Hello Poorvank, Thanks for driving this, I can understand how dynamically enabling FlameGraphs can be powerful, so +1 on the general idea.
1. Instead of adding a FlameGraph specific REST API did you consider adding a more general config API? Similar to that of the dynamical job configuration [1] endpoint but for cluster configs instead of job? We could add an allow list of supported config options and start with Flamegraph. This would allow other configs to use the API in the future without adding more APIs. 2. nit: As for the UI, I would prefer for the settings to take up less space. The new options are at the top of the view, even when not expanded. Thanks, Danny [1] https://cwiki.apache.org/confluence/display/FLINK/FLIP-530%3A+Dynamic+job+configuration On Tue, Aug 12, 2025 at 4:31 AM Poorvank Bhatia <puravbhat...@gmail.com> wrote: > Hi all, > > I would like to open a discussion proposing the ability to enable > flamegraphs at runtime and make their configuration i.e number of samples, > delay between samples, and stack depth *dynamically adjustable via the Web > UI*, without requiring any job or cluster restarts. > > As of now, enabling flamegraphs requires setting > *rest.flamegraph.enabled=true* and restarting the Job. This is not ideal > for debugging live issues, especially in production environments. > > I discussed this idea offline with Roman Khachatryan (author of FLIP-530 > < > https://cwiki.apache.org/confluence/display/FLINK/FLIP-530%3A+Dynamic+job+configuration > >), > Rui Fan, and Arvid Heise. While Rui noted that this could potentially align > with FLIP-530’s direction, Roman confirmed that it’s better handled as a > separate effort, since FLIP-530 > < > https://cwiki.apache.org/confluence/display/FLINK/FLIP-530%3A+Dynamic+job+configuration > > > is scoped to job-level config, whereas this proposal addresses > cluster-level observability via RestOptions. > > For Design Details, Please refer: Dynamic Flamegraph via UI > < > https://docs.google.com/document/d/1A9fLFgXMGxQQn6X8WCv7mLL21AnLqrDFvLSHnUg8rLA/edit?tab=t.0#heading=h.s351fc464ma6 > > > > I’ve attached a short demo to help visualize the proposed feature and > gather feedback. Demo > < > https://drive.google.com/file/d/1iik6aOc2uc9sFlHFlT8YDX5TKFdoD15u/view?usp=sharing > > > > Looking forward to your thoughts. > > Regards, > > Poorvank Bhatia >
