Martin kindly explained: Each processor has its own logical journal, although journal plugins > maintain them in a single physical backend store (replicated or not). This > is not a requirement but all plugins follow this pattern so far. So, from a > physical viewpoint there's a single big message store but this doesn't mean > that there is a global ordering of messages. An ordering of messages is > only defined within a processor (i.e. logical journal). Messages from > different processors are seen as unrelated by akka-persistence.
This event log is per processor (optionally with n views as subscribers). > The reason that there's no global log (with a global ordering of messages) > is write scalability: processors can reside on different nodes and having a > global counter for all would limit scalability. An interesting alternative > could be information about causal ordering of messages between processors > (not implemented (yet)) and this could be implemented in a scalable way. > One of the benefits I perceived from eventsourcing was having this global event log to, perhaps, assist with debugging and possibly with analytics. I understand a truly global log would limit scalability but is it not possible to (somewhat weakly) order events by a timestamp (understanding the limitations of that as well). That said, causal ordering of messages between processors sounds very interesting and is probably a much more reliable approach. Cheers, Ashley. -- >>>>>>>>>> Read the docs: http://akka.io/docs/ >>>>>>>>>> Check the FAQ: >>>>>>>>>> http://doc.akka.io/docs/akka/current/additional/faq.html >>>>>>>>>> Search the archives: https://groups.google.com/group/akka-user --- You received this message because you are subscribed to the Google Groups "Akka User List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.
