Increase web application stack security (LAMP virtualization, step 3/6)

Setting up a memcached caching server

Let's move on to the third practical lesson of the series and talk about setting up a Memcached server.

Memcached can speed up your work with dynamic website databases. It should be deployed in a trusted network, where vm01 and vm02 clients can freely connect to our server. You will need to enter the following commands on vm03 with the IP address 192.168.1.12 .

Install Memcached server on vm03

Enter the following yum-manager command to install a memcached server on RHEL-like operating systems:

# yum install -y memcached

Installing the Memcached client on vm01 and vm02

You may need to install one of the following packages on the vm01 and vm02 virtual machines (php5 + Apache / Lighttpd server):
')

Perl-Cache-Memcached: Perl client (library) to work with Memcached server.
Python-Memcached: Python client (library) to work with Memcached-server.
PHP-PECL-Memcache: PHP extensions for working with the Memcached server.

Memcached setup

Edit the configuration file / etc / sysconfig / memcached by entering the following command:

 # vi /etc/sysconfig/memcached

Setup Example:

 PORT="11211"; USER="memcached"; MAXCONN="1024"; CACHESIZE="512"; ## make sure we accept connection from vm01 and vm02 on 192.168.1.12:11211 OPTIONS="-l 192.168.1.12 -L"

Save and close the file. Run the memcached server:

 # chkconfig memcached on # /sbin/service memcached start

Edit the configuration file / etc / sysconfig / iptables and make sure that only the virtual servers vm01 and vm02 have the appropriate rights to connect to our server:

 ##  tcp/udp  vm01 and vm02    memcached- ## -A INPUT -m state --state NEW -s 192.168.1.10 -m tcp -p tcp --dport 11211 -j ACCEPT -A INPUT -m state --state NEW -s 192.168.1.11 -m udp -p udp --dport 11211 -j ACCEPT -A INPUT -m state --state NEW -s 192.168.1.10 -m udp -p udp --dport 11211 -j ACCEPT -A INPUT -m state --state NEW -s 192.168.1.11 -m tcp -p tcp --dport 11211 -j ACCEPT

Save and close the file. Restart the iptables service with the following command:

 # /sbin/service iptables restart # /sbin/iptables -L -v -n

Increasing the limits of file descriptors and ports on vm03

For loaded memcached servers, increase the number of file descriptors and IP ports :

 #     fs.file-max = 50000 #   IP- net.ipv4.ip_local_port_range = 2000 65000

Apply the sysctl command so that the changed parameters of the Linux kernel take effect:

 # sysctl -p

Materials on the topic:

Source: https://habr.com/ru/post/148488/

All Articles