apache/hadoop · error · InvalidRequestException

Unknown pool poolName

Error message

Unknown pool poolName

What it means

Error "Unknown pool poolName" thrown in apache/hadoop.

Source

Thrown at hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/CacheManager.java:537

      throw new InvalidRequestException("Invalid negative ID.");
    }
    // Find the directive.
    CacheDirective directive = directivesById.get(id);
    if (directive == null) {
      throw new InvalidRequestException("No directive with ID " + id
          + " found.");
    }
    return directive;
  }

  /**
   * Get a CachePool by name, validating that it exists.
   */
  private CachePool getCachePool(String poolName)
      throws InvalidRequestException {
    CachePool pool = cachePools.get(poolName);
    if (pool == null) {
      throw new InvalidRequestException("Unknown pool " + poolName);
    }
    return pool;
  }

  // RPC handlers

  private void addInternal(CacheDirective directive, CachePool pool) {
    boolean addedDirective = pool.getDirectiveList().add(directive);
    assert addedDirective;
    directivesById.put(directive.getId(), directive);
    String path = directive.getPath();
    directivesByPath.put(path, directive);
    // Fix up pool stats
    CacheDirectiveStats stats =
        computeNeeded(directive.getPath(), directive.getReplication());
    directive.addBytesNeeded(stats.getBytesNeeded());
    directive.addFilesNeeded(directive.getFilesNeeded());

View on GitHub (pinned to 2add963021)

Solutions

1. Create the cache pool first with hdfs cacheadmin -addPool, or correct the pool name.
2. List pools with hdfs cacheadmin -listPools to verify the name.

When it happens

Trigger: modifyCacheDirective referencing a cache pool name that does not exist.

Common situations: See trigger scenarios.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/41cf0292135d4346. Report an issue: GitHub.