provectus/kafka-ui · warning · TopicAnalysisException

Topic is already analyzing

Error message

Topic is already analyzing

What it means

TopicAnalysisService.startAnalysis is synchronized per service and refuses to start a second analysis for the same cluster/topic while one is already registered in the analysisTasksStore, throwing TopicAnalysisException('Topic is already analyzing').

Solutions

1. Wait for the current analysis to finish before starting a new one
2. Check analysis status via the stats/analysis endpoint instead of re-triggering
3. Restart the application or cancel/stop the running analysis task if it is stuck
4. Deduplicate requests client-side (disable button while analysis in progress)

Example fix

// before
analyzeTopic(cluster, topic); // may throw if running
analyzeTopic(cluster, topic); // second call throws
// after
if (!getAnalysisStatus(cluster, topic).isInProgress()) {
  analyzeTopic(cluster, topic);
}

// Java (caller)
TopicAnalysisStatusDTO st = topicAnalysisService.analyzeStatus(cluster, topicName); // via API endpoint
boolean inProgress = st.getStatus() == AnalysisStatusDTO.PENDING || st.getStatus() == AnalysisStatusDTO.RUNNING;
if (!inProgress) topicAnalysisService.analyze(cluster, topicName);

try {
  topicAnalysisService.analyze(cluster, topicName);
} catch (TopicAnalysisException e) {
  if ("Topic is already analyzing".equals(e.getMessage())) {
    log.info("Analysis already running for {}:{} — skipping", cluster, topicName);
  } else { throw e; }
}

When it happens

Trigger: Calling the analyze endpoint (TopicAnalysisService.analyze) twice for the same topic before the first run completes, or while a previous task is still queued/running in the scheduler.

Common situations: Double-clicking the 'Analyze' button; parallel CI jobs analyzing the same topic; a previous analysis stuck (large topic) and user retries; multiple browser tabs.

Understand the failure class

Background: "Invalid state transition" errors: "status must be X, actually Y", "already rejected/charging/uninstalled", "cannot ... while running" — what they mean when a library rejects your call — this error's family across 31 libraries.

Related errors

• Application config isn't valid. Cluster names should be…
• Application config isn't valid. Two clusters can't have the…
• seekTo should be set if seekType is
• Schema Registry is not set for cluster
• ANY operation can be only part of filter

AI-assisted analysis of provectus/kafka-ui@83b5a60cc0 (2026-09-08). Data as JSON: /api/errors/2d1da3f5081c33b1. Report an issue: GitHub.

Appendix: source

Thrown at kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/analyze/TopicAnalysisService.java:57

      10, //ttl for idle threads (in sec)
      true //daemon
  );

  private final AnalysisTasksStore analysisTasksStore = new AnalysisTasksStore();

  private final TopicsService topicsService;
  private final ConsumerGroupService consumerGroupService;

  public Mono<Void> analyze(KafkaCluster cluster, String topicName) {
    return topicsService.getTopicDetails(cluster, topicName)
        .doOnNext(topic -> startAnalysis(cluster, topicName))
        .then();
  }

  private synchronized void startAnalysis(KafkaCluster cluster, String topic) {
    var topicId = new TopicIdentity(cluster, topic);
    if (analysisTasksStore.isAnalysisInProgress(topicId)) {
      throw new TopicAnalysisException("Topic is already analyzing");
    }
    var task = new AnalysisTask(cluster, topicId);
    analysisTasksStore.registerNewTask(topicId, task);
    SCHEDULER.schedule(task);
  }

  public void cancelAnalysis(KafkaCluster cluster, String topicName) {
    analysisTasksStore.cancelAnalysis(new TopicIdentity(cluster, topicName));
  }

  public Optional<TopicAnalysisDTO> getTopicAnalysis(KafkaCluster cluster, String topicName) {
    return analysisTasksStore.getTopicAnalysis(new TopicIdentity(cluster, topicName));
  }

  class AnalysisTask implements Runnable, Closeable {

    private final Instant startedAt = Instant.now();

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