Warning: Corruption of system data

[folch]

Hi,

We are using Modeshape 3.8.0 configured with a Infinispan cache stored in a DB (we used H2, Oracle and MySql) and deployed in an Application Server (we use TomEE 1.6 or Websphere 7.0 or 8.5) and we have found, after some usage, some log entries like this everytime we do a restart of the webapp:

WARNING: The lock with the key "48f1104317f1e7mode:lock-48f11047505d64dd3558c1-d91f-488e-aba4-7b4e97b183ff" cannot be found in the system area and will be ignored. This should not happen and indicates a corruption of the system data.

We haven't observed any loss of functionality and we checked all suspicious nodes and are not locked, but the warning is scaring us a little bit because the number of warnings is increasing as we use the repository.

We are using the LockManager to lock a node to being able to add childs under high concurrency withou issues, but we are using session locks and we are pretty sure that we remove the lock after the node is added. There is no other failure on the log.

Do you have any idea about what is the root cause of that warning? Can we do anything to avoid it? Can we do anything to fix it if ith happens?

Thanks in advance.

[hchiorean]

The message is an indication that locks aren't being properly cleaned up/released from the system area. More precisely, the locks appear as missing from the repository - i.e. they have been deleted - but the parent which owns them still has references to them. This should not affect the repository behavior, but it could be the indication of a bug.

Since you're using an older version of ModeShape, it's hard to tell what the problem is. Ideally, if you can move to the latest ModeShape (4.2) and replicate this behavior, opening an issue would help us track down the problem. It may also happen that this issue has been fixed in ModeShape 4, since we've corrected several lock-related issues([MODE-2190] Lock Garage Collection can cause NPE as locks are removed by sessions - JBoss Issue Tracker, [MODE-2342] Remove lock tokens from sessions upon logout(). - JBoss Issue Tracker, [MODE-2370] Session scoped locks broken in 3.8.x with JTA - JBoss Issue Tracker etc)

In the meantime I've opened https://issues.jboss.org/browse/MODE-2450 and we'll actually cleanup those phantom locks starting with ModeShape 4.3