J2EE Clustering with Tangosol's Coherence

Last night I attended the local Boston Java Meetup Group to get a sense of what my technology cousins are up to since most of my conversations are always in Macromedia-centric arenas.

The most interesting part of the evening for me was meeting Cameron Purdy. Cameron was obviously the Java guru at this table of Java gurus. It turns out that Cameron is president of Tangosol, a company in Somerville which he founded. Tangasol's flagship product Coherence is a type of J2EE clustering software which appropriate for storing extremely large quantities of data in memory and replicating it across large numbers of J2EE cluster members while handling thousands of data updates per second.

Coherence is described in various contexts as:

Tangosol Coherence enables in-memory data management for clustered J2EE applications and application servers. Coherence makes sharing and managing data in a cluster as simple as on a single server. It accomplishes this by coordinating updates to the data using cluster-wide concurrency control, replicating and distributing data modifications across the cluster using the highest performing clustered protocol available, and delivering notifications of data modifications to any servers that request them.


and

... provides scalable performance and is not compromised by single points of failure ... [and] manages many gigabytes of data and thousands of updates per second ... self partioning architecture without single points of failure or measureable GC pauses ...


That last quote is about as much as I could jot down while watching this presentation on Coherence while trying to keep up with Cameron's break-neck reading velocity. As an aside, this presentation was hauntingly similar to a Breeze presentation, but actually used a similar product from Articulate.

This large scale clustering software appears to be significantly more robust than the JINI-based clustering found in Macromedia JRun. Replication of session data across small JRun clusters is generally thought to have a noticible performance impact and its typically recommended to minimize the data that is replicated in this manner to unique keys that act as pointers to persistant data on the backend databases. A couple reviews of JRun clustering are available for comparison:

CFMX 7 Verity Error: com.verity.organize.WorkSpaceException

When creating collections in ColdFusion MX 7 via the Administrator or code, you might encounter the following error:

Unable to create collection {collection name}.
An error occurred while performing an operation in the Search Engine library.
Error opening the collection: com.verity.organize.WorkSpaceException: Path not found [VdkError_PathNotFound]. (-104)


The Verity collection directory tree contains a subdirectory called ws to act as a work space during collection creation. When that directory starts to accumulate directories and files, Verity may report this WorkSpaceException.

The work space directory on a "Server Configuration" installation would be
$CFHOMEverityDataservicesColdFusionK2_indexserver1ws
whereas if Verity was installed in J2EE configuration on WebSphere on Windows for example the Verity work space directory would be
{driveletter}ColdFusionSearchServiceDataservicesColdFusionK2_indexserver1ws
where the Verity bits were laid down in the ColdFusionSearchService directory as a sub-installation routine.

To resolve the exception and create Verity collections again, stop the ColdFusion MX 7 Search Service, remove all the contents of the ws/ directory, then start the Search Service.

Seeking Mach II Presenter for May 12 Online ColdFusion Meetup

The new Online ColdFusion Meetup Group has hit the ground running with a few successful meetings so far, including Webapper's SeeFusion, a talk on CFForm Enhancements by Simon Horwith with follow-up by Mike Nimer, and the first talk on CFMX 7 on Unix/Linux by me.

While there are some additional special events in the works in cooperation with the mangers of physical CFUGs, I'm trying to build the speaker series for the regularly scheduled OCFMG talks and keep the momentum going.

The Meetup polls taken so far indicate that after the rich forms, the most popular topic is Mach II.

If you have indepth Mach II experience and would like to share that information with a group of online attendees via Breeze, please let me know. I'd like to secure a speaker for the May 12th meeting (time negotiable) to discuss an introduction to Mach II. At a later date, it would be great to have a higher level presentation, too.

Please contact me offline or post a comment if you're interested, and I'll follow up. Thanks!

Today! SeeFusion presented by Mike Brunt of Webapper

The Online ColdFusion Meetup Group invites you to a virtual presentation on the ColdFusion monitoring tool, SeeFusion, Thursday April 14, 2005 at 6:00 PM EDT. (Timezone Info)

This meeting has been completed. If you missed it, you can still check out the archive to watch the talk, demos, and discussion all with recorded live audio http://mmsupport.breezecentral.com/p39006045/

SeeFusion, available at http://www.seefusion.com, is described as:

"... a utility for monitoring ColdFusion application servers. SeeFusion gives you the ability to "see" how your ColdFusion servers are processing requests in real time., ... SeeFusion tracks 3 types of requests--currently running requests, recently completed requests, and recently completed long-running requests. In addition to providing detailed request monitoring, SeeFusion also offers a JDBC "wrapper" feature for obtaining detailed information about database interaction., ... SeeFusion is virtually undetectable as an overhead process on the server. It's implemented as a low-level servlet filter, which allows SeeFusion to provide valuable metrics even (and perhaps especially) on high-traffic production servers."


From the About page on http://www.webapper.com:
"Webapper is a grouping of Web development professionals strategically located throughout the world. The core of the Webapper team is made up of Web application specialists from the world's leading ColdFusion/Web application consultancythe former Allaire Consulting Services. Several former Allaire developers joined forces to create Webapper, bringing you the best knowledge available for your ColdFusion applications in particular, and for your Web applications/Web sites in general.


What's a virtual meeting like? Check out this archived presentation on CFForm Enhancements by Simon Horwith.

For more info on how to participate, see this blog entry.

Tonight! CF's XML Capabilities and CFForm Enhancements

The Maryland CFUG in cooperation with the new Online ColdFusion Meetup Group will have 2 speakers starting at 6:30pm US Eastern time tonight! The meeting will be broadcast via Breeze and you're welcome to join.

Douglas Ward will present CF's XML Capabilities, followed by Simon Horwith's CFForm Enhancements.

The meeting URL is http://mmsupport.breezecentral.com/r59782284/

More information is available at:
http://www.talkingtree.com/meetup/ and
http://coldfusion.meetup.com/17/events/4500245/

Don't forget to check out CFUnited 2005, the premier ColdFusion conference run by TeraTech's industrious Michael Smith.

CFMX 7 Podcast Series: Clustering and Sourceless Deploy

Second in this series of podcasts is a reading of the Macromedia Devnet article on managing clusters by Geoffrey Greene and Erik Tierney.

Managing Clusters with Enterprise Manager and Packaging Applications in ColdFusion MX 7
Package and deploy EAR and WAR files, and manage instances and clusters with the Enterprise Manager.


To subscribe to the ColdFusion podcasts you can set your podcast-enabled blog aggregator such as iPodderor Feed Demon to the ColdFusion Podcast RSS 2.0 feed.>.

This sound quality of this podcast is an improvement over my first now that I'm using a professional microphone, although it was a challenge to complete the reading since I'm just recovering from a cold where I lost my voice last week. After having read Jake Ludington's article titled, Create Podcasts Using Your PC, I decided that the toy microphone that had sitting around wasn't going to cut it and I would need something better. I used his article on creating a podcasting kit as a guideline.

I purchased a microphone and a pre-amp at a Guitar Center in Natick for a much better price than anywhere online. I couldn't find a cheap mini compressor anywhere so I decided to opt out of that. The service at Guitar Center was great a gentleman named Alain explained everything I would need to know from how to use a pre-amp to which buttons to push and where to plug in the various wires.

Updated Connector Hotfix for CFMX 6.1 Updater - cflocation issue corrected

The recent technote Macromedia ColdFusion MX 6.1 Updater: Hot Fix to upgrade web server connectors has been updated today with a new hotfix version that corrects a problem with cflocation that was introduced with an earlier hotfix build. If you experienced the cflocation problem, then this hotfix should help you out.

Related CFTalk thread.

Obsessed with Blogging?

At 10 pm, my wife walks into the living room and sees me on the couch with the widescreen laptop illuminating the walls.

She says with a sigh, "my husband ... the blogger".

I tried to explain the whole getting blogged by Dave Winer thing... she didn't get it.

Podcast Unto Others, As You Would Have Others Podcast Unto You

O'Reilly blogger Jake Ludington published the second article in a series about podcasting. I'm skimmed them so far and I'm about to give them a careful read since they appear to be clear and comprehensive.

Podcatch.com - A directory of cool stuff for the podcasting community

Blogging's Founding Father, Dave Winer, who first envisioned podcasting, has launched a new site tonight, Podcatch to act as a respository of knowledge for the podcasting community.

I commented on his initial post about my intentions to start podcasting Macromedia technical content, move on into interviews and such, and then reach out into creative podcasting when my experience matures.

Dave picked up on my comments and blogged it on Scripting News, where he relates to my experience as one of those moments where the lights suddenly go on.

Check out this one hour interview with Dave on IT Conversations. He discusses his first course in computing after following his father's advice, to starting his first business, running Userland Software, developing XML-RPC, SOAP, RSS, and podcasting. If you're not listening to IT Conversations regularly, you should be!

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