Journal.IO 1.3 released


Just a moment ago (in February 17th) Journal.IO 1.3 has been released. Journal.IO ( is a lightweight, zero-dependency journal storage implementation written in Java. We use it in our project for storing application events (Event Sourcing pattern). It is a good, stable solution if you want to have simple in use event storage e.g. if you want to implement lightweight queuing mechanism and JMS is overhead for you.

New version resolves some bugs and improves delete operation performance. Unfortunately new version uses new log format which isn’t backward compatible. Therefore we decide to write a simple migrating tool for migrate 1.2 version compatible logs to 1.3 version.


Migrator was written in groovy. It is available on github ( Also link to the tool is available from official Journal.IO homepage. To use it simply run:

oldLogsRoot is recursively scanned for logs which are migrated parallel in 5 threads (used ASYNC read mode additionally speed up this process). Migrated logs are written in the same hierarchy in newLogsRoot.