Buoyant’s battle to position Linkerd as the service mesh of choice received a $10 million funding boost that could come in handy as the Google-based Istio service mesh platform continues to gain momentum. And to add some drama into the mix, Google is tangentially linked to the new funding round.
The funding was led by GV, formerly known as Google Ventures and the investment arm of Google’s parent company Alphabet. Existing investors Benchmark and A. Capital also participated in the round. Buoyant has now raised $24 million through four funding rounds.
William Morgan, CEO of Buoyant and one of Linkerd’s creators, noted in an email that it will use the new investment to “further increase the pace of feature iteration in Linkerd.” He added that despite the connection between GV and Istio, the company would not “accept anything that gave Google any kind of influence over Linkerd.”
What is Linkerd?
Linkerd is an open source network proxy designed to be deployed as a service mesh. A service mesh is a dedicated layer for managing, controlling, and monitoring service-to-service communication within an application.
The platform was developed in 2015 and was adopted as a hosted project within the Cloud Native Computing Foundation (CNCF) in 2017. Buoyant remains the main source of code commits to Linkerd. A recent report from Mirantis’ Stackalytics showed that Buoyant was the source for 84 percent of code commits to the Linkerd service mesh project.
The Linderd community last September completely re-wrote the platform’s base in a move to bring it closer to the Kubernetes ecosystem. That move resulted in Linkerd 2.0, which Morgan at that time said made it “orders of magnitude smaller and faster” compared to its previous iteration.
Linkerd is also progressing toward eventual “graduation” status within CNCF. Morgan had said last year that such a move would happen “sooner rather than later,” though it looks like it will be the latter.
“I expect Linkerd meets the criteria already, but we’ve been prioritizing solving the needs of our users and adopters over going through the formal graduation process,” Morgan said. “We may take another look later this year.”
Linkerd Versus Istio
Linkerd is most often compared to the Istio service mesh that was launched in mid-2017, with the backing of Google, Lyft, and IBM. It was established to provide developers with visibility into microservices without the need to change application code. The platform sits at the network level and uses a substrate for microservices development and maintenance. This allows for the decoupling of management from application development.
The platform hit its 1.0 release in the middle of last year, which signified its readiness for general deployments. However, some noted that even with the 1.0 release, Istio was not quite ready for prime-time.
“I would say it was premature,” noted Christian Posta, senior principal architect at Red Hat, on the 1.0 release. “On the other hand, until you hit 1.0 people don’t give something a lot of attention. Even through it could have benefited from a few more months of work, at some point you have to ship it.”
Morgan said that he has witnessed a similar disconnect.
“Much of Linkerd’s recent momentum is from folks coming to Linkerd after struggling with Istio,” Morgan explained.
The Linkerd community has added support to the 1.x version of the platform that allows users to run both Linkerd and Istio. This involves using Istio as a control plane across Linkerd instances. However, Morgan was quick to point out that those efforts have been limited.
“While we did some initial experiments about using Linkerd with Istio several years ago, feedback from our adopters was very clear that they did not want anything to do with Istio,” Morgan noted. “Since then it has become clear to us that Istio’s approach is fundamentally bad for users.”
Istio has also yet to be officially adopted by cloud giants Amazon Web Services (AWS) and Microsoft Azure. And it remains outside of the CNCF framework.
Despite those challenges, Istio is still gaining converts. VMware late last year rolled out a beta program for its NSX Service Mesh based on Istio. This allows the vendor to extend its NSX networking and security capabilities across Kubernetes clusters via the Container Network Interface (CNI). And Google is, obviously, fully onboard.
Istio has also been bolstered by its link to the Envoy service proxy. Envoy was originally created by Lyft in 2015. It was developed as a service mesh substrate that provides common utilities such as service discovery, load balancing, rate limiting, circuit breaking, stats, logging, and tracing to heterogeneous application architectures. Basically, Envoy acts as the data plane, while Istio is the control plane.
Envoy is also part of the CNCF ecosystem, and last November was the third project to gain “graduation” status.
Morgan said the Linkerd community did not build on Envoy due to security concerns. Instead, Linkerd is built using the Rust programming language.
“We wanted the security benefits of Rust, and because we believed that building a specialized proxy specifically for the service mesh case would allow us to make something significantly faster and smaller than a general-purpose proxy like Envoy,” Morgan explained.