apache/hadoop · error · IllegalArgumentException

Target address cannot be null. (configuration property '${co

Error message

Target address cannot be null. (configuration property '${configName}')

What it means

IllegalArgumentException('Target address cannot be null.') from NetUtils.createSocketAddr when the target string is null. When the caller supplies a configName (e.g., 'fs.defaultFS', 'yarn.resourcemanager.scheduler.address'), the message appends '(configuration property ...)' pointing at the property whose value was null. This almost always means the configuration property was never set (or its containing *-site.xml was not loaded), not that null was passed deliberately.

Source

Thrown at hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/net/NetUtils.java:236

   * @param useCacheIfPresent Whether use cache when create URI
   * @return  socket addr
   */
  public static InetSocketAddress createSocketAddr(String target,
                                                   int defaultPort,
                                                   String configName,
                                                   boolean useCacheIfPresent) {
    return createSocketAddr(target, defaultPort, configName, useCacheIfPresent, true);
  }

  public static InetSocketAddress createSocketAddr(
      String target, int defaultPort, String configName,
      boolean useCacheIfPresent, boolean isResolved) {
    String helpText = "";
    if (configName != null) {
      helpText = " (configuration property '" + configName + "')";
    }
    if (target == null) {
      throw new IllegalArgumentException("Target address cannot be null." +
          helpText);
    }
    target = target.trim();
    boolean hasScheme = target.contains("://");
    URI uri = createURI(target, hasScheme, helpText, useCacheIfPresent);

    String host = uri.getHost();
    int port = uri.getPort();
    if (port == -1) {
      port = defaultPort;
    }
    String path = uri.getPath();

    if ((host == null) || (port < 0) ||
        (!hasScheme && path != null && !path.isEmpty())) {
      throw new IllegalArgumentException(
          "Does not contain a valid host:port authority: " + target + helpText
      );

View on GitHub (pinned to 2add963021)

Solutions

Set the named property in the correct *-site.xml and confirm it is actually loaded (e.g., 'hadoop fs -conf' dump or conf.get in a probe)
Use the current property key for your Hadoop version (fs.defaultFS since 2.x)
Guard the call: if (target == null) fail with a clear 'property X is not set' error before calling createSocketAddr

Example fix

// before
InetSocketAddress addr = NetUtils.createSocketAddr(conf.get("fs.defaultFS"), 8020, "fs.defaultFS");
// fs.defaultFS unset -> IllegalArgumentException

// after
String target = conf.get("fs.defaultFS");
if (target == null) throw new IllegalStateException("fs.defaultFS is not set in core-site.xml");
InetSocketAddress addr = NetUtils.createSocketAddr(target, 8020, "fs.defaultFS");

Defensive patterns

Strategy: validation

Validate before calling

String target = conf.get(configName);
if (target == null || target.trim().isEmpty()) {
  throw new IllegalStateException(configName + " is not set (or its site xml is not on the classpath)");
}

Try / catch

catch (IllegalArgumentException e) { /* 'Target address cannot be null. (configuration property ...)' */ the message names the property: set it and retry; }

Prevention

Assert required address properties are non-null during service initialization
Use version-correct property keys (fs.defaultFS on 2.x+)
Add config sanity checks in unit tests for every *-site.xml you ship

When it happens

Trigger: createSocketAddr(conf.get("fs.default.name"), 8020, "fs.default.name") when the property is absent; code deriving an address from HA nameservice resolution that returned null; a service address property empty in the loaded configuration.

Common situations: Wrong or missing *-site.xml on the classpath so conf.get returns null; property renamed between Hadoop versions (fs.default.name vs fs.defaultFS) so the old key is unset; test or tooling code forgetting to set an address before use.

Related errors

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/46d83369918cdc82. Report an issue: GitHub.