configuration on AlmaLinux 9 look like the following
```
PORT="11211"
USER="memcached"
MAXCONN="1024"
CACHESIZE="64"
OPTIONS="-l 127.0.0.1,::1"
```
edit configuration file
```
vi /etc/sysconfig/memcached
```
Lets change cache size to 128 mb

Find
```
CACHESIZE="64"
```
Replace 64 with 128

In AlmaLinux 9, memcached only listen on loop back interface IP address (127.0.0.1,::1). If your configuation don’t restrict memcache to listen to 127.0.0.1, change your options line as follows.
```
OPTIONS="-l 127.0.0.1 -U 0"
```
This will restrict memcached to listen on IP address 127.0.0.1 and -U 0 disable UDP. This is done to protect memcachd installation from attacks.

Restart memcached with
```
systemctl restart memcached
```
To verify memcached is running, run
```
[root@server1 ~]# netstat  -lntp | grep memc
tcp        0      0 127.0.0.1:11211         0.0.0.0:*               LISTEN      2224258/memcached   
[root@server1 ~]# 
```
We have memcached listening on 127.0.0.1:11211

Now we have memcached deamon running. We need PHP module installed.

Installing memcached PHP module

To list all available memcached PHP module, run
```
yum search php-memcached
```
To install memcache module for PHP 8.2, run
```
yum install -y ea-php82-php-memcached
```
For PHP 8.0, install package ea-php80-php-memcached, similarly, for PHP 8.1 install ea-php81-php-memcached.

If you use CloudLinux PHP selector, memcached is already installed on the system. You can enable the module using PHP Selector.

Back to memcached
December 19, 2023

How to run multiple memcached instances

I had copied a PrestaShop site to another domain. Both domains are on same server, using same Memcached server for caching. When i visit one of the site, resources like css/js files are loading from other website. To fix this, i configured 2 Memcached servers running on 2 different ports, each site use its own Memcached instance.

On Ubuntu server, i installed memcached and supervisor with

apt install -y memcached memcached

Create file

vi /etc/supervisor/conf.d/memcached.conf

Inside add

[program:memcached2]
priority=200
command=/usr/bin/memcached -m 64 -p 11212 -u memcache -l 127.0.0.1 -P /var/run/memcached/memcached2.pid
user=memcache
autorestart=true
autostart=true
redirect_stderr=true

By default Memcached runs on port 11211, above configuration will make an instance of Memcached that runs on port 11212.

If you want to create another instance of memcached, duplicate above lines, in the lines, change

[program:memcached2]

with

[program:memcached3]

Find

command=/usr/bin/memcached -m 64 -p 11212 -u memcache -l 127.0.0.1 -P /var/run/memcached/memcached2.pid

Replace port with different port, say 11213 and /var/run/memcached/memcached2.pid with /var/run/memcached/memcached2.pid

Here is the complete configuration with 2 Memcached instances running under supervisiord

[program:memcached2]
priority=200
command=/usr/bin/memcached -m 64 -p 11212 -u memcache -l 127.0.0.1 -P /var/run/memcached/memcached2.pid
user=memcache
autorestart=true
autostart=true
redirect_stderr=true

[program:memcached3]
priority=200
command=/usr/bin/memcached -m 64 -p 11213 -u memcache -l 127.0.0.1 -P /var/run/memcached/memcached3.pid
user=memcache
autorestart=true
autostart=true
redirect_stderr=true

Reload supervisor

supervisorctl reload

Check status

supervisorctl status

Here is an example with 4 memcached instances running

root@zen-keldysh:/etc/supervisor/conf.d# supervisorctl reload
Restarted supervisord
root@zen-keldysh:/etc/supervisor/conf.d# supervisorctl status
memcached_erikoisrahti           RUNNING   pid 337864, uptime 0:00:02
memcached_longdrink24            RUNNING   pid 337865, uptime 0:00:02
memcached_tulivesi               RUNNING   pid 337866, uptime 0:00:02
memcached_viskit                 RUNNING   pid 337867, uptime 0:00:02
root@zen-keldysh:/etc/supervisor/conf.d#

Here are the configuration file for above 4 Memcached instance setup

root@server1:~# cat /etc/supervisor/conf.d/memcached.conf 
[program:memcached_longdrink24]
priority=200
command=/usr/bin/memcached -m 64 -p 11212 -u memcache -l 127.0.0.1 -P /var/run/memcached/memcached2.pid
user=memcache
autorestart=true
autostart=true
redirect_stderr=true

[program:memcached_viskit]
priority=200
command=/usr/bin/memcached -m 64 -p 11213 -u memcache -l 127.0.0.1 -P /var/run/memcached/memcached-viskit.pid
user=memcache
autorestart=true
autostart=true
redirect_stderr=true

[program:memcached_erikoisrahti]
priority=200
command=/usr/bin/memcached -m 64 -p 11214 -u memcache -l 127.0.0.1 -P /var/run/memcached/memcached-erikoisrahti.pid
user=memcache
autorestart=true
autostart=true
redirect_stderr=true

[program:memcached_tulivesi]
priority=200
command=/usr/bin/memcached -m 64 -p 11215 -u memcache -l 127.0.0.1 -P /var/run/memcached/memcached-tulivesi.pid
user=memcache
autorestart=true
autostart=true
redirect_stderr=true

root@server1:~#

August 5, 2023

Enable memcached on Magento 2 in Plesk Server

To install memcached, run

apt install php-memcached
apt install build-essential
apt install autoconf automake gcc libmemcached-dev libhashkit-dev pkg-config plesk-php*-dev zlib1g-dev

Enable memcached php module

/opt/plesk/php/7.3/bin/pecl install memcached

This is for PHP 7.3, change the path to pecl for your version of PHP.

Activate memcached

echo "extension=memcached.so" > /opt/plesk/php/7.3/etc/php.d/memcached.ini

Update php handler

plesk bin php_handler --reread

Restart php-fpm

systemctl stop plesk-php73-fpm.service
systemctl start  plesk-php73-fpm.service

Install memcached deamon

apt install memcached

Restart memcached

systemctl enable memcached
systemctl restart memcached

Verify it is working with netstat

malta2032:~# netstat -lntp | grep mem
tcp        0      0 127.0.0.1:11211         0.0.0.0:*               LISTEN      30204/memcached     
malta2032:~#

Activate memcached in Magento 2

Edit file

vi app/etc/env.php

Find

    'session' => [
        'save' => 'files'
    ],

Replace with

    'session' => [
        'save' => 'memcached',
        'save_path' => '127.0.0.1:11211'
    ],

If you get error like

Warning: SessionHandler::read(): open(127.0.0.1:6379/sess_0s39482mnk2hhoflf4d6odjuv2, O_RDWR) failed: No such file or directory (2) in /vendor/magento/framework/Session/SaveHandler/Native.php on line 22

edit your php.ini and set “session.save_handler” from “files” to “memcached”.

See if memcached working

To see if memcached is caching, you can use

telnet 127.0.0.1  11211
stats items

To exit, type

quit

See Magento, Memcached

March 17, 2021

Secure Memcached on CentOS/RHEL 7
By default memcached on CentOS 7 is set to run on all IP address on the server. This allow attackers to abuse the service.

To set memcached to only listen to localhost (127.0.0.1), edit file
```
vi /etc/sysconfig/memcached
```
Find
```
OPTIONS=""
```
Replace with
```
OPTIONS="-l 127.0.0.1"
```
See memcached
October 13, 2018
Install memcached on CentOS 7
To install memcached on CentOS 7, run
```
yum -y install memcached
```
Set memcached to start on boot
```
systemctl enable memcached
```
Start memcached with
```
systemctl start memcached
```
Installing PHP Module

You need remi repository installed, which provide a memcached module for all versions of php they support.

For PHP 5.6, run
```
yum install php-memcache
```
Now phpinfo() will show
- Secure Memcached on CentOS/RHEL 7
- How to Install memcached on CentOS Plesk Server
See memcached
July 9, 2018

memcached

To see stats, run

[root@centos-1gb-nyc1-01 ~]# echo "stats settings" | nc localhost 11211
STAT maxbytes 67108864
STAT maxconns 1024
STAT tcpport 11211
STAT udpport 11211
STAT inter NULL
STAT verbosity 0
STAT oldest 0
STAT evictions on
STAT domain_socket NULL
STAT umask 700
STAT growth_factor 1.25
STAT chunk_size 48
STAT num_threads 4
STAT num_threads_per_udp 4
STAT stat_key_prefix :
STAT detail_enabled no
STAT reqs_per_event 20
STAT cas_enabled yes
STAT tcp_backlog 1024
STAT binding_protocol auto-negotiate
STAT auth_enabled_sasl no
STAT item_size_max 1048576
STAT maxconns_fast no
STAT hashpower_init 0
STAT slab_reassign no
STAT slab_automove 0
END
[root@centos-1gb-nyc1-01 ~]#

January 23, 2018

Tag: memcached

Install Memcached on cPanel Server

Configure memcached

Installing memcached PHP module

How to run multiple memcached instances

Enable memcached on Magento 2 in Plesk Server

Activate memcached in Magento 2

See if memcached working

Secure Memcached on CentOS/RHEL 7

Install memcached on CentOS 7

memcached