Varnish is a proxy and cache, or HTTP accelerator, designed to improve performance for busy, dynamic web sites. By redirecting traffic to static pages whenever possible, varnish reduces the number of dynamic page calls, thus reducing load.
Varnish is part of Extra Packages for Enterprise Linux (EPEL), which is a community repository of non-standard packages for the RHEL distribution. First, we’ll install the EPEL repository:
rpm -iUvh http://dl.fedoraproject.org/pub/epel/7/x86_64/e/epel-release-7-2.noarch.rpm
Step 2: Install Varnish
First, you’ll follow a simple best practice: ensuring the list of available packages is up to date before installing anything new.
yum -y update
At this point, installing Varnish is as simple as running just one command:
yum -y install varnish
Step 3: Start Varnish
To configure varnish to start at boot, run the following command:
systemctl enable varnish
To start varnish, run the following command as root:
systemctl start varnish
To check the status of varnish, run the following command as root:
systemctl status varnish
Check the version of Varnish that is running:
varnishd -V
Varnish is configured to listen on port 6081 by default. It expects your web server to be local, or on the same serve,r and listening on port 8080.
Step 4: Configuration File Locations
A basic and default configuration file can be found at:
/etc/varnish/default.vcl
An example configuration can be found in example.vcl:
/usr/share/doc/varnish-4.0.1/example.vcl
To view or edit example.vcl:
vim /usr/share/doc/varnish-4.0.1/example.vcl
