Re: [dna-users] Minimum system requirements for using DNA

We have not done any benchmarking to obtain actual measurements with different configurations. So all I can offer at this time are rules of thumb. In short, the better the machine, the easier it will be. But please keep in mind that JBoss DNA is actually a pretty lightweight system, and I suspect the content will very soon outweigh the overhead of the JBoss DNA engine. The minimum requirements are pretty low, especially when compared with the minimums for the JRE. The only disk space that is required is that necessary for the JAR files, and any room for persistent storage (e.g., local or embedded database, files, etc.) would have to be added to this. Similarly, the only RAM required is that necessary to run the JRE plus hold the JcrEngine and repository objects in memory. Of course, the OS's virtual memory configuration will also influence the disk space and RAM requirements. Needless to say that the practical minimums are almost entirely driven by the JBoss DNA configurations: the number of repositories, the number of node types, the number of namespaces, the number of repository sources, how those sources manage their state (e.g., in- memory sources keep it in memory, whereas JPA repository sources might persist in a local database and may use Hibernate's second-level cache, etc.). But these metrics will also depend very much on how the JCR clients are written: how many concurrent sessions are open, how much information is cached in each session, how much information is changed between calling 'save(), and whether the JCR clients hold onto the nodes obtained from sessions. (The latter, btw, shouldn't be too bad, as the objects that are returned outside of the JCR interfaces are essentially flyweights, and we've carefully designed the system so that clients holding onto these objects should not affect how the sessions manage their own memory.) As for CPUs and hard drive (speed), I think the basic rule is "the faster, the better". The surest way to identify the minimums are to test JBoss DNA running with a representative configuration and a representative amount of content. Best regards, Randall On Sep 29, 2009, at 1:14 PM, Aaron Pestel wrote: