apache/hadoop · error · IllegalArgumentException

Invalid entry, all destination must start with / {}

Error message

Invalid entry, all destination must start with / {}

What it means

Error "Invalid entry, all destination must start with / {}" 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:405

      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(
            ERROR_MSG_FAULT_TOLERANT_ALL + this);
      }
    }
  }

  @Override
  public long getExpirationMs() {
    return 0;

View on GitHub (pinned to 2add963021)

Solutions

1. Make every destination path absolute (start with '/').
2. Fix the entry with dfsrouteradmin -update or remove and re-add it with correct paths.

When it happens

Trigger: MountTable validation: a destination path does not start with '/'.

Common situations: Relative destination paths supplied when adding or updating a mount entry.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/e7d7ce13349a8fd9. Report an issue: GitHub.