apache/hadoop · error · IllegalArgumentException

Invalid entry, invalid destination nameservice {}

Error message

Invalid entry, invalid destination nameservice {}

What it means

Error "Invalid entry, invalid destination nameservice {}" thrown in apache/hadoop.

Source

Thrown at hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/store/records/MountTable.java:397

  @Override
  public void validate() {
    super.validate();
    if (this.getSourcePath() == null || this.getSourcePath().length() == 0) {
      throw new IllegalArgumentException(
          ERROR_MSG_NO_SOURCE_PATH + this);
    }
    if (!this.getSourcePath().startsWith("/")) {
      throw new IllegalArgumentException(
          ERROR_MSG_MUST_START_WITH_BACK_SLASH + this);
    }
    if (this.getDestinations() == null || this.getDestinations().size() == 0) {
      throw new IllegalArgumentException(
          ERROR_MSG_NO_DEST_PATH_SPECIFIED + this);
    }
    for (RemoteLocation loc : getDestinations()) {
      String nsId = loc.getNameserviceId();
      if (nsId == null || nsId.length() == 0) {
        throw new IllegalArgumentException(
            ERROR_MSG_INVALID_DEST_NS + this);
      }
      if (loc.getDest() == null || loc.getDest().length() == 0) {
        throw new IllegalArgumentException(
            ERROR_MSG_INVALID_DEST_PATH + this);
      }
      if (!loc.getDest().startsWith("/")) {
        throw new IllegalArgumentException(
            ERROR_MSG_ALL_DEST_MUST_START_WITH_BACK_SLASH + this);
      }
    }
    if (isFaultTolerant()) {
      if (getDestinations().size() < 2) {
        throw new IllegalArgumentException(
            ERROR_MSG_FAULT_TOLERANT_MULTI_DEST + this);
      }
      if (!isAll()) {
        throw new IllegalArgumentException(

View on GitHub (pinned to 2add963021)

Solutions

1. Use a configured, valid nameservice id for the destination (check dfs.nameservices / router nameservice config).
2. Fix typos in the nameservice id passed to the mount add command.

When it happens

Trigger: MountTable validation: a destination entry has a null/empty or invalid nameservice id.

Common situations: Mount entry referencing a nameservice that does not exist in the federation configuration.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/445721f8dc3709b8. Report an issue: GitHub.