Enterprise-level memcached deployment (session sharing) and memcachedsession

Enterprise-level memcached deployment (session sharing) and memcachedsession

Server deployment

First milestone: Install dependency

Memcache uses the libevent library for Socket processing.

[root@nfs01 ~]# yum install libevent  libevent-devel nc -y

Second milestone: Installing memcache

[root@nfs01 ~]# yum install memcached -y[root@nfs01 ~]# which memcached/usr/bin/memcached

Third milestone: Start memcachedService

[root@nfs01 ~]# memcached -m 16m -p 11211 -d -u root -c 8192[root@nfs01 ~]# lsof -i :11211COMMAND     PID USER   FD   TYPE DEVICE SIZE/OFF NODE NAMEmemcached 10796 root   26u  IPv4  85717      0t0  TCP *:memcache (LISTEN)memcached 10796 root   27u  IPv6  85718      0t0  TCP *:memcache (LISTEN)memcached 10796 root   28u  IPv4  85721      0t0  UDP *:memcachememcached 10796 root   29u  IPv6  85722      0t0  UDP *:memcache[root@nfs01 ~]# netstat -lntup |grep memcatcp        0      0 0.0.0.0:11211        0.0.0.0:*      LISTEN      10796/memcached    tcp        0      0 :::11211               :::*           LISTEN      10796/memcached    udp        0      0 0.0.0.0:11211      0.0.0.0:*                      10796/memcached    udp        0      0 :::11211                    :::*                    10796/memcached   

Note: memcachedYou can start multiple instances at the same time.

[root@nfs01 ~]# memcached -m 16m -p 11212 -d -u root -c 8192

The fourth milestone: Write Data to boot automatically

echo 'memcached -m 16m -p 11211 -d -u root -c 8192' >>/etc/rc.local

Client deployment(Web Server)

First milestone: Installing PHP memcacheExtension

The command set is as follows:

cd /server/toolswget http://pecl.php.net/get/memcache-2.2.7.tgztar xf memcache-2.2.7.tgzcd memcache-2.2.7/application/php/bin/phpize./configure -enable-memcache --with-php-config=/application/php/bin/php-configmake && make install

Complete operation process:

[root@web01 ~]# cd /server/tools/[root@web01 tools]# wget http://pecl.php.net/get/memcache-2.2.7.tgz[root@web01 tools]# tar xf memcache-2.2.7.tgz[root@web01 tools]# cd memcache-2.2.7[root@web01 memcache-2.2.7]# /application/php/bin/phpizeConfiguring for:PHP Api Version:         20121113Zend Module Api No:      20121212Zend Extension Api No:   220121212[root@web01 memcache-2.2.7]# ./configure -enable-memcache --with-php-config=/application/php/bin/php-config[root@web01 memcache-2.2.7]# make && make install

Check whether the installation is successful

[root@web01 memcache-2.2.7]# ls -l /application/php/lib/php/extensions/no-debug-non-zts-20121212/total 252-rwxr-xr-x 1 root root 258048 Nov  7 10:03 memcache.so

Memcache. soIndicates that the plug-in is successfully installed.

Second milestone: Configuring memcacheMake the client take effect

[root@web01 memcache-2.2.7]# cd /application/php/lib/[root@web01 lib]# vim php.ini……[root@web01 lib]# tail -2 php.iniextension_dir = "/application/php/lib/php/extensions/no-debug-non-zts-20121212/"extension = memcache.so

Third milestone: Check the syntax and restart the service

[root@web01 lib]# /application/php/sbin/php-fpm  -t[07-Nov-2017 10:20:44] NOTICE: configuration file /application/php-5.5.32/etc/php-fpm.conf test is successful

#Restart service

killall php-fpmkillall php-fpm/application/php/sbin/php-fpm

BrowserAccessPhpinfoMemcache appears on the pageThe information indicates that the configuration is successful..

 

Fourth milestone: Write and test memcacheFile

[root@web01 blog]# cat  test_memcache.php<?php     $memcache = new Memcache;     $memcache->connect('172.16.1.31', 11211) or die ("Could not connect NFS server");     $memcache->set('key', 'Memcache connect OK');     $get = $memcache->get('key');     echo $get;?>

Memcache connect OKConnection successful

[root@web01 blog]# /application/php/bin/php   test_memcache.php Memcache connect OK

Fifth milestone: modifying phpConfiguration(Set sessionShare)

[root@web01 ~]# vim /application/php/lib/php.ini

Original configuration

session.save_handler = filessession.save_path = "/tmp"

To:

session.save_handler = memcachesession.save_path = "tcp://172.16.1.31:11211"

Restart the php service after modification.

killall php-fpmkillall php-fpm/application/php/sbin/php-fpm

Phpinfo before modificationInformation

After modification, phpinfoInformation

 

The enterprise-level memcache (session sharing) has been deployed.

1.1.1 Advantages and Disadvantages of Memcached in cluster session shared storage

Advantages:

1) reading/writing speed is much faster than normal file files.

2) It can solve the problem of multiple servers sharing sessions.

Disadvantages:

1) session data is stored in memory, which lacks persistence, but is not a problem for session data.

2) generally, it is a single node. If multiple nodes are deployed, data cannot be synchronized between multiple nodes. The hash algorithm still causes session loss.

Alternative solution:

1) You can use another persistent system to store sessions, such as redis and ttserver, instead of memcached.

2) in high-performance concurrency scenarios, cookies are much more efficient than sessions. Therefore, large websites use cookies to solve session sharing problems.

3) Some bad Methods: lvs-p, nginx ip_hash, not recommended.

DedeCMS using memcache

Problem: After modifying the file, DedeCMS found that the background http://www.etiantia.org/dede could not be accessed

Solution:

Modify file 1:

[Root @ web01 include] # pwd/application/nginx/html/www/include [root @ web01 include] # vim common. inc. php135 // Session storage path 136 $ enkey = substr (md5 (substr ($ pai_cookie_encode, 137),); // $ sessSavePath = DEDEDATA. "/sessions _ {$ enkey}"; 138 $ sessSavePath = "tcp: // 172.16.1.31: 11211"; 139 if (! Is_dir ($ sessSavePath) mkdir ($ sessSavePath );

Modify file 2:

[root@web01 include]# vim vdimgck.php24 $enkey = substr(md5(substr($cfg_cookie_encode,0,5)),0,10);25 //$sessSavePath = DEDEDATA."/sessions_{$enkey}";26 $sessSavePath = "tcp://172.16.1.31:11211";27 if ( !is_dir($sessSavePath) ) mkdir($sessSavePath);

Let DedeCMS directly use memcache sharing to solve the problem.

Special thanks:Yuan Fang