This was a tough nut to crack. I updated the LTS jenkins version I had running to 2.516.1 LTS and started jenkins. It started but was using JDK-17. As I had JDK-21 still installed, I stopped jenkins service, used update-alternatives --config java to set it to jdk-21. When I started the new jenkins LTS version with jdk-21, it worked. So, there must have been some incompatibility in 2.504.1 and jdk-21. Resolved! Thanks for all your comments and help. Kelly Holt - Omron SQA Manager
On Friday, August 1, 2025 at 11:26:00 AM UTC-6 Kelly Holt wrote: > I am using OpenJDK-17 > [openjdk version "17.0.15" 2025-04-15 > OpenJDK Runtime Environment (build 17.0.15+6-Ubuntu-0ubuntu124.04) > OpenJDK 64-Bit Server VM (build 17.0.15+6-Ubuntu-0ubuntu124.04, mixed > mode, sharing)] > dpkg -l shows: > ii openjdk-17-jdk:amd64 17.0.15+6~us1-0ubuntu1~24.04 > amd64 OpenJDK Development Kit (JDK) > ii openjdk-17-jdk-headless:amd64 17.0.15+6~us1-0ubuntu1~24.04 > amd64 OpenJDK Development Kit (JDK) (headless) > ii openjdk-17-jre:amd64 17.0.15+6~us1-0ubuntu1~24.04 > amd64 OpenJDK Java runtime, using Hotspot JIT > ii openjdk-17-jre-headless:amd64 17.0.15+6~us1-0ubuntu1~24.04 > amd64 OpenJDK Java runtime, using Hotspot JIT (headless) > > Jenkins Server Version is 2.504.1 > > I'll have to try to switch it again after working hours. The Jenkins > server is currently needed to run several builds. > > On Fri, Aug 1, 2025 at 9:23 AM Verachten Bruno <[email protected]> wrote: > >> Hello Kelly, >> >> Thank you for reaching out and sharing the details of your issue. >> Could you let us know which version of Jenkins you are trying to run with >> JDK 21? >> Any recent LTS version should generally work without any issues. If >> you're using a non-LTS version or an older release, that might explain the >> problem you're encountering. >> Additionally, it could be helpful to double-check the compatibility of >> any plugins you have installed, as certain plugins might not yet fully >> support JDK 21. If you haven't already, reviewing the Jenkins logs in >> detail might provide more clues, even if the initial error message seems >> vague. >> >> Best regards, >> Bruno Verachten >> >> On Fri, Aug 1, 2025 at 5:15 PM Kelly Holt <[email protected]> wrote: >> >>> I'm stumped here. I got the same warning message and have followed the >>> instructions found on the link [Java 21 upgrade instructions >>> <https://www.jenkins.io/doc/book/platform-information/upgrade-java-to-21/>], >>> but >>> when I go to start Jenkins, it fails. The logs are not much help other than >>> Jenkins failed to start. Using update-alternatives to set the JDK back to >>> Ubuntu's OpenJDK-17-jdk, then Jenkins server starts as expected. Am I >>> missing something here? Is there something wrong with my installation? I >>> also tried Openjdk-21-jdk from Ubuntu default installation and I get the >>> same issue: Jenkins fails to start. >>> >>> Any help is appreciated. >>> Kelly Holt >>> On Tuesday, April 29, 2025 at 4:39:34 PM UTC-6 Kevin Martens wrote: >>> >>>> Hi Maciej, >>>> >>>> Thanks for raising this issue. I wanted to share that I've gone through >>>> the jenkins.io documentation and believe I have created or updated all >>>> the documentation spots for Java 21. This includes Java 21 upgrade >>>> instructions >>>> <https://www.jenkins.io/doc/book/platform-information/upgrade-java-to-21/>, >>>> >>>> an update to the platform information page >>>> <https://www.jenkins.io/doc/book/platform-information/> to include >>>> Java 21, various installation documentation being updated to use images >>>> with Java 21 such as Linux >>>> <https://www.jenkins.io/doc/book/installing/linux/> and Docker >>>> <https://www.jenkins.io/doc/book/installing/docker/>, and any area >>>> that would have previously used Java 17. If there are any other areas of >>>> documentation that need to be updated accordingly, please let me know and >>>> I'd be happy to make sure that everything is current. >>>> >>>> Thanks very much, >>>> >>>> Kevin Martens, Jenkins Documentation Officer >>>> >>>> On Thursday, April 10, 2025 at 6:34:22 AM UTC-4 maciej wrote: >>>> >>>>> Ullrich Hafner (2025-04-09 21:05): >>>>> >>>>> Yes, you are right. It makes sense to switch to Java 21 in the next >>>>> couple of months (actually I never understood why one should not directly >>>>> move from Java 11 to Java 21 for the controllers, as we also fully >>>>> support >>>>> Java 21 from the beginning of the Java 17 switch). The plan is to switch >>>>> the weekly Jenkins releases to Java 21 in the middle of this year. >>>>> See >>>>> https://www.jenkins.io/blog/2023/11/06/introducing-2-2-2-java-support-plan/ >>>>> >>>>> If you find such wrong references of the Java version in out >>>>> documentation it would be helpful if you can either create an issue in >>>>> Jira >>>>> or even better: click the „Improve the page“ button and fix the >>>>> corresponding page by yourself. This helps us a lot as the documentation >>>>> is >>>>> spread along a lot of different files... >>>>> >>>>> >>>>> The link does explain a bit, thanks. It talks about dropping JDK11, >>>>> though. >>>>> >>>>> As for the docs updates, I really don't know what problems come with >>>>> the upgrade, so I can't write about that. Should I expect everything to >>>>> just work? Will all plugins work? Is there a tester script for this? Are >>>>> popular plugins tested with various versions of Java automatically? >>>>> >>>>> I saw the video on upgrading to JDK17 (linked in the docs >>>>> <https://www.jenkins.io/doc/book/platform-information/upgrade-java-to-17/index.html>), >>>>> >>>>> and it just talks about how to check my Java version and how to make sure >>>>> the main node and builder nodes use the same Java version (which is >>>>> helpful >>>>> but doesn't explain much). It does seem like a very manual process to >>>>> verify the upgrade. >>>>> >>>>> Cheers, >>>>> Maciej Nux >>>>> >>>> -- >>> You received this message because you are subscribed to the Google >>> Groups "Jenkins Users" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to [email protected]. >>> To view this discussion visit >>> https://groups.google.com/d/msgid/jenkinsci-users/c61cacaa-2b22-453f-a6c7-a43b78803cffn%40googlegroups.com >>> >>> <https://groups.google.com/d/msgid/jenkinsci-users/c61cacaa-2b22-453f-a6c7-a43b78803cffn%40googlegroups.com?utm_medium=email&utm_source=footer> >>> . >>> >> >> >> -- >> Bruno Verachten >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Jenkins Users" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> > To view this discussion visit >> https://groups.google.com/d/msgid/jenkinsci-users/CACtV%3DdfApyZzme8-tchj7Bc3mQUG8icWniF3j%3DKdifhrqR8WJw%40mail.gmail.com >> >> <https://groups.google.com/d/msgid/jenkinsci-users/CACtV%3DdfApyZzme8-tchj7Bc3mQUG8icWniF3j%3DKdifhrqR8WJw%40mail.gmail.com?utm_medium=email&utm_source=footer> >> . >> > -- You received this message because you are subscribed to the Google Groups "Jenkins Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/jenkinsci-users/2408f893-4871-46ae-bd6a-3b974411df99n%40googlegroups.com.
