As discussed from the very beginning, back in Chapter 1,
microservices applications are utterly reliant on the network for all of their
communications. Networks are slower and less reliable than in-process
communication, which introduces new failure modes and presents new challenges
to our applications.
For service mesh users, where the mesh mediates all your application traffic,
the reliability benefit is that the mesh can make intelligent choices about
what to do when things go wrong. In this chapter, we’ll talk about the
mechanisms that Linkerd provides to mitigate the problems of unreliability in
the network, helping to address the inherent instability of microservices
applications.
Load Balancing
Load balancing might seem like an odd reliability feature to lead with, since
many people think that Kubernetes already handles it. As we first discussed in
Chapter 5, Kubernetes Services make a distinction
between the IP address of the Service and the IP addresses of the Pods
associated with the Service. When traffic is sent to the ClusterIP, it ends up
being redirected to one of the endpoint IPs.
However, in Kubernetes, the built-in load balancing is limited to entire
connections. Linkerd improves on this by using the proxy, which understands
more about the protocol involved in the connection, to choose an endpoint for
each request, as shown in Figure 11-1.
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month, and much more.
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.
Julian F.
Head of Cybersecurity
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.
Addison B.
Field Engineer
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.
Amir M.
Data Platform Tech Lead
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.
