Tuning Varnish startup parameters


thread_pools = (Number of CPU cores)
thread_pool_min = (800 / Number of CPU cores)
thread_pool_max = 4000
timeout_linger = 50
malloc,(yourmemory - 20%)G

Varnish Administration Certification Class – Milan, Italy


Partecipa al primo training italiano di ‪‎Varnish‬ Software in collaborazione con ‪FullTechnology‬ ed ottieni la certificazione!

Il corso si terrà a Milano il 2-3-4 Febbraio e prevede teoria, esercitazioni ed esame finalizzato al conseguimento della certificazione ed indirizzato a sysAdmin/devOps.

Partecipa all’evento di Milano

Varnish Administration Certification Class - Milan, Italy
Varnish Administration Certification Class – Milan, Italy

Varnish High Availability (VHA) 1.2 released


Varnish Software just released a new version of Varnish High Avalability (VHA) 1.2 that boosts the following features plus some bug fixes in order to bring cache setups to be more efficiente and resilient:

ESI support: if you use dynamic content with Varnish, you are probably familiar with ESI. It allows you to include various objects inside a page on the server-side, letting Varnish build content using cached objects. VHA is now able to replicate this content, including all the multiple sub-requests caused by it, giving you replication without losing granularity in your content.

Better job scheduling: With v1.1 we gained support for multiple neighbors, but it was still a bit wild west-y, and in some circumstances, a slow neighbor could slow the replication for the other, well-behaved servers. This limitation has been fixed, letting the fast guys be fast no matter what.

Better autoscaling integration: VHA used to be very picky about its configuration file. Now it’s smarter and allows you to run/reload without neighbors for example. This permits an easier management of elastic clusters, a very popular setup. While not exactly part of VHA, I’d like to point out that we now have a ready-made solution to reconfigure automatically your VHA setup in a elastic cluster context. So if a neighbor is taken down or pops up, we’ll now and act on it.

Strict mode: Tight discipline also has its merits, and in a fixed setup, you may want to keep the old, picky behaviour as an effective error detection mechanism. Well, you can! You only need to activate an option, and you’re set.

Optional node name: VHA is able to use the hostname of the machine as it node name, making the ‘-m’ switch optional, and above all, adding genericity to the configuration.

In order to update just do the following:

 # Update and verify that installed vha-agent is version 1.2.1
yum update -y varnish-plus-ha 

This should be the correct results:

Varnish High Availability Agent 1.2
Varnish High Availability Agent 1.2

HTTPie: a CLI, cURL-like tool for humans


HTTPie is available on Linux, Mac OS X and Windows. On a Debian or Ubuntu system HTTPie can be installed with apt-get install httpie. For other platforms, see http://httpie.org.

Testing httpie is simple:

http -p Hh http://www.atomictag.com
GET / HTTP/1.1
Accept: */*
Accept-Encoding: gzip, deflate
Connection: keep-alive
Host: www.atomictag.com
User-Agent: HTTPie/0.9.2
HTTP/1.1 200 OK
CF-RAY: 250beb7295742666-FRA
Cache-Control: max-age=0, public
Content-Encoding: gzip
Content-Type: text/html; charset=UTF-8
Date: Sun, 06 Dec 2015 23:55:06 GMT
ETag: W/"7524-526422bb3df6c"
Expires: Sun, 06 Dec 2015 23:55:06 GMT
Last-Modified: Sun, 06 Dec 2015 22:22:06 GMT
Pragma: public
Server: cloudflare-nginx
Set-Cookie: __cfduid=dad70ed346cbd17091806e91a67d56c1f1449446106; expires=Mon, 05-Dec-16 23:55:06 GMT; path=/; domain=.atomictag.com; HttpOnly
Transfer-Encoding: chunked
Vary: Accept-Encoding,Cookie

The -p option to http can be used to control output. Specifically:

-p H will print request headers.
-p h will print response headers.
-p B will print request body.
-p b will print response body.


Caching requests by HTTP status code


Sometimes you may want to cache request based on the status code with a different TTL.

Adding the following in the vcl_backend_response will help you in achieving the result:

if (beresp.status == 403 || beresp.status == 404 || beresp.status >= 500)
   set beresp.ttl = 60s;

Partner Event in Milan: all things Varnish and how Conde Nast uses Varnish Plus


The Varnish Software and Fulltechnology Partner Conference on 17th September in Milan, Italy is fast approaching! Here are some highlights we want to share with you.

You will have the opportunity to meet both Lars Larsson, CEO of Varnish Software, and Francesco Meani, CEO of Fulltechnology at the conference.

We are also excited to announce that the leading global mass media giant Conde Nast will speak at the event and share their user experience with Varnish Plus. Conde Nast Italy’s CTO, Giuseppe Serrecchia, will present real-life examples of how Conde Nast has developed and used Varnish Plus to meet their specific needs and what the outcomes were. Read more about in our blog post.

If you’re curious about the more technical aspects of Varnish Plus in action including tips and tricks for using Varnish Plus as an advanced load balancer and administration console (Varnish Administration Console), this event is your chance to learn. Fulltechnology, a leading interactive and technology player that designs, builds and executes software platforms, will augment the real-world Varnish Plus information with its own commercial and technical insights.

The program includes:

  • Tips & tricks for using Varnish as an advanced load-balancer and VAC
  • The benefits of Varnish Plus and its latest addition SSL/TLS
  • Commercial and technical insights from Fulltechnology
  • Condé Nast business case study and their user experience with Varnish
  • After event drinks and networking

Space is limited, so sign up now to participate at this conference.

Add to my calendar

To receive updates about the event and information about guest speakers, you can follow our blog here.

We are looking forward to meeting you in Milan!

SSL in Varnish Cache Plus


Varnish Software announced that they finished implementing SSL in Varnish Cache Plus.

The release will happen at at Varnish summit in Silicon Valley in early June.

Varnish Cache Plus is both a HTTP server and a HTTP client and both implementations will have SSL enabled. The HTTP Server, ie the client facing SSL is perhaps the most significant one, enabling Varnish Cache Plus to encrypt traffic between the client and Varnish.

Read more at: SSL in Varnish Cache Plus