apache/iceberg · warning

Failed to create lock {}

Error message

Failed to create lock {}

What it means

MetastoreLock.createLock requests a lock from the Hive Metastore via client.lock(request). On TException (thrift transport/protocol error), it logs this warning with the LockRequest, then attempts to locate the lock via findLock(); if the lock cannot be found the exception is rethrown (on Hive >= 2).

Source

Thrown at hive-metastore/src/main/java/org/apache/iceberg/hive/MetastoreLock.java:309

    AtomicBoolean interrupted = new AtomicBoolean(false);
    Tasks.foreach(lockRequest)
        .retry(Integer.MAX_VALUE - 100)
        .exponentialBackoff(
            lockCreationMinWaitTime, lockCreationMaxWaitTime, lockCreationTimeout, 2.0)
        .shouldRetryTest(
            e ->
                !interrupted.get()
                    && e instanceof LockException
                    && HiveVersion.min(HiveVersion.HIVE_2))
        .throwFailureWhenFinished()
        .run(
            request -> {
              try {
                LockResponse lockResponse = metaClients.run(client -> client.lock(request));
                lockInfo.lockId = lockResponse.getLockid();
                lockInfo.lockState = lockResponse.getState();
              } catch (TException te) {
                LOG.warn("Failed to create lock {}", request, te);
                try {
                  // If we can not check for lock, or we do not find it, then rethrow the exception
                  // Otherwise we are happy as the findLock sets the lockId and the state correctly
                  if (HiveVersion.min(HiveVersion.HIVE_2)) {
                    LockInfo lockFound = findLock();
                    if (lockFound != null) {
                      lockInfo.lockId = lockFound.lockId;
                      lockInfo.lockState = lockFound.lockState;
                      LOG.info("Found lock {} by agentInfo {}", lockInfo, agentInfo);
                      return;
                    }
                  }

                  throw new LockException(
                      "Failed to find lock for table %s.%s", databaseName, tableName);
                } catch (InterruptedException e) {
                  Thread.currentThread().interrupt();
                  interrupted.set(true);

View on GitHub (pinned to 86d9c8fc54)

Solutions

1. Check HMS connectivity and health (metastore logs, network, port)
2. Retry the operation — the code already retries via findLock; transient TExceptions often resolve
3. Verify Hive version compatibility of the metastore client vs server (HiveVersion.min(HIVE_2) path)
4. Increase metastore client timeouts / connection pool settings if under load

Example fix

// before
ops.commit(); // transient TException creating lock
// after
Tasks.foreach(() -> ops.commit())
    .retry(3)
    .exponentialBackoff(100, 1000)
    .throwFailureWhenFinished();

// Check HMS reachability before commit-heavy workflows
try (HiveMetaStoreClient c = new HiveMetaStoreClient(hiveConf)) { c.getAllDatabases(); }

try { ops.commit(); } catch (org.apache.iceberg.exceptions.CommitFailedException e) { /* re-acquire lock / retry commit */ }

When it happens

Trigger: Acquiring a Hive lock for a commit when the metastore call fails — HMS unreachable, thrift session expired/invalid, metastore rejecting the lock request.

Common situations: HMS restarted between checkLock and lock acquisition; network blips to metastore; Hive 1.x where findLock behavior differs; concurrent lock contention triggering metastore errors.

Understand the failure class

Background: 'Something went wrong' / 'Request failed (500)' / 'HTTP error! status: 404' — what failed HTTP requests actually mean and how to find the real cause — this error's family across 28 libraries.

Related errors

• Failed to list all tables under namespace ${namespace}
• Metastore operation failed for %s.%s
• Could not find lock with HMSClient {}
• Failed to unlock {}.{}
• Failed to connect to Hive Metastore

AI-assisted analysis of apache/iceberg@86d9c8fc54 (2026-09-12). Data as JSON: /api/errors/5fff0a8df16e3a37. Report an issue: GitHub.