apache/hadoop · error · UnsupportedOperationException

Replica of type {} does not support getOriginalReplica

Error message

Replica of type {} does not support getOriginalReplica

What it means

ReplicaWaitingToBeRecovered (state RWR) deliberately does not support the recovery-info API surface: getOriginalReplica() throws UnsupportedOperationException because an RWR replica is not a wrapper around some other replica. Recovery metadata only exists on ReplicaUnderRecovery. This is a programming error, not an environmental condition.

Source

Thrown at hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/ReplicaWaitingToBeRecovered.java:101

  @Override  // Object
  public boolean equals(Object o) {
    return super.equals(o);
  }
  
  @Override  // Object
  public int hashCode() {
    return super.hashCode();
  }

  @Override
  public String toString() {
    return super.toString();
  }

  @Override
  public ReplicaInfo getOriginalReplica() {
    throw new UnsupportedOperationException("Replica of type " + getState() +
        " does not support getOriginalReplica");
  }

  @Override
  public long getRecoveryID() {
    throw new UnsupportedOperationException("Replica of type " + getState() +
        " does not support getRecoveryID");
  }

  @Override
  public void setRecoveryID(long recoveryId) {
    throw new UnsupportedOperationException("Replica of type " + getState() +
        " does not support getRecoveryID");
  }

  @Override
  public ReplicaRecoveryInfo createInfo() {
    throw new UnsupportedOperationException("Replica of type " + getState() +

View on GitHub (pinned to 2add963021)

Solutions

Guard with instanceof ReplicaUnderRecovery before calling getOriginalReplica()
Or gate on state: only ReplicaState.RUR exposes recovery info; skip FINALIZED/RBW/RWR/TEMPORARY
Re-check your recovery flow: RWR replicas become recoverable via ReplicaUnderRecovery wrapping, not directly

Example fix

// before
ReplicaInfo original = r.getOriginalReplica(); // throws for RWR

// after
ReplicaInfo original = (r instanceof ReplicaUnderRecovery)
    ? ((ReplicaUnderRecovery) r).getOriginalReplica()
    : r;

Defensive patterns

Strategy: type-guard

Validate before calling

if (!(r instanceof ReplicaUnderRecovery)) { /* RWR and others: use r itself */ }

Type guard

static boolean hasOriginalReplica(ReplicaInfo r) {
  return r instanceof ReplicaUnderRecovery;
}
// ReplicaInfo original = hasOriginalReplica(r) ? ((ReplicaUnderRecovery) r).getOriginalReplica() : r;

Try / catch

try { r.getOriginalReplica(); } catch (UnsupportedOperationException e) { /* not under recovery: fall back to treating r as the original */ }

Prevention

Never call recovery-info APIs without an instanceof ReplicaUnderRecovery check
Remember the state model: RUR wraps an original; RWR/RBW/FINALIZED/TEMPORARY do not

When it happens

Trigger: Calling getOriginalReplica() on any ReplicaInfo whose runtime type is ReplicaWaitingToBeRecovered - e.g., generic recovery code that assumes every non-finalized replica is under recovery and calls getOriginalReplica() without an instanceof check.

Common situations: Custom FsDataset implementations or tests that iterate the volume map during recovery and call the recovery API uniformly on all replicas; misclassifying RWR (replica waiting to be recovered because its datanode was down) as RUR (replica under recovery).

Related errors

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/590cfcc557b360e6. Report an issue: GitHub.