What causes "No addresses in endpoint" in apache/hadoop?

When publishing, always add at least one address (RegistryTypeUtils.uri(...) / hostnamePortPair(...)) before registering the record — Endpoint.validate also rejects empty lists

apache/hadoop · error · InvalidRecordException

No addresses in endpoint

Error message

No addresses in endpoint

What it means

retrieveAddressesUriType requires the endpoint's address list to contain at least one entry after passing the addressType check; an empty addresses list throws InvalidRecordException ('No addresses in endpoint'). The endpoint is typed correctly but was serialized with an empty or cleared address array.

Source

Thrown at hadoop-common-project/hadoop-registry/src/main/java/org/apache/hadoop/registry/client/binding/RegistryTypeUtils.java:195

  }

  /**
   * Get a single URI endpoint
   * @param epr endpoint
   * @return the uri of the first entry in the address list. Null if the endpoint
   * itself is null
   * @throws InvalidRecordException if the type is wrong, there are no addresses
   * or the payload ill-formatted
   */
  public static List<String> retrieveAddressesUriType(Endpoint epr)
      throws InvalidRecordException {
    if (epr == null) {
      return null;
    }
    requireAddressType(ADDRESS_URI, epr);
    List<Map<String, String>> addresses = epr.addresses;
    if (addresses.size() < 1) {
      throw new InvalidRecordException(epr.toString(),
          "No addresses in endpoint");
    }
    List<String> results = new ArrayList<String>(addresses.size());
    for (Map<String, String> address : addresses) {
      results.add(getAddressField(address, ADDRESS_URI));
    }
    return results;
  }

  /**
   * Get a specific field from an address -raising an exception if
   * the field is not present
   * @param address address to query
   * @param field field to resolve
   * @return the resolved value. Guaranteed to be non-null.
   * @throws InvalidRecordException if the field did not resolve
   */
  public static String getAddressField(Map<String, String> address,

View on GitHub (pinned to 2add963021)

Solutions

When publishing, always add at least one address (RegistryTypeUtils.uri(...) / hostnamePortPair(...)) before registering the record — Endpoint.validate also rejects empty lists
When consuming, check epr.addresses != null && !epr.addresses.isEmpty() before calling the retriever and skip/log the endpoint
Fix the writer: re-register the service record with populated addresses

Example fix

// before
Endpoint ep = new Endpoint("webhdfs", "uri", "/webhdfs");
record.addExternal(ep); // addresses empty -> No addresses in endpoint on read

// after
Endpoint ep = new Endpoint("webhdfs", "uri", "/webhdfs");
ep.addAddress(RegistryTypeUtils.uri("hdfs://namenode:9820"));
record.addExternal(ep);

Defensive patterns

Strategy: validation

Validate before calling

static boolean hasAddresses(Endpoint epr) {
  return epr != null && epr.addresses != null && !epr.addresses.isEmpty();
}

if (hasAddresses(epr) && AddressTypes.ADDRESS_URI.equals(epr.addressType)) {
  List<String> uris = RegistryTypeUtils.retrieveAddressesUriType(epr);
}

Type guard

static boolean isRetrievableUriEndpoint(Endpoint epr) {
  return epr != null
      && AddressTypes.ADDRESS_URI.equals(epr.addressType)
      && epr.addresses != null && !epr.addresses.isEmpty();
}

Prevention

Never register an Endpoint without at least one address — Endpoint.validate rejects it too
Add addresses via RegistryTypeUtils.uri(...)/hostnamePortPair(...) before record registration
Treat an empty-address endpoint as bad publisher data: log and skip rather than fail the whole read

When it happens

Trigger: A ServiceRecord published with an Endpoint whose addresses list is empty — e.g. new Endpoint(api, "uri", ...) with no addresses added — or JSON deserialized from a record where the addresses array is empty.

Common situations: Registration code that creates the Endpoint before resolving the service address and never populates it; schema changes that stopped writing the addresses field; hand-built records in tests.

Related errors

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/12cbb3d8176f0cff. Report an issue: GitHub.