apache/hadoop · error · HadoopIllegalArgumentException

"System erasure coding policy " + name + " cannot be removed

Error message

"System erasure coding policy " + name + " cannot be removed"

What it means

Error ""System erasure coding policy " + name + " cannot be removed"" thrown in apache/hadoop.

Source

Thrown at hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/ErasureCodingPolicyManager.java:379

  private byte getNextAvailablePolicyID() {
    byte nextPolicyID = (byte)(getCurrentMaxPolicyID() + 1);
    return nextPolicyID > ErasureCodeConstants.USER_DEFINED_POLICY_START_ID ?
        nextPolicyID : ErasureCodeConstants.USER_DEFINED_POLICY_START_ID;
  }

  /**
   * Remove an User erasure coding policy by policyName.
   */
  public synchronized void removePolicy(String name) {
    final ErasureCodingPolicyInfo info = policiesByName.get(name);
    if (info == null) {
      throw new HadoopIllegalArgumentException("The policy name " +
          name + " does not exist");
    }

    final ErasureCodingPolicy ecPolicy = info.getPolicy();
    if (ecPolicy.isSystemPolicy()) {
      throw new HadoopIllegalArgumentException("System erasure coding policy " +
          name + " cannot be removed");
    }

    if (enabledPoliciesByName.containsKey(name)) {
      enabledPoliciesByName.remove(name);
      enabledPolicies =
          enabledPoliciesByName.values().toArray(new ErasureCodingPolicy[0]);
    }
    info.setState(ErasureCodingPolicyState.REMOVED);
    LOG.info("Remove erasure coding policy " + name);
    allPersistedPolicies.put(ecPolicy.getId(),
        createPolicyInfo(ecPolicy, ErasureCodingPolicyState.REMOVED));
    /*
     * TODO HDFS-12405 postpone the delete removed policy to Namenode restart
     * time.
     * */
  }

View on GitHub (pinned to 2add963021)

Solutions

1. Do not attempt to remove built-in system EC policies; only user-added policies can be removed.
2. If the goal is to disallow use, disable the policy instead of removing it.

When it happens

Trigger: Attempting to remove one of the built-in system erasure coding policies (e.g. RS-6-3-1024k), which may only be disabled, not removed.

Common situations: See trigger scenarios.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/a6c098b892b1104b. Report an issue: GitHub.