Jenkins agent errors upgrading to Java 21

Hi, I am using Jenkins 2.462.3 container image on OpenShift and I am trying to upgrade from Java 11 to Java 21. I keep getting this error on JNLP client side:

Dec 16, 2024 10:09:02 AM com.splunk.splunkjenkins.console.ConsoleRecordCacheUtils flushLog
SEVERE: flush log error
java.lang.IllegalStateException: Jenkins.instance is missing. Read the documentation of Jenkins.getInstanceOrNull to see what you are doing wrong.
	at Jenkins v2.462.3//jenkins.model.Jenkins.get(Jenkins.java:824)
	at Jenkins v2.462.3//jenkins.model.GlobalConfiguration.all(GlobalConfiguration.java:75)
	at Jenkins v2.462.3//jenkins.model.JenkinsLocationConfiguration.get(JenkinsLocationConfiguration.java:65)
	at PluginClassLoader for splunk-devops//com.splunk.splunkjenkins.SplunkJenkinsInstallation.getMetadataHost(SplunkJenkinsInstallation.java:598)
	at PluginClassLoader for splunk-devops//com.splunk.splunkjenkins.model.EventRecord.getMetaData(EventRecord.java:138)
	at PluginClassLoader for splunk-devops//com.splunk.splunkjenkins.model.EventRecord.toMap(EventRecord.java:160)
	at PluginClassLoader for splunk-devops//com.splunk.splunkjenkins.utils.LogEventHelper.toJson(LogEventHelper.java:837)
	at PluginClassLoader for splunk-devops//com.splunk.splunkjenkins.utils.SplunkLogService.sendBatch(SplunkLogService.java:175)
	at PluginClassLoader for splunk-devops-extend//com.splunk.splunkjenkins.console.ConsoleRecordCacheUtils.flushLog(ConsoleRecordCacheUtils.java:43)
	at PluginClassLoader for splunk-devops-extend//com.splunk.splunkjenkins.console.ConsoleRecordCacheUtils.enqueue(ConsoleRecordCacheUtils.java:32)
	at PluginClassLoader for splunk-devops-extend//com.splunk.splunkjenkins.console.LabelConsoleLineStream.eol(LabelConsoleLineStream.java:58)
	at PluginClassLoader for splunk-devops-extend//com.splunk.splunkjenkins.console.LabelConsoleLineStream.write(LabelConsoleLineStream.java:36)
	at java.base/java.io.FilterOutputStream.write(FilterOutputStream.java:139)
	at PluginClassLoader for credentials-binding//org.jenkinsci.plugins.credentialsbinding.masking.SecretPatterns$MaskingOutputStream.eol(SecretPatterns.java:111)
	at Jenkins v2.462.3//hudson.console.LineTransformationOutputStream.eol(LineTransformationOutputStream.java:69)
	at Jenkins v2.462.3//hudson.console.LineTransformationOutputStream.write(LineTransformationOutputStream.java:62)
	at Jenkins v2.462.3//hudson.console.LineTransformationOutputStream.write(LineTransformationOutputStream.java:84)
	at java.base/java.io.PrintStream.implWrite(PrintStream.java:643)
	at java.base/java.io.PrintStream.write(PrintStream.java:623)
	at java.base/sun.nio.cs.StreamEncoder.writeBytes(StreamEncoder.java:309)
	at java.base/sun.nio.cs.StreamEncoder.implFlushBuffer(StreamEncoder.java:405)
	at java.base/sun.nio.cs.StreamEncoder.lockedFlushBuffer(StreamEncoder.java:123)
	at java.base/sun.nio.cs.StreamEncoder.flushBuffer(StreamEncoder.java:110)
	at java.base/java.io.OutputStreamWriter.flushBuffer(OutputStreamWriter.java:192)
	at java.base/java.io.PrintStream.implWriteln(PrintStream.java:849)
	at java.base/java.io.PrintStream.writeln(PrintStream.java:826)
	at java.base/java.io.PrintStream.println(PrintStream.java:1168)
	at PluginClassLoader for git-client//org.jenkinsci.plugins.gitclient.CliGitAPIImpl.launchCommandIn(CliGitAPIImpl.java:2805)
	at PluginClassLoader for git-client//org.jenkinsci.plugins.gitclient.CliGitAPIImpl$9.execute(CliGitAPIImpl.java:3174)
	at PluginClassLoader for git-client//org.jenkinsci.plugins.gitclient.RemoteGitImpl$CommandInvocationHandler$GitCommandMasterToSlaveCallable.call(RemoteGitImpl.java:170)
	at PluginClassLoader for git-client//org.jenkinsci.plugins.gitclient.RemoteGitImpl$CommandInvocationHandler$GitCommandMasterToSlaveCallable.call(RemoteGitImpl.java:161)
	at hudson.remoting.UserRequest.perform(UserRequest.java:211)
	at hudson.remoting.UserRequest.perform(UserRequest.java:54)
	at hudson.remoting.Request$2.run(Request.java:377)
	at hudson.remoting.InterceptingExecutorService.lambda$wrap$0(InterceptingExecutorService.java:78)
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:317)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642)
	at hudson.remoting.Engine$1.lambda$newThread$0(Engine.java:140)
	at java.base/java.lang.Thread.run(Thread.java:1583)

Environment:

Jenkins setup:Jenkins: 2.462.3
OS: Linux - 5.14.0-284.55.1.el9_2.x86_64
Java: 21.0.5 - Red Hat, Inc. (OpenJDK 64-Bit Server VM)
---
ace-editor:1.1
ansicolor:1.0.4
ant:497.v94e7d9fffa_b_9
antisamy-markup-formatter:162.v0e6ec0fcfcf6
apache-httpcomponents-client-4-api:4.5.14-208.v438351942757
asm-api:9.7.1-97.v4cc844130d97
authentication-tokens:1.53.v1c90fd9191a_b_
authorize-project:1.7.2
blueocean:1.27.9
blueocean-autofavorite:1.2.5
blueocean-bitbucket-pipeline:1.27.9
blueocean-commons:1.27.9
blueocean-config:1.27.9
blueocean-core-js:1.27.9
blueocean-dashboard:1.27.9
blueocean-display-url:2.4.2
blueocean-events:1.27.9
blueocean-git-pipeline:1.27.9
blueocean-github-pipeline:1.27.9
blueocean-i18n:1.27.9
blueocean-jwt:1.27.9
blueocean-personalization:1.27.9
blueocean-pipeline-api-impl:1.27.9
blueocean-pipeline-editor:1.27.9
blueocean-pipeline-scm-api:1.27.9
blueocean-rest:1.27.9
blueocean-rest-impl:1.27.9
blueocean-web:1.27.9
bootstrap5-api:5.3.2-4
bouncycastle-api:2.30.1.78.1-248.ve27176eb_46cb_
branch-api:2.1144.v1425d1c3d5a_7
build-blocker-plugin:166.vc82fc20b_a_ed6
cachet-gating:1.0.10
caffeine-api:3.1.8-133.v17b_1ff2e0599
checks-api:2.0.2
cloudbees-bitbucket-branch-source:866.vdea_7dcd3008e
cloudbees-folder:6.858.v898218f3609d
command-launcher:107.v773860566e2e
commons-lang3-api:3.14.0-76.vda_5591261cfe
commons-text-api:1.12.0-119.v73ef73f2345d
conditional-buildstep:1.4.3
config-file-provider:959.vcff671a_4518b_
configuration-as-code:1836.vccda_4a_122a_a_e
configuration-as-code-groovy:1.1
copyartifact:746.vd2a_674fb_4f6f
cpaas-jenkins-plugin:0.0.14
credentials:1384.vf0a_2ed06f9c6
credentials-binding:681.vf91669a_32e45
data-tables-api:1.13.8-2
display-url-api:2.204.vf6fddd8a_8b_e9
docker-commons:439.va_3cb_0a_6a_fb_29
durable-task:550.v0930093c4b_a_6
echarts-api:5.4.3-2
eddsa-api:0.3.0-4.v84c6f0f4969e
email-ext:2.104
favorite:2.208.v91d65b_7792a_c
font-awesome-api:6.5.1-3
git:5.2.1
git-client:5.0.0
git-server:99.101.v720e86326c09
github:1.37.3.1
github-api:1.318-461.v7a_c09c9fa_d63
github-branch-source:1772.va_69eda_d018d4
gitlab-plugin:1.8.1
google-oauth-plugin:1.330.vf5e86021cb_ec
groovy:457.v99900cb_85593
gson-api:2.11.0-41.v019fcf6125dc
handy-uri-templates-2-api:2.1.8-30.v7e777411b_148
htmlpublisher:1.33
instance-identity:185.v303dc7c645f9
ionicons-api:74.v93d5eb_813d5f
jackson2-api:2.17.0-379.v02de8ec9f64c
jakarta-activation-api:2.1.3-1
jakarta-mail-api:2.1.3-1
javadoc:243.vb_b_503b_b_45537
javax-activation-api:1.2.0-7
javax-mail-api:1.6.2-10
jaxb:2.3.9-1
jdk-tool:73.vddf737284550
jenkins-design-language:1.27.9
jersey2-api:2.42-147.va_28a_44603b_d5
jira:3.12
jjwt-api:0.11.5-77.v646c772fddb_0
jms-messaging:1.1.27
job-dsl:1.87
joda-time-api:2.12.7-29.v5a_b_e3a_82269a_
jquery3-api:3.7.1-1
jsch:0.2.16-86.v42e010d9484b_
json-api:20240303-41.v94e11e6de726
json-path-api:2.8.0-21.v8b_7dc8b_1037b_
junit:1296.vb_f538b_c88630
kubernetes:4174.v4230d0ccd951
kubernetes-client-api:6.9.2-239.ve49a_3f285167
kubernetes-credentials:173.v04e9c17cffd7
lockable-resources:1232.v512d6c434eb_d
mailer:472.vf7c289a_4b_420
mapdb-api:1.0.9-28.vf251ce40855d
matrix-auth:3.2.2
matrix-project:832.va_66e270d2946
maven-plugin:3.23
mercurial:1260.vdfb_723cdcc81
metrics:4.2.18-442.v02e107157925
mina-sshd-api-common:2.12.1-113.v4d3ea_5eb_7f72
mina-sshd-api-core:2.12.1-113.v4d3ea_5eb_7f72
momentjs:1.1.1
oauth-credentials:0.646.v02b_66dc03d2e
okhttp-api:4.11.0-157.v6852a_a_fa_ec11
openshift-client:1.1.0.424.v829cb_ccf8798
openshift-login:1.1.0.248.v1908df5c4f5e
openshift-sync:1.1.0.802.v45585f8cdc07
opentelemetry:3.1215.vc9db_a_0b_34c2a_
pam-auth:1.10
parameterized-scheduler:277.v61a_4b_a_49a_c5c
parameterized-trigger:787.v665fcf2a_830b_
pipeline-build-step:540.vb_e8849e1a_b_d8
pipeline-graph-analysis:202.va_d268e64deb_3
pipeline-groovy-lib:700.v0e341fa_57d53
pipeline-input-step:477.v339683a_8d55e
pipeline-milestone-step:111.v449306f708b_7
pipeline-model-api:2.2168.vf921b_4e72c73
pipeline-model-definition:2.2168.vf921b_4e72c73
pipeline-model-extensions:2.2168.vf921b_4e72c73
pipeline-rest-api:2.34
pipeline-stage-step:305.ve96d0205c1c6
pipeline-stage-tags-metadata:2.2168.vf921b_4e72c73
pipeline-stage-view:2.34
pipeline-utility-steps:2.16.0
plain-credentials:182.v468b_97b_9dcb_8
plugin-util-api:4.1.0
prism-api:1.29.0-15
prometheus:2.5.1
pubsub-light:1.18
rebuild:332.va_1ee476d8f6d
resource-disposer:0.23
run-condition:1.7
scm-api:689.v237b_6d3a_ef7f
script-security:1341.va_2819b_414686
slack:722.vd07f1ea_7ff40
snakeyaml-api:2.2-121.v5a_68b_9300b_d4
splunk-devops:1.10.2
splunk-devops-extend:1.10.2
sse-gateway:1.26
ssh-agent:367.vf9076cd4ee21
ssh-credentials:337.v395d2403ccd4
ssh-slaves:2.968.v6f8823c91de4
sshd:3.330.vc866a_8389b_58
structs:338.v848422169819
subversion:2.17.3
throttle-concurrents:2.14
timestamper:1.27
token-macro:400.v35420b_922dcb_
trilead-api:2.147.vb_73cc728a_32e
validating-string-parameter:183.v3748e79b_9737
variant:60.v7290fc0eb_b_cd
workflow-aggregator:596.v8c21c963d92d
workflow-api:1316.v33eb_726c50b_a_
workflow-basic-steps:1042.ve7b_140c4a_e0c
workflow-cps:3837.v305192405b_c0
workflow-cps-global-lib:609.vd95673f149b_b
workflow-durable-task-step:1378.v6a_3e903058a_3
workflow-job:1385.vb_58b_86ea_fff1
workflow-multibranch:773.vc4fe1378f1d5
workflow-scm-step:415.v434365564324
workflow-step-api:657.v03b_e8115821b_
workflow-support:865.v43e78cc44e0d
ws-cleanup:0.46

Please advise how can I possibly fix this

The actual issue was with the memory quota for the pod and not with Jenkins.