Hi Martijn, We run a mix of Java 17/21 with the latest Flink 2.3 (there are some jobs in 1.20 that we will migrate soon).
I have seen lately many "Java shops" wanted to be up to speed with Java 25, however the majority is still somewhere between Java 11 or 17. My observation is that all the recent adopters (within the last year) - especially those running on kube start Java 17+. I think it's really important for Flink moving forward to be able to support faster, newer Java versions. Hope this helps and thanks for driving this. Best, Giannis On Fri, 30 Oct 2026 at 8:35 PM, Daniel Burrell via user < [email protected]> wrote: > Hi Martijn, > > Thanks for driving this FLIP. > > While the rest of our platform has already migrated to Java 25, our Flink > workloads remain pinned to Java 21 due to open Flink JIRAs. We build and > run on Java 21 and deploy onto Kubernetes. > > Operating a monorepo means this version mismatch creates serious overhead > - our shared internal libraries cannot adopt Java 25, and our build system > requires custom workarounds just to accommodate Flink. We ran into this > same delay with previous Java upgrades (21 and I think 17). > > Being held back by Flink’s release cadence has become painful enough that > we are currently evaluating alternative technologies. > > We strongly advocate for Flink prioritizing faster adoption of newer Java > releases. > > Kind regards > > Dan Burrell > > > > > On Fri, 30 Oct 2026 at 18:24, Martijn Visser <[email protected]> > wrote: > >> Hi everyone, >> >> I’m planning to write a FLIP about which Java versions Flink should >> support going forward. Before I do, I’d like to understand how you actually >> run Flink today. >> >> Could you reply with as much of the following as you're comfortable >> sharing? >> >> 1. Which Flink version(s) do you run in production? >> 2. Which Java version runs your Flink cluster (JobManager/TaskManager)? >> 3. Which Java version do you use to compile your jobs, and which language >> level do you target? >> 4. How do you deploy Flink: official Docker images, your own images, a >> managed/vendor service, or something else? >> 5. Do you plan to move to a newer Java version in the next 12 months? If >> not, what's stopping you (dependencies, platform constraints, company >> policy, ...)? >> 6. Are there features in newer Java releases you'd like Flink to use or >> support? >> >> Partial answers help too. A single line like "Flink 1.20, Java 11, own >> Docker images, no upgrade planned because of X" is already valuable. >> >> I’ll use your responses to make sure the proposal reflects how Flink >> users run Java today and where you’re heading. Nothing has been decided >> yet: the FLIP itself will be discussed on the dev list, and any change to >> the supported versions will be announced well in advance. >> >> Thanks in advance! >> >> Best regards, >> >> Martijn >> > > *This email and any files transmitted with it are confidential and > intended solely for the use of the individual or entity to whom they are > addressed. If you are not the named addressee you must not disseminate, > distribute or copy this e-mail. Please notify us on [email protected] > <[email protected]> immediately if you have received this e-mail by > mistake and delete this e-mail from your system. If you are not the > intended recipient you are notified that disclosing, copying, distributing > or taking any action in reliance on the contents of this information is > strictly prohibited.*
