apache/dolphinscheduler · error · IllegalMonitorStateException

Etcd lock count has gone negative for lock:

Error message

Etcd lock count has gone negative for lock: 

What it means

Thrown in EtcdRegistry.releaseLock when the per-thread re-entrant lock count for the key drops below zero: the code is releasing a lock more times than it acquired it (unbalanced unlock), or the LockEntry state was corrupted. It signals a caller-side lock-protocol violation rather than an etcd failure.

Source

Thrown at dolphinscheduler-registry/dolphinscheduler-registry-plugins/dolphinscheduler-registry-etcd/src/main/java/org/apache/dolphinscheduler/plugin/registry/etcd/EtcdRegistry.java:396

     * release the lock by revoking the leaseId
     */
    @Override
    public boolean releaseLock(String key) {
        try {
            Map<String, LockEntry> lockEntryMap = threadLocalLockMap.get();
            if (lockEntryMap == null) {
                return true;
            }
            LockEntry lockEntry = lockEntryMap.get(key);
            if (lockEntry == null) {
                return true;
            }
            int newLockCount = lockEntry.lockCount.decrementAndGet();
            if (newLockCount > 0) {
                return true;
            }
            if (newLockCount < 0) {
                throw new IllegalMonitorStateException("Etcd lock count has gone negative for lock: " + key);
            }
            client.getLeaseClient().revoke(lockEntry.leaseId);
            lockEntryMap.remove(key);
            if (lockEntryMap.isEmpty()) {
                threadLocalLockMap.remove();
            }
        } catch (Exception e) {
            throw new RegistryException("etcd release lock error, lockKey: " + key, e);
        }
        return true;
    }

    @Override
    public void close() throws IOException {
        // When the client closes, the watch also closes.
        client.close();
    }

View on GitHub (pinned to 02eac45a1b)

Solutions

1. Audit callers to ensure every releaseLock is paired with exactly one successful acquireLock on the same thread
2. Avoid releasing locks in finally blocks when acquire may have failed
3. Check for double-release paths (e.g. nested try/finally both calling releaseLock)

When it happens

Trigger: Thrown at dolphinscheduler-registry/dolphinscheduler-registry-plugins/dolphinscheduler-registry-etcd/src/main/java/org/apache/dolphinscheduler/plugin/registry/etcd/EtcdRegistry.java:396 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of apache/dolphinscheduler@02eac45a1b (2026-09-06). Data as JSON: /api/errors/2a5c6d45161838c2. Report an issue: GitHub.