apache/hadoop · error · RuntimeException

Bad policy is found in EC policy configuration file

Error message

Bad policy is found in EC policy configuration file

What it means

Final validation in ECPolicyLoader.loadPolicy(Element, Map): a policy is accepted only if the referenced schema was resolved (schema != null, i.e. the <schema> text matches an id defined in <schemas>) AND the parsed cellSize is > 0. Anything else — unknown schema id, missing <cellsize> (defaults to 0), or cellsize <= 0 — throws this RuntimeException without naming the policy.

Source

Thrown at hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/util/ECPolicyLoader.java:323

              } catch (NumberFormatException e) {
                throw new IllegalArgumentException("Bad EC policy cellsize"
                    + " value " + value + " is found. It should be an integer");
              }
            } else {
              LOG.warn("Invalid tagName: " + tagName);
            }
          }
        } else {
          throw new IllegalArgumentException("Value of <" + tagName
              + "> is null");
        }
      }
    }

    if (schema != null && cellSize > 0) {
      return new ErasureCodingPolicy(schema, cellSize);
    } else {
      throw new RuntimeException("Bad policy is found in"
          + " EC policy configuration file");
    }
  }
}

View on GitHub (pinned to 2add963021)

Solutions

1. Check every <policy><schema> value against the ids in <schemas> and fix typos or renames
2. Add or correct the cell size: <cellsize>1048576</cellsize> (must be a positive integer)
3. Since the message does not name the policy, bisect: load with a single policy first, then add the rest back one by one

Example fix

<!-- before -->
<schemas>
  <schema id="rs-6-3">...</schema>
</schemas>
<policies>
  <policy>
    <name>RS-6-3</name>
    <schema>rs-63</schema>  <!-- typo: no such id -->
    <cellsize>1048576</cellsize>
  </policy>
</policies>

<!-- after -->
<schema>rs-6-3</schema>

Set<String> schemaIds = idsOf(doc, "schema");
for (Element p : policyElements(doc)) {
  String ref = textOf(p, "schema");
  if (!schemaIds.contains(ref)) throw new IllegalArgumentException("policy references unknown schema id " + ref);
  if (Integer.parseInt(textOf(p, "cellsize")) <= 0) throw new IllegalArgumentException("policy cellsize must be > 0");
}

try { new ECPolicyLoader().loadPolicy(path); }
catch (RuntimeException e) {
  LOG.error("EC policy file {} rejected: {}", path, e.getMessage()); // bisect policies if unclear
}

When it happens

Trigger: `hdfs ec -loadPolicy` where a policy references a schema id that is not defined in the <schemas> block (e.g. 'rs-3-2' with no matching <schema id="rs-3-2">), or the policy has no <cellsize> element at all so cellSize stays 0.

Common situations: Renaming a schema id but not the policies referencing it; deleting a schema while leaving its policies; authoring a policy with only <name> and <schema> because the template's cellsize line was lost.

Understand the failure class

Background: Config validation failed: what "invalid value for {key}" and settings-rejection errors mean across 19 open-source libraries — this error's family across 19 libraries.

Related errors

• Bad EC policy configuration file: top-level element not <con
• Bad EC policy configuration file: no <policies> element
• Bad EC policy configuration file: no <schemas> element
• Bad element in EC policy configuration file: {tagName}
• Value of <{tagName}> is null

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/b9f61a81ca680a31. Report an issue: GitHub.