java.lang.IllegalStateException: Error while creating AdminClient for Cluster

[marteloudini]

Issue submitter TODO list

• I've looked up my issue in FAQ
• I've searched for an already existing issues here
• I've tried running main-labeled docker image and the issue still persists there
• I'm running a supported version of the application which is listed here

Describe the bug (actual behavior)

Hey,
i have the same issue, but with not SSL needed.
app.kubernetes.io/version: v1.4.2
helm.sh/chart: kafka-ui-1.6.0
im on windows 11; Podman Desktop; Kind.

I see the home page, but when i clic on Broker, Consumer, Topics i have white page ?? (cf logs error below)

i forward port for see on browser :

my configmap kafka-ui:

   kafka:
      clusters:
        - name: my-cluster
          bootstrapServers: my-cluster-kafka-bootstrap:9092
    auth:
      type: disabled
    management:
      health:
        ldap:
          enabled: false

I see the home page, but when i clic on Broker, Consumer, Topics i have white page ?? (cf logs error below)

i have one topic (my-topic)
i have one consumer terminal actif
i have one producer terminal actif
i have 2 messages test.

My Deployment yaml from helm :

apiVersion: apps/v1
kind: Deployment
metadata:
  name: kafbat-ui-kafka-ui
  namespace: kafbat-ui
  uid: de7adf11-a4e7-4248-9a6d-cb949d6191e4
  resourceVersion: '283328'
  generation: 1
  creationTimestamp: '2026-02-17T14:30:24Z'
  labels:
    app.kubernetes.io/instance: kafbat-ui
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/name: kafka-ui
    app.kubernetes.io/version: v1.4.2
    helm.sh/chart: kafka-ui-1.6.0
  annotations:
    deployment.kubernetes.io/revision: '1'
    meta.helm.sh/release-name: kafbat-ui
    meta.helm.sh/release-namespace: kafbat-ui
  selfLink: /apis/apps/v1/namespaces/kafbat-ui/deployments/kafbat-ui-kafka-ui
status:
  observedGeneration: 1
  replicas: 1
  updatedReplicas: 1
  readyReplicas: 1
  availableReplicas: 1
  terminatingReplicas: 0
  conditions:
    - type: Progressing
      status: 'True'
      lastUpdateTime: '2026-02-17T14:30:56Z'
      lastTransitionTime: '2026-02-17T14:30:24Z'
      reason: NewReplicaSetAvailable
      message: ReplicaSet "kafbat-ui-kafka-ui-7955757f8d" has successfully progressed.
    - type: Available
      status: 'True'
      lastUpdateTime: '2026-02-19T07:24:03Z'
      lastTransitionTime: '2026-02-19T07:24:03Z'
      reason: MinimumReplicasAvailable
      message: Deployment has minimum availability.
spec:
  replicas: 1
  selector:
    matchLabels:
      app.kubernetes.io/instance: kafbat-ui
      app.kubernetes.io/name: kafka-ui
  template:
    metadata:
      labels:
        app.kubernetes.io/instance: kafbat-ui
        app.kubernetes.io/name: kafka-ui
      annotations:
        checksum/config: e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855
        checksum/configFromValues: 01ba4719c80b6fe911b091a7c05124b64eeece964e09c058ef8f9805daca546b
        checksum/secret: 01ba4719c80b6fe911b091a7c05124b64eeece964e09c058ef8f9805daca546b
    spec:
      volumes:
        - name: kafka-ui-yaml-conf-configmap
          configMap:
            name: kafbat-ui-configmap
            defaultMode: 420
      containers:
        - name: kafka-ui
          image: ghcr.io/kafbat/kafka-ui:v1.4.2
          ports:
            - name: http
              containerPort: 8080
              protocol: TCP
          env:
            - name: SPRING_CONFIG_ADDITIONAL-LOCATION
              value: /kafka-ui/config.yml
          resources: {}
          volumeMounts:
            - name: kafka-ui-yaml-conf-configmap
              mountPath: /kafka-ui/
          livenessProbe:
            httpGet:
              path: /actuator/health
              port: http
              scheme: HTTP
            initialDelaySeconds: 10
            timeoutSeconds: 10
            periodSeconds: 30
            successThreshold: 1
            failureThreshold: 3
          readinessProbe:
            httpGet:
              path: /actuator/health
              port: http
              scheme: HTTP
            initialDelaySeconds: 10
            timeoutSeconds: 10
            periodSeconds: 30
            successThreshold: 1
            failureThreshold: 3
          terminationMessagePath: /dev/termination-log
          terminationMessagePolicy: File
          imagePullPolicy: IfNotPresent
          securityContext: {}
      restartPolicy: Always
      terminationGracePeriodSeconds: 30
      dnsPolicy: ClusterFirst
      serviceAccountName: kafbat-ui-kafka-ui
      serviceAccount: kafbat-ui-kafka-ui
      securityContext: {}
      schedulerName: default-scheduler
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxUnavailable: 25%
      maxSurge: 25%
  revisionHistoryLimit: 10
  progressDeadlineSeconds: 600

### my logs ERROR :

2026-02-19T08:07:30.278Z  WARN 1 --- [undedElastic-14] org.apache.kafka.clients.ClientUtils     : Couldn't resolve server my-cluster-kafka-bootstrap:9092 from bootstrap.servers as DNS resolution failed for my-cluster-kafka-bootstrap
2026-02-19T08:07:30.278Z ERROR 1 --- [   scheduling-1] o.s.s.s.TaskUtils$LoggingErrorHandler    : Unexpected error occurred in scheduled task

java.lang.IllegalStateException: Error while creating AdminClient for the cluster my-cluster
	at io.kafbat.ui.service.AdminClientServiceImpl.lambda$createAdminClient$5(AdminClientServiceImpl.java:62) ~[!/:v1.4.2]
	at reactor.core.publisher.Mono.lambda$onErrorMap$29(Mono.java:3862) ~[reactor-core-3.7.12.jar!/:3.7.12]
	at reactor.core.publisher.FluxOnErrorResume$ResumeSubscriber.onError(FluxOnErrorResume.java:94) ~[reactor-core-3.7.12.jar!/:3.7.12]
	at reactor.core.publisher.MonoFlatMap$FlatMapMain.onError(MonoFlatMap.java:180) ~[reactor-core-3.7.12.jar!/:3.7.12]
	at reactor.core.publisher.FluxSubscribeOnCallable$CallableSubscribeOnSubscription.run(FluxSubscribeOnCallable.java:231) ~[reactor-core-3.7.12.jar!/:3.7.12]
	at reactor.core.scheduler.SchedulerTask.call(SchedulerTask.java:68) ~[reactor-core-3.7.12.jar!/:3.7.12]
	at reactor.core.scheduler.SchedulerTask.call(SchedulerTask.java:28) ~[reactor-core-3.7.12.jar!/:3.7.12]
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:317) ~[na:na]
	at java.base/java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:304) ~[na:na]
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144) ~[na:na]
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642) ~[na:na]
	at java.base/java.lang.Thread.run(Thread.java:1583) ~[na:na]
	Suppressed: java.lang.Exception: #block terminated with an error
		at reactor.core.publisher.BlockingSingleSubscriber.blockingGet(BlockingSingleSubscriber.java:104) ~[reactor-core-3.7.12.jar!/:3.7.12]
		at reactor.core.publisher.Mono.block(Mono.java:1779) ~[reactor-core-3.7.12.jar!/:3.7.12]
		at io.kafbat.ui.service.ClustersStatisticsScheduler.updateStatistics(ClustersStatisticsScheduler.java:30) ~[!/:v1.4.2]
		at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[na:na]
		at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[na:na]
		at org.springframework.scheduling.support.ScheduledMethodRunnable.runInternal(ScheduledMethodRunnable.java:130) ~[spring-context-6.2.12.jar!/:6.2.12]
		at org.springframework.scheduling.support.ScheduledMethodRunnable.lambda$run$2(ScheduledMethodRunnable.java:124) ~[spring-context-6.2.12.jar!/:6.2.12]
		at io.micrometer.observation.Observation.observe(Observation.java:498) ~[micrometer-observation-1.15.5.jar!/:1.15.5]
		at org.springframework.scheduling.support.ScheduledMethodRunnable.run(ScheduledMethodRunnable.java:124) ~[spring-context-6.2.12.jar!/:6.2.12]
		at org.springframework.scheduling.config.Task$OutcomeTrackingRunnable.run(Task.java:87) ~[spring-context-6.2.12.jar!/:6.2.12]
		at org.springframework.scheduling.support.DelegatingErrorHandlingRunnable.run(DelegatingErrorHandlingRunnable.java:54) ~[spring-context-6.2.12.jar!/:6.2.12]
		at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:572) ~[na:na]
		at java.base/java.util.concurrent.FutureTask.runAndReset(FutureTask.java:358) ~[na:na]
		at java.base/java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:305) ~[na:na]
		... 3 common frames omitted
Caused by: org.apache.kafka.common.KafkaException: Failed to create new KafkaAdminClient
	at org.apache.kafka.clients.admin.KafkaAdminClient.createInternal(KafkaAdminClient.java:561) ~[kafka-clients-7.9.0-ccs.jar!/:na]
	at org.apache.kafka.clients.admin.KafkaAdminClient.createInternal(KafkaAdminClient.java:512) ~[kafka-clients-7.9.0-ccs.jar!/:na]
	at org.apache.kafka.clients.admin.Admin.create(Admin.java:137) ~[kafka-clients-7.9.0-ccs.jar!/:na]
	at org.apache.kafka.clients.admin.AdminClient.create(AdminClient.java:39) ~[kafka-clients-7.9.0-ccs.jar!/:na]
	at io.kafbat.ui.service.AdminClientServiceImpl.lambda$createAdminClient$2(AdminClientServiceImpl.java:56) ~[!/:v1.4.2]
	at reactor.core.publisher.MonoSupplier.call(MonoSupplier.java:67) ~[reactor-core-3.7.12.jar!/:3.7.12]
	at reactor.core.publisher.FluxSubscribeOnCallable$CallableSubscribeOnSubscription.run(FluxSubscribeOnCallable.java:228) ~[reactor-core-3.7.12.jar!/:3.7.12]
	... 7 common frames omitted
Caused by: org.apache.kafka.common.config.ConfigException: No resolvable bootstrap urls given in bootstrap.servers
	at org.apache.kafka.clients.ClientUtils.parseAndValidateAddresses(ClientUtils.java:104) ~[kafka-clients-7.9.0-ccs.jar!/:na]
	at org.apache.kafka.clients.ClientUtils.parseAndValidateAddresses(ClientUtils.java:63) ~[kafka-clients-7.9.0-ccs.jar!/:na]
	at org.apache.kafka.clients.admin.internals.AdminBootstrapAddresses.fromConfig(AdminBootstrapAddresses.java:72) ~[kafka-clients-7.9.0-ccs.jar!/:na]
	at org.apache.kafka.clients.admin.KafkaAdminClient.createInternal(KafkaAdminClient.java:530) ~[kafka-clients-7.9.0-ccs.jar!/:na]
	... 13 common frames omitted

2026-02-19T08:07:55.273Z DEBUG 1 --- [    parallel-16] i.k.u.s.ClustersStatisticsScheduler      : Start getting metrics for kafkaCluster: my-cluster
2026-02-19T08:07:55.274Z  INFO 1 --- [undedElastic-15] o.a.k.clients.admin.AdminClientConfig    : AdminClientConfig values:
	auto.include.jmx.reporter = true
	bootstrap.controllers = []
	bootstrap.servers = [my-cluster-kafka-bootstrap:9092]
	client.dns.lookup = use_all_dns_ips
	client.id = kafbat-ui-admin-1771488475-104
	connections.max.idle.ms = 300000
	default.api.timeout.ms = 60000
	enable.metrics.push = true
	metadata.max.age.ms = 300000
	metadata.recovery.strategy = none
	metric.reporters = []
	metrics.num.samples = 2
	metrics.recording.level = INFO
	metrics.sample.window.ms = 30000
	receive.buffer.bytes = 65536
	reconnect.backoff.max.ms = 1000
	reconnect.backoff.ms = 50
	request.timeout.ms = 30000
	retries = 2147483647
	retry.backoff.max.ms = 1000
	retry.backoff.ms = 100
	sasl.client.callback.handler.class = null
	sasl.jaas.config = null
	sasl.kerberos.kinit.cmd = /usr/bin/kinit
	sasl.kerberos.min.time.before.relogin = 60000
	sasl.kerberos.service.name = null
	sasl.kerberos.ticket.renew.jitter = 0.05
	sasl.kerberos.ticket.renew.window.factor = 0.8
	sasl.login.callback.handler.class = null
	sasl.login.class = null
	sasl.login.connect.timeout.ms = null
	sasl.login.read.timeout.ms = null
	sasl.login.refresh.buffer.seconds = 300
	sasl.login.refresh.min.period.seconds = 60
	sasl.login.refresh.window.factor = 0.8
	sasl.login.refresh.window.jitter = 0.05
	sasl.login.retry.backoff.max.ms = 10000
	sasl.login.retry.backoff.ms = 100
	sasl.mechanism = GSSAPI
	sasl.oauthbearer.clock.skew.seconds = 30
	sasl.oauthbearer.expected.audience = null
	sasl.oauthbearer.expected.issuer = null
	sasl.oauthbearer.header.urlencode = false
	sasl.oauthbearer.jwks.endpoint.refresh.ms = 3600000
	sasl.oauthbearer.jwks.endpoint.retry.backoff.max.ms = 10000
	sasl.oauthbearer.jwks.endpoint.retry.backoff.ms = 100
	sasl.oauthbearer.jwks.endpoint.url = null
	sasl.oauthbearer.scope.claim.name = scope
	sasl.oauthbearer.sub.claim.name = sub
	sasl.oauthbearer.token.endpoint.url = null
	security.protocol = PLAINTEXT
	security.providers = null
	send.buffer.bytes = 131072
	socket.connection.setup.timeout.max.ms = 30000
	socket.connection.setup.timeout.ms = 10000
	ssl.cipher.suites = null
	ssl.enabled.protocols = [TLSv1.2, TLSv1.3]
	ssl.endpoint.identification.algorithm = https
	ssl.engine.factory.class = null
	ssl.key.password = null
	ssl.keymanager.algorithm = SunX509
	ssl.keystore.certificate.chain = null
	ssl.keystore.key = null
	ssl.keystore.location = null
	ssl.keystore.password = null
	ssl.keystore.type = JKS
	ssl.protocol = TLSv1.3
	ssl.provider = null
	ssl.secure.random.implementation = null
	ssl.trustmanager.algorithm = PKIX
	ssl.truststore.certificates = null
	ssl.truststore.location = null
	ssl.truststore.password = null
	ssl.truststore.type = JKS

Expected behavior

No response

Your installation details

app.kubernetes.io/version: v1.4.2
helm.sh/chart: kafka-ui-1.6.0

Steps to reproduce

&

Screenshots

No response

Logs

No response

Additional context

No response

[github-actions]

Hi marteloudini! 👋

Welcome, and thank you for opening your first issue in the repo!

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[RotemCDos]

Hi :)
It doesn't look like an issue related to the UI in my opinion.
There is an error in the first line of your attached log: Couldn't resolve server my-cluster-kafka-bootstrap:9092 from bootstrap.servers as DNS resolution failed for my-cluster-kafka-bootstrap.
It appears that the UI loaded fine but couldn't resolve your bootstrap servers. Is the Kafka cluster itself on the same namespace as the kafka-ui? If not, you might have to use the Fully Qualified Domain Name (FQDN) of your Kafka service, for example: my-cluster-kafka-bootstrap.your-kafka-namespace.svc.cluster.local:9092.
If you are able to connect to your Kafka cluster from within the kafka-ui namespace using the bootstrap servers you provided - make sure that the kafka-ui pod successfully loaded all of your configurations.

Anyways, I am not a part of the Kafbat kafka-ui team so maybe one of them will be able to give a more detailed answer.