eXo JCR 1.8 released

Congratulations to the eXo team for releasing eXo JCR 1.8!

It's cool to see the various JCR implementations evolve and grow. The JCR 1.0 standard is  less than three years old, and there are already a number of independent implementations, both open source and commercial.

So far we've seen little cooperation (apart from JSR 283) or even much direct competition across the implementations, as I guess everyone is just busy grabbing market-share from pre-JCR vendors. But I wouldn't be surprised if we started seeing more benchmarks and feature comparisons on JCR repositories already during this year. I expect it to be fun!

Apache Jackrabbit 1.4 is available!

I just announced the release of Apache Jackrabbit 1.4. The release is the result of about nine months of development since the 1.3 release, and contains 220 new features, improvements, and bug fixes (plus the 75 bug fixes that had already been backported to 1.3.x patch releases). This is by far the biggest Jackrabbit release to date.

The 1.4 release contains some cool new features:

• Friendlier Jackrabbit webapp. The jackrabbit-webapp component now comes with a more polished user interface, better error handling, and improved repository connectivity for local and remote clients.


• Object/content mapping framework. The jackrabbit-ocm component maps Java objects to JCR nodes and vice versa, making it possible to persist normal Java objects in a content repository.


• Service provider interface for JCR. The jackrabbit-spi component defines an architectural layer below the JCR API. The SPI layer is designed specifically for remote access and outlines a way for us to avoid the performance limitations of JCR-RMI that works on top of JCR.


• Optimized storage for binary content. The new DataStore feature in jackrabbit-core avoids all unnecessary copying of binary content and promises huge performance increases for versioning and copying operations. DataStore is a beta-level feature in Jackrabbit 1.4 and disabled by default.


• Improved query engine. The jackrabbit-core component has been extended with new features like configurable indexing, synonym and similarity queries, and spell checking. Many typical queries are now noticeably faster than before thanks to numerous performance improvements.

Many thanks to the Jackrabbit development team and the entire community! I'm really proud and excited to be a member of the Apache Jackrabbit project.

PS. Interestingly enough, I built the final 1.4 release candidate exactly two years after I first volunteered to be the release manager for Apache Jackrabbit. The past two years have certainly been interesting time. :-)

Presenting Apache Tika

Yesterday, during the Fast Feather Track at the ApacheCon US, I presented the incubating Apache Tika project. See below for the slides:

[slideshare id=168085&doc=apache-tika-1195158817320413-4&w=425]

I was positively surprised about the level of attendance and also the interest in Tika during the Search Roundtable BOF later in the evening. Even though the project is still just starting, it's already generating lots of interest and I really look forward to getting the first releases out.

Digital Media at Apache

There's an emerging cluster of digital media projects at the Apache Software Foundation. The Tika and Sanselan projects are currently incubating, and PDFBox is likely to soon follow the example. Together with existing projects like Batik, FOP, POI and the many HTML generators at Apache they form a nice set of tools for consuming, manipulating, and producing various types of digital media.

It would be nice to see also some audio or video processing software entering the ASF...

The Apache Cloud

The heavy concentration of Apache developers here at the ApacheCon US in Atlanta got me thinking about how the various Apache projects are related and whether we could come up with some ways to visualize the existing (and emerging) community patterns.

As a quick first step I just took the committer lists of all Apache projects (excluding meta-projects like Jakarta or Incubator) and ran it through an ad-hoc Perl script that identified any pairs of projects that have five or more committers in common. Running those relationships through Graphviz produced the following diagram:

Interesting stuff... Of course the committer lists are not a very accurate source of information as many committers are no longer active in the projects they once contributed to, so I perhaps should be looking at svn commit logs instead, but as a first approximation the above diagram is already quite nice.

Concurrency and River

If you're interested in concurrency, distributed systems, and ways to best use the manycore processors we're being promised, then check out the Concurrency and River thread on the development mailing list of the incubating Apache River project. The thread is about concurrency and ways the River project (a continuation of Jini from Sun) and related technologies like JavaSpaces could be used to parallellize many computing tasks. There are also some nice comparisons to Erlang and Scala, and how the actor model used by them is related to the Jini network model.

In Hong Kong

I arrived in Hong Kong for the first time in my life two days ago. So far I've only seen the airport, the hotel, and the customer office (yeah, it's been a busy two days) but the weekend is just starting and I'm planning to do some sightseeing in and around the city.

Today I'll do some hiking on the Lantau Trail and try to get a glimpse of Hong Kong Central in the afternoon/evening. Pictures to come...