JBoss Cache 2.0.0.GA is out and as you can see from Manik's last entry, we're already moving forward...and fast. Before JBoss Cache 2.0 is forgotten, let's have a quick glance at some hidden gems that came within it:
1.- Singleton Cache Store Functionality
Cache stores are backend stores for data handled within JBoss Cache. Until now, the main two strategies to configure these cache stores were:
- sharing a cache store between all JBoss Cache instances.
- each instance having its own cache store.
When cache loaders, which interact with cache stores, are configured for singleton store, only the JBoss Cache instance in the coordinator of cluster interacts with the cache store. The rest of nodes replicate changes to the coordinator which is in charge of putting them in the store. When such coordinator leaves the cluster, or stops working, a new coordinator is elected which takes charge of communicating with the cache store. This allows for only one JBoss Cache instance to interact with the cache store at a time.
More information on Singleton Cache Store functionality and configuration options can be found in the JBoss Cache 2.0 documentation.
2.- Transforming Cache Loaders
In JBoss Cache 2.0, the format of the data stored in the File and JDBC cache loaders has been changed so that it uses the JBoss Cache marshaling framework, created to improve replication efficiency, to format data to be stored in these cache stores.
At JBoss, division of Red Hat, we think about our product's end users and when implementing such data format change, we realised that some of JBoss Cache's users might have populated cache stores in JBoss Cache 1.x format. Even though JBoss Cache 2.0 is a major release, we wanted to provide our a way to transform existing cache stores from 1.x format to 2.x format. Because of this, we created a set of one-off Transforming Cache Loaders whose job is:
- read data from cache stores the way we did in JBoss Cache 1.x
- write data to cache stores in JBoss Cache 2.x format.
The Transforming Cache Loaders, necessary libraries to understand JBoss Cache 1.x and example mentioned can be found within the JBoss Cache 2.0.0.GA distribution ZIP file that can be downloaded from here.
More information on Transforming Cache Loaders can be found in the JBoss Cache 2.0 documentation.