Month: October 2012

What’s going on with Alfresco clustering?

I am way past due getting this blog post out. We’ve had multiple discussions on the topic in #alfresco on IRC over the last several weeks, but I want to make sure those of you who aren’t yet hanging out in IRC regularly are aware of some changes related to Alfresco clustering that have already happened with the 4.2.a release. In general, I would prefer to share this stuff way ahead of any release in which it takes effect, but that didn’t happen this time and I’m sorry about that. I promise to try to do better!

With that out of the way, let me shed some light on some recent changes that may affect some of you running Community Edition…

Until recently, clustering in Alfresco has been implemented using a combination of three main technologies: Ehcache, Hazelcast, and JGroups. If you’ve looked at it lately, you may have noticed that JGroups has been removed from the repository source code. What’s going on is that we are consolidating our clustering implementation on Hazelcast because it can handle everything we need to make clustering work. (On a side note, I believe this is one of those improvements that we’ve made to our on-premise software as a result of lessons learned running our own large-scale Alfresco implementation in the cloud).

So that explains what’s going on with clustering in the Enterprise Edition. But if you looked closely at the Community Edition source code, you may have noticed that Hazelcast is no longer included at all. In fact, all clustering related codeĀ (org.alfresco.repo.cluster.*) has been removed, including configuration files like cluster-context.xml and hazelcast/* and some changes to existing Spring configuration.

Now, at this point, some of you are probably thinking, “There was clustering code in Community Edition? I didn’t think clustering was supported in Community Edition.” You are correct. Clustering has never been supported in Community Edition. Community Edition is not commercially supported by Alfresco at all. But a lot of the pieces you need to make clustering work in Community Edition have been available until now, and there may be people out there who chose to get it working themselves rather than pay for an Enterprise subscription that includes support for clustering. These recent changes make it much harder to do that.

What I want to make sure everyone is clear on is that the removal of the ability to cluster Community Edition does not represent a shift in our philosophy on what should be in Community Edition versus what should be in Enterprise Edition. The principles John Newton outlined in his blog post, “Building a stronger open source product” back in 2009 still apply today. In short, functionality that supports large-scale rollouts (like clustering) or that depend on paid “Enterprise” software (like Oracle and WebSphere) should be Enterprise-only while everything else should be available to the community.

So rather than a change in philosophy, the removal of the clustering code from Community Edition simply implements the existing philosophy more explicitly. To be blunt, if your implementation is critical enough to require the 7×24 up-time an active-active, multi-node cluster provides, you should be able to justify an Enterprise Edition subscription. If you have high availability requirements but your rollout is relatively small or cost is an issue, perhaps Alfresco in the Cloud will be a fit.

Of the estimated 100,000+ installations of Community Edition currently up-and-running, my hunch is that this change affects only an infinitesimal fraction. But if you have feedback on this change, please do let your voice be heard, either here or by sending me email directly at jeff dot potts at alfresco dot com.



Screencasts of my favorite Alfresco 4.2 Community Edition features

I wrote up a list of some of my favorite new features in Alfresco 4.2 Community Edition in this blog post over at But I saved the best stuff for you, my loyal reader: Screencasts showing those favorite features in action! Don’t worry, these are short and to the point. Hopefully just enough of a taste of each feature to get you to download Alfresco 4.2 Community Edition and try it out for yourself.

So without further ado, here are screencasts of my favorite new features in 4.2 Community (be sure to switch to full screen to enjoy their HD splendor)…

The new and improved Google Docs integration is very cool. I have a feeling this is going to be popular.

And how about that new Rich Media Gallery view in the document library? This is just one of multiple new document library views coming down the pike if I’m not mistaken. You can use the same extension points Ray used to create your own custom document library views.

There are a few new dashlets (Saved Search, Site Search, My Discussions) and some enhancements to existing dashlets (Image Preview, My Tasks).

Here’s one I’ve heard requested multiple times: Can I select multiple documents and download them as a zip? Boom. It’s in there. Another new document action is “Quick Share” which Alfresco in the Cloud users have been enjoying for some time. Now it’s available on-premise.

All of these screencasts were based on an October 8 nightly build using the binary installer. There may be some differences between what is shown here and what is in the final release.

So there you go folks. Download the new Community Edition release, try it out, and give us your feedback. I believe the plan is to have at least one more Community Edition release before DevCon. So you should definitely make it a point to try it out before you show up in Berlin or San Jose in November. That way you can slap these Engineers on the back for all of the great work they’ve put into this release!

The Public Alfresco API is Now Live: How to Get Started

At JavaOne this morning, Alfresco announced the general availability of the public Alfresco API. The public Alfresco API allows developers to create custom applications (desktop, mobile, or cloud) that persist content to Alfresco in the Cloud. The API includes CMIS plus some Alfresco REST calls that provide functionality CMIS does not cover.

Eventually, this public, versioned API will work against Alfresco in the Cloud as well as Alfresco running on-premise. For now, it is only for Alfresco in the Cloud, although the CMIS calls will work against both. (For example, on my flight to California I worked on an example using CMIS and my local repository. When I got to the hotel, I added in the OAuth authentication and my example worked against Alfresco in the Cloud).

To use the Alfresco API, all you have to do is become a registered developer at Once you’ve verified your email address, you can add applications to your profile. Each application has a unique authentication key and a secret. OAuth2 is used to handle authentication.

Once you have your authentication key and secret, you can start making calls against the API. Calls that hit the Alfresco REST part of the API return JSON. Calls that leverage CMIS return AtomPub XML. If you already know how to make CMIS calls, you already know how to use the Alfresco API–just grab the latest version of your favorite CMIS client, like OpenCMIS or cmislib, and pass in the authorization header. I believe you must use the 0.8.0-SNAPSHOT of OpenCMIS. If you are using cmislib, you’ll definitely need 0.5.1dev.

Here are some resources to help you get started:

If you want to discuss the public Alfresco API, use this forum and any of our other normal community channels like #alfresco on IRC or the Alfresco Technical Discussion Google Group.

Of course we’ll be talking about the API at DevCon in both Berlin and San Jose this November, so don’t forget to register!

Also, Peter Monks and I will be doing this month’s Tech Talk Live on the new API, so if you weren’t lucky enough to be in San Francisco for our session at JavaOne or our booth, you can catch the details there as well.