apache/hadoop · error · IllegalArgumentException

Invalid entry, fault tolerance requires multiple destination

Error message

Invalid entry, fault tolerance requires multiple destinations {}

What it means

Error "Invalid entry, fault tolerance requires multiple destinations {}" 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:411

    }
    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;
  }

  @Override
  public int hashCode() {
    return new HashCodeBuilder(17, 31)
        .append(this.getSourcePath())

View on GitHub (pinned to 2add963021)

Solutions

1. Add at least two destination nameservices when enabling fault tolerance on the mount entry.
2. Or remove the fault-tolerance flag if a single destination is intended.

When it happens

Trigger: MountTable validation: fault-tolerant mode requested but fewer than two destinations configured.

Common situations: Admin enabled fault tolerance on a mount with only one destination.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/449be21e33937929. Report an issue: GitHub.