Sizing a Varnish platform: Live streaming

There's a recurring discussion I get myself into, and it goes roughly like this:

- I want to stream live video, what kind of machine, and how many of them do I need?
- It depends.
- Depends on what?
- Math! Also, numbers!
- ...
- Joking, can you tell me <list of characteristics>
- <provides value>
- <performs black magic>. The answer to your question is <scarily accurate values>!

Obviously, it doesn't go "exactly" like this, but the goal of this post is going to be largely about boring math, so it sounds cooler if we say I'll be talking about black magic, right?

Let's open the grimoires and see how we can answer this sizing question!

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7/19/17 1:30 PM
by Guillaume Quintard

Creating a self-routing Varnish cluster

In this post, I will explain how to create a highly available, self-routing sharded Varnish Cache cluster. This is similar to a standard sharded cluster with one exception, there is no dedicated routing tier. Each node in the cluster can route the request to the proper destination node, by itself.

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2/14/17 11:30 AM
by Reza Naghibi

Built for speed, Varnish Plus never slows down: Introducing the latest version


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11/15/16 2:00 PM
by Annette De Freitas

Backends: Well done, with a side of load balancing (part 2)

This blog post is part two of a two-part series. (Find part one here.)

Hello there! Welcome to the second part of this article in which we'll discuss a bit about directors and how to use them as well as an introduction to load balancing. The first part was about backends and probes, so if you don't know about them already, it's probably a good start to read it first. Go ahead, I'll wait.

Ready? Good!

Let's look back at our VCL from the previous post:

backend alpha { .host = ""; }
backend bravo { .host = ""; }

sub vcl_recv {
    if ( == "") {
        set req.backend_hint = alpha;
    } else if ( == "") {
        set req.backend_hint = bravo;
    } else {
        return (synth(404, "Host not found"));
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8/1/16 2:30 PM
by Guillaume Quintard

Varnish Software Blog

The Varnish blog is where our team writes about all things related to Varnish Cache and Varnish Software...or simply vents.



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