Deployments in a Clustered Scenario

Before the process engine starts to perform a deployment, it tries to acquire an exclusive lock on a row in the table . When the process engine is able to acquire the lock successfully, it starts to deploy and holds the exclusive lock as long as the execution of the deployment take place.

Additionally, the exclusive lock ensures that multiple definitions (e.g., process definitions) with the same key don’t get the same version when they are deployed simultaneously, which can lead to failures and unexpected behavior. Note that there is no unique constraint in the database that checks the uniqueness of a definition.

By default, the exclusive lock acquisition is enabled. If this is not desired, it is possible to disable it by setting the process engine configuration flag named deploymentLockUsed to false.