Announcing Linkerd 2.6: Distributed tracing, live request headers, faster dashboard, and more!

William Morgan

William Morgan
October 10, 2019 • 4 min read

A picture of some chairs

Today we’re happy to announce the release of Linkerd 2.6! This release adds support for distributed tracing, brings request and response headers to Linkerd’s live tap output, adds traffic split visualizations to the dashboard, dramatically improves the performance of the dashboard on large clusters, adds a public Helm repo, and much, much more.

Linkerd’s new distributed tracing support means that Linkerd’s data plane proxy now emit trace spans, allowing proxy timing for individual requests to be captured with systems like Jaeger. Since distributed tracing is a complex topic that (unlike most of Linkerd’s features!) requires some investment to use, Linkerd maintainer Alex Leong has written a handy blog post describing how to assemble a functioning end-to-end distributed tracing system with Linkerd 2.6.

This release also adds live request and response headers to Linkerd’s tap output. Linkerd’s tap feature provides a live sample of actual requests flowing between any two pods, deployments, or namespaces. (Particularly useful since Linkerd encrypts all meshed HTTP traffic by default!) In Linkerd 2.5, we ensured that tap obeyed Kubernetes RBAC restrictions; the addition of 2.6 headers brings us one step closer to our vision of a complete “tcpdump for microservices”–if tcpdump obeyed fine-grained access control, that is.

Linkerd 2.6 brings several improvements to Linkerd’s dashboard. First, we’ve dramatically reduced the Prometheus load generated by the dashboard—the dashboard should now be usable on large clusters, and cause significantly less load even on small ones. Second, the dashboard now includes a visualization of the traffic split feature for canary deployments, which is already causing some excitement in the community:

Finally, following up on our Helm work from the previous release, we’re happy to announce that Linkerd now has a public Helm repo! We’ve published a guide to installing Linkerd with Helm from this public repo.

Linkerd 2.6 additionally brings a tremendous list of other improvements, performance enhancements, and bug fixes, including:

  • A new --cluster-domain flag to linkerd install for clusters that have a customized domain instead of “cluster.local”.
  • A new namespace-level Grafana dashboard.
  • A new JSON output option to linkerd tap.
  • A new node selector constraint to Helm installation, allowing mixed-cluster installation.
  • And lots, lots more. See the full release notes for details.

If you’ve been watching the clock, this release hits at just around 7 weeks since Linkerd 2.5. This high velocity release cycle is only possible thanks to the rapidly-growing Linkerd community of contributors, testers, and adopters. A special thanks to Alena Varkockova, Armin Bürkle, Bruno M. Custódio, Pascal Bourque, Brian Storti, Kevin Taylor, Eugene Glotov, pierDipi, and Tarun Pothulapati.

📣 We want to meet you! Next month many of the Linkerd maintainers and contributors will be converging on Kubecon NA in San Diego. Alex Leong will be hosting a Linkerd in Production Workshop, and William and Oliver will be delivering introductory and deep-dive talks, respectively. That’s not to mention the Linkerd talks by engineers from Nordstorm, Microsoft, Paybase, OpenFaaS, Buoyant, and many more. If you’re attending, please swing by the #kccnc19 channel in the Linkerd Slack, and find us in the Linkerd booth in person!

Ready to try Linkerd? Those of you who have been tracking the 2.x branch via our weekly edge releases will already have seen these features in action. Either way, you can download the stable 2.6 release by running:

curl https://run.linkerd.io/install | sh

Upgrading from a previous release? See our handy Linkerd upgrade guide for how to use the linkerd upgrade command.

Linkerd is a community project and is hosted by the Cloud Native Computing Foundation. If you have feature requests, questions, or comments, we’d love to have you join our rapidly-growing community! Linkerd is hosted on GitHub, and we have a thriving community on Slack, Twitter, and the mailing lists. Come and join the fun!

(Image credit: neonow)

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