Shulou(Shulou.com)06/02 Report--

Because the program access of a web site has local characteristics: time locality: after a data has been accessed, it may be accessed again soon; spatial locality: when a data is accessed, the surrounding data may also be accessed; varnish can cache this part of the data.

Cached data with frequently accessed data can be called a hot spot: caches are also localized; timeliness: if cache space is exhausted: use LRU, the least recent use of algorithms; clean up expired caches

The basic working principle of varnish:

Varnish caches the data that can be cached in a way similar to the HTPP reverse proxy, and responds directly to the cached data to the client.

Without the corresponding data, it will point the request to the back-end machine and get the response data to respond to the client.

When the varnish has a cache, the response usually takes only a very short time, which is usually several orders of magnitude faster than directly accessing the back-end machine, so cache the cacheable pages into the varnish as much as possible.

Varnish working model diagram:

The processing mechanism diagram of varnish:

Which data can be cached or not cached: 1. Try to cache the public data of the site; 2. Use to exclude the user's private data.

Configure a wordperss site to use the varnish cache server and do static and dynamic separation

Basic Topology Diagram:

Varnish configuration (based on cenots7, the whole configuration process should avoid the influence of iptables and selinux): ntpdata 172.16.0.1 synchronization time

Install the varnish program:

Yum install varnish

Edit the main configuration file for varnish:

Vim / etc/varnish/varnish.params add the last line: DAEMON_OPTS= "- p thread_pools=3-p thread_pool_min=5-p thread_pool_max=1000-p thread_pool_timeout=300"

Start the varnish program:

Systemctl restart varnish

Edit the vcl configuration file for varnish:

Vim / etc/varnish/default.vcl

Make the following basic configuration:

Vcl 4.0th # Default backend definition. Set this to point to your content server.backend default {.host = "192.168.5.109"; .port = "80";} backend nginxsrvs {.host = "192.168.5.108"; .port = "80";} sub vcl_recv {# Happens before we check if we have this in cache already. # # Typically you clean up the request here, removing cookies you don't need, # rewriting the request, etc. If (req.method = = "PURGE") {return (purge);} if (req.url ~ "(? I) ^ / (login | admin)") {return (pass) } if (req.url ~ "(? I)\. (html | htm | css | svg | js | jpg | jpeg | png | gif | pdf)") {set req.backend_hint = nginxsrvs;} else {set req.backend_hint = default;} sub vcl_purge {return (synth (200, "Purged")) } sub vcl_deliver {if (obj.hits > 0) {set resp.http.X-Cache = "HIT via" + server.ip } else {set resp.http.X-Cache = "Miss via" + server.ip;}

Compile and load the default.vcl file into the varnish program:

Varnishadm-S secret enters the cli interface of varnish configuration to perform compilation loading: vcl.load test1 default.vcl vcl.use test1 quit configuration apm dynamic server: yum install httpdmkdir-p / apps/data (permissions need to be considered)

Cp the source file of wordpress to the directory

Edit the site profile for httpd

Vim / etc/httpd/conf.d/wordpress.conf

DirectoryIndex index.php index.html ServerName www.abc.com DocumentRoot / apps/data/wordpress Options FollowSymLinks AllowOverride None Require all granted

Start the httpd program:

Systemctl restart httpd configuration nfs service is used to share website files yum install nfs-utilsvim / etc/exports/apps/data * (rw,all_squash,anonuid=48) configure nginx static server: yum install nginx # the official yum source provided by nginx is used here

Configure the / etc/nginx/conf.d/default.conf file with the following modifications

Vim / etc/nginx/conf.d/default.conflocation / {root / apps/data/wordpress; # indicates the path to the web program index index.html index.htm;}

Start the nginx service program

Systemctl restart nginx

Change the hosts file to do the access test.

The basic configuration implementation of varnish has been completed.

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