L3 - Default The class org.camunda.bpm.engine.impl.persistence.deploy.DeploymentCache caches deployed resources (BPMN, CMMN, DMN models) and can be accessed by multiple threads in parallel. Internally it uses HashMaps. HashMaps are not thread-safe (e.g. chance for infinite loops when putting in parallel, see http://javaeesupportpatterns.blogspot.de/2012/08/java-7-hashmap-vs-concurrenthashmap.html).
Probability of problem occurrence: very low (apparently no user ever had one so far, at least we did not notice)
Worst-case damage: rather high (users might violate SLAs they give to the users of their process applications)
This is the controller panel for Smart Panels app
[CAM-4867] Deployment Cache is not thread-safe
According to the linked article, the difference between HashMap and ConcurrentHashMap isn't too big and that would at least solve the infinite loop possibility.
Perhaps we should also think about testing parallel access to the DeploymentCache which would make us aware of concurrency issues in our own code.
We are closing this ticket as part of our backlog grooming. Reasons:
- This problem does likely not exist anymore
We should fix this with as limited impact on performance as possible.