apache/hadoop · error · IOException

Could not start Curator keyCacheListener for keys

Error message

Could not start Curator keyCacheListener for keys

What it means

Error "Could not start Curator keyCacheListener for keys" thrown in apache/hadoop.

Source

Thrown at hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/security/token/delegation/ZKDelegationTokenSecretManager.java:309

      keyCache = CuratorCache.bridgeBuilder(zkClient, ZK_DTSM_MASTER_KEY_ROOT)
          .build();
      CuratorCacheListener keyCacheListener = CuratorCacheListener.builder()
          .forCreatesAndChanges((oldNode, node) -> {
            try {
              processKeyAddOrUpdate(node.getData());
            } catch (IOException e) {
              LOG.error("Error while processing Curator keyCacheListener "
                  + "NODE_CREATED / NODE_CHANGED event");
              throw new UncheckedIOException(e);
            }
          })
          .forDeletes(childData -> processKeyRemoved(childData.getPath()))
          .build();
      keyCache.listenable().addListener(keyCacheListener);
      keyCache.start();
      loadFromZKCache(false);
    } catch (Exception e) {
      throw new IOException("Could not start Curator keyCacheListener for keys",
          e);
    }
    if (isTokenWatcherEnabled) {
      LOG.info("TokenCache is enabled");
      try {
        tokenCache = CuratorCache.bridgeBuilder(zkClient, ZK_DTSM_TOKENS_ROOT)
            .build();
        CuratorCacheListener tokenCacheListener = CuratorCacheListener.builder()
            .forCreatesAndChanges((oldNode, node) -> {
              try {
                processTokenAddOrUpdate(node.getData());
              } catch (IOException e) {
                LOG.error("Error while processing Curator tokenCacheListener "
                    + "NODE_CREATED / NODE_CHANGED event");
                throw new UncheckedIOException(e);
              }
            })
            .forDeletes(childData -> {

View on GitHub (pinned to 2add963021)

Solutions

1. The Curator cache listener for delegation keys failed to start. Check ZK connectivity and that the keys znode path exists; restart the service.

When it happens

Trigger: Thrown at hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/security/token/delegation/ZKDelegationTokenSecretManager.java:309 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/4c55a90ffd21a052. Report an issue: GitHub.