Uncaught TYPO3 Exception: #1561445710 Could not acquire exclusive lock (blocking+exclusive)

[bh-teufels]

I use reddis Cache for femanager user registration an get following error if users has the same IP.
user get error "Too many attempts from this IP address. Try again later." in the frontend.
in Backend Error log it says "Uncaught TYPO3 Exception: #1561445710 Could not acquire exclusive lock (blocking+exclusive)"

Is there a security setting or something which limits the connections from one IP?
is it possible to deactivate or change the limit?

[bmack]

Maybe femanager uses locking as well, and should be less restrictive? The IP limitation definitively comes from that extension, not by distributed-locks

[htuscher]

We experience the same issue periodically. We are running a big cluster instance with multiple workers and heavy cache usage:

Core: Exception handler (WEB): Uncaught TYPO3 Exception: #1561445710: Could not acquire exclusive lock (blocking+exclusive). | TYPO3\CMS\Core\Locking\Exception\LockAcquireException thrown in file /app/vendor/b13/distributed-locks/src/RedisLockingStrategy.php in line 175

But we aren't able to trace down the root cause.
If it's stuck in that state the only thing that helps is redis-cli FLUSHALL

[bitwelle]

With TYPO3 13 and the version 2.0.0 we also run into the same problem in a kuberntes environment.
We were also unable to find the cause. TYPO3 11 and version 1.4.0 had no problems previously. As mentioned, we couldn't locate the problem, and the code changes didn't seem to provide any explanation for the behavior.

[JBlocks]

I can confirm the mentioned behavior with T3 v13 in an Azure Redis Cluster.

T3 v13.4
PHP v8.5
Redis Cluster (Azure)
Redis version: 7.4
Clustering Policy: OSSCluster

[...]
at TYPO3\CMS\Core\Locking\ResourceMutex->acquireLock('pages', '224_62ed06578260b2d3')
[...]

(1/1) #1561445710 TYPO3\CMS\Core\Locking\Exception\LockAcquireException
Could not acquire exclusive lock (blocking+exclusive).