Hi Zoltán,
Like stated in the docs, you can implement a custom HistoryEventHandler which writes the events to a JMS queue and add it to the ProcessEngineConfiguration by either creating a Process Engine Plugin (when using a shared engine) or directly set it on the ProcessEngineConfigurationImpl when you are bootstrapping the engine as part of an embedded engine approach.
The engine uses the DbHistoryEventHandler as default implementation to write the history to the database.
You can also extend the class CompositeDbHistoryEventHandler to log to other sources in addition to the database.
We do not provide async history logging out of the box and I was unable to find an example for it in our repositories.
Does this answers your question?
Cheers,
Christian