Category: Varnish Cache

Varnish is an open source web accelerator (also called a HTTP reverse proxy) designed for content-heavy dynamic web sites to speed up web server’s performance. Typical Web server will handles all the request and returning a response to the client. But with Varnish cache, it will serve the saved copy page instead of re-requesting the same revisited page from web server. This will reduced the server load and increased the response times. For those who plan to run a virtual private server (VPS) and also run a dedicated web server, hope that this article will help. This article will describe how to install and configure Varnish Cache with Apache on CentOS 6.5.

1. Setup varnish repo :

[root@centos6 ~]# wget http://repo.varnish-cache.org/redhat/varnish-3.0/el6/noarch/varnish-release/varnish-release-3.0-1.el6.noarch.rpm
[root@centos6 ~]# rpm --nosignature -i varnish-release-3.0-1.el6.noarch.rpm

2. Install Varnish and Apache :

[root@centos6 ~]# yum install varnish -y
[root@centos6 ~]# yum install httpd -y

3. Make both program start at boot :

[root@centos6 ~]# chkconfig --level 345 varnish on
[root@centos6 ~]# chkconfig --level 345 httpd on

4. Configure apache to listen to port 8080 :

[root@centos6 ~]# vi /etc/httpd/conf/httpd.conf

Modify below :

Listen 8080

5. Configuring Varnish Cache :

[root@centos6 ~]# vim /etc/sysconfig/varnish

..
..
# # Main configuration file. You probably want to change it :)
VARNISH_VCL_CONF=/etc/varnish/default.vcl
#
# # Default address and port to bind to
# # Blank address means all IPv4 and IPv6 interfaces, otherwise specify
# # a host name, an IPv4 dotted quad, or an IPv6 address in brackets.
# VARNISH_LISTEN_ADDRESS=
#VARNISH_LISTEN_PORT=6081
VARNISH_LISTEN_PORT=80
#
# # Telnet admin interface listen address and port
VARNISH_ADMIN_LISTEN_ADDRESS=127.0.0.1
VARNISH_ADMIN_LISTEN_PORT=6082
#
# # Shared secret file for admin interface
VARNISH_SECRET_FILE=/etc/varnish/secret
#
# # The minimum number of worker threads to start
VARNISH_MIN_THREADS=50
#
# # The Maximum number of worker threads to start
VARNISH_MAX_THREADS=1000
#
# # Idle timeout for worker threads
VARNISH_THREAD_TIMEOUT=120
#
# # Cache file location
VARNISH_STORAGE_FILE=/var/lib/varnish/varnish_storage.bin
#
# # Cache file size: in bytes, optionally using k / M / G / T suffix,
# # or in percentage of available disk space using the % suffix.
VARNISH_STORAGE_SIZE=1G
#
# # Backend storage specification
VARNISH_STORAGE="file,${VARNISH_STORAGE_FILE},${VARNISH_STORAGE_SIZE}"
#
# # Default TTL used when the backend does not specify one
VARNISH_TTL=120
#
# # DAEMON_OPTS is used by the init script.  If you add or remove options, make
# # sure you update this section, too.
DAEMON_OPTS="-a ${VARNISH_LISTEN_ADDRESS}:${VARNISH_LISTEN_PORT} \
             -f ${VARNISH_VCL_CONF} \
             -T ${VARNISH_ADMIN_LISTEN_ADDRESS}:${VARNISH_ADMIN_LISTEN_PORT} \
             -t ${VARNISH_TTL} \
             -w ${VARNISH_MIN_THREADS},${VARNISH_MAX_THREADS},${VARNISH_THREAD_TIMEOUT} \
             -u varnish -g varnish \
             -S ${VARNISH_SECRET_FILE} \
             -s ${VARNISH_STORAGE}"
#
..
..

Add the following in /etc/varnish/default.vcl :

[root@centos6 ~]# vim /etc/varnish/default.vcl

backend default {
  .host = "127.0.0.1";
  .port = "8080";
}

6. Start Varnish and Apache ”

[root@centos6 ~]# service varnish start
Starting Varnish Cache:                                    [  OK  ]
[root@centos6 ~]# service httpd start
Starting httpd:                                            [  OK  ]

7. verify varnish and Apache running on the correct port :

[root@centos6 ~]# netstat -plunt

Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address               Foreign Address             State       PID/Program name
tcp        0      0 0.0.0.0:111                 0.0.0.0:*                   LISTEN      1042/rpcbind
tcp        0      0 0.0.0.0:80                  0.0.0.0:*                   LISTEN      21729/varnishd
tcp        0      0 0.0.0.0:22                  0.0.0.0:*                   LISTEN      1075/sshd
tcp        0      0 127.0.0.1:6082              0.0.0.0:*                   LISTEN      21728/varnishd
tcp        0      0 :::111                      :::*                        LISTEN      1042/rpcbind
tcp        0      0 :::80                       :::*                        LISTEN      21729/varnishd
tcp        0      0 :::8080                     :::*                        LISTEN      1182/httpd
tcp        0      0 :::22                       :::*                        LISTEN      1075/sshd
udp        0      0 0.0.0.0:111                 0.0.0.0:*                               1042/rpcbind
udp        0      0 0.0.0.0:793                 0.0.0.0:*                               1042/rpcbind
udp        0      0 :::111                      :::*                                    1042/rpcbind
udp        0      0 :::793                      :::*                                    1042/rpcbind

8. Verify the Varnish by running the following command.

[root@centos6 ~]# curl -I http://www.ehowstuff.local
HTTP/1.1 200 OK
Server: Apache/2.2.15 (CentOS)
X-Powered-By: PHP/5.3.3
X-Pingback: http://www.ehowstuff.local/xmlrpc.php
Content-Type: text/html; charset=UTF-8
Content-Length: 7990
Accept-Ranges: bytes
Date: Sun, 13 Apr 2014 15:41:41 GMT
X-Varnish: 1889373153
Age: 0
Via: 1.1 varnish
Connection: keep-alive

9. ApacheBench performance test without Varnish Cache

[root@centos6 ~]# ab -k -n 1000 -c 50 http://www.ehowstuff.local:8080/
This is ApacheBench, Version 2.3 < $Revision: 655654 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/

Benchmarking www.ehowstuff.local (be patient)
Completed 100 requests
Completed 200 requests
Completed 300 requests
Completed 400 requests
Completed 500 requests
Completed 600 requests
Completed 700 requests
Completed 800 requests
Completed 900 requests
Completed 1000 requests
Finished 1000 requests


Server Software:        Apache/2.2.15
Server Hostname:        www.ehowstuff.local
Server Port:            8080

Document Path:          /
Document Length:        0 bytes

Concurrency Level:      50
Time taken for tests:   217.545 seconds
Complete requests:      1000
Failed requests:        81
   (Connect: 0, Receive: 0, Length: 81, Exceptions: 0)
Write errors:           0
Non-2xx responses:      1000
Keep-Alive requests:    0
Total transferred:      318518 bytes
HTML transferred:       20331 bytes
Requests per second:    4.60 [#/sec] (mean)
Time per request:       10877.237 [ms] (mean)
Time per request:       217.545 [ms] (mean, across all concurrent requests)
Transfer rate:          1.43 [Kbytes/sec] received

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0    3  12.1      0      65
Processing:   219 10822 17202.8   3275   61139
Waiting:      218 10802 17210.6   3228   61138
Total:        239 10825 17201.5   3275   61139

Percentage of the requests served within a certain time (ms)
  50%   3275
  66%   4513
  75%   5570
  80%  12099
  90%  40539
  95%  60069
  98%  60103
  99%  60200
 100%  61139 (longest request)

10. ApacheBench performance test with Varnish Cache

[root@centos6 ~]# ab -k -n 1000 -c 50 http://www.ehowstuff.local/
This is ApacheBench, Version 2.3 < $Revision: 655654 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/

Benchmarking www.ehowstuff.local (be patient)
Completed 100 requests
Completed 200 requests
Completed 300 requests
Completed 400 requests
Completed 500 requests
Completed 600 requests
Completed 700 requests
Completed 800 requests
Completed 900 requests
Completed 1000 requests
Finished 1000 requests


Server Software:        Apache/2.2.15
Server Hostname:        www.ehowstuff.local
Server Port:            80

Document Path:          /
Document Length:        7990 bytes

Concurrency Level:      50
Time taken for tests:   0.227 seconds
Complete requests:      1000
Failed requests:        0
Write errors:           0
Keep-Alive requests:    1000
Total transferred:      8565396 bytes
HTML transferred:       8221710 bytes
Requests per second:    4410.08 [#/sec] (mean)
Time per request:       11.338 [ms] (mean)
Time per request:       0.227 [ms] (mean, across all concurrent requests)
Transfer rate:          36888.79 [Kbytes/sec] received

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0    1   3.2      0      19
Processing:     7   10   1.7     10      18
Waiting:        1    4   2.3      4      15
Total:          7   11   4.1     10      31

Percentage of the requests served within a certain time (ms)
  50%     10
  66%     10
  75%     11
  80%     11
  90%     12
  95%     13
  98%     27
  99%     31
 100%     31 (longest request)

11. Result on Steps (9) and (10) shows that Apache with Varnish serve faster response than running Apache standalone.