Modifying the Proxy Log Level

Emitting logs is an expensive operation for a network proxy, and by default, the Linkerd data plane proxies are configured to only log exceptional events. However, sometimes it is useful to increase the verbosity of proxy logs to assist with diagnosing proxy behavior. Happily, Linkerd allows you to modify these logs dynamically.

The log level of a Linkerd proxy can be modified on the fly by using the proxy’s /proxy-log-level endpoint.

For example, to change the proxy log level of the web-c4d87867-h7sdx pod to debug, run:

kubectl port-forward -n emojivoto web-c4d87867-h7sdx 4191
curl -v --data 'linkerd=debug' -X PUT localhost:4191/proxy-log-level

The resulting logs can be viewed with kubectl logs.

If changes to the proxy log level should be retained beyond the lifetime of a pod, add the config.linkerd.io/proxy-log-level annotation to the pod template.

The syntax of the proxy log level can be found in the proxy log level reference.

Note that logging has a noticeable, negative impact on proxy throughput. If the pod will continue to serve production traffic, you may wish to reset the log level once you are done.