Blogging Roller

• Patrick Peak is back and considering switching to Webwork2.
• Integrating Struts, Tiles, and JavaServer Faces: interesting article I found via Rafe.
• Avalon: a new UI for Windows: nice analysis of Microsoft's new UI architecture and further links to articles on the topic.
• Eclipse Emerges from Microsoft's shadow: Eclipse is starting to pose a serious threat to Visual Studio (or Active Dot Net Studio or whatever it is called today).
• Janne Jalkanen is readying a new version of JSPWiki - a "huge change with a large number of of new features."
• Paid by the keystroke: Charles Miller uses a brief example to compare the brevity of Smalltalk, Java, Perl, Python, Ruby, and others.
• Programming fonts: nice looking fonts for your code editor.

I am now obligated to paint 13 fishies, 2 smiling crabs, 2 sea-horsies, 2 sea anemone, 2 starfish, and one big and goofy looking clownfish on a kid-sized table for the school's fund raising auction. Why did I draw so many creatures... what was I thinking?

First there was ASP, then JSP and PHP, then Struts, now there is JavaServer Faces, which has been years in the making and is Java's answer to .Net's Web Forms, offering the prospect of highly useable data grids and other controls. It also goes well beyond that role by providing a sophisticated control model for web applications that exceeds .Net's capabilities. JavaServer Faces can also be combined nicely with Struts.

I'm working my way through the JSF spec and wishing it was here now, so I'm really sorry I'm going to miss this one. Jay Cagle team lead of the Websphere Studio web tooling group will be presenting on JSF tomorrow night See the RTP-WUG site for details.

That was a lot of fun. Thanks Mark!

is happy and I'm going to go canoeing. See you next week.

continues to dig in to the Roller source to identify, correct, and suggest workarounds for Roller bugs. Soon, we'll need a 0.9.8.1 release soon to incorporate his fixes. Good work Lowem!

Continuing on the childish theme, my 6-year old son Alex claims to have invented and popularized this silly chant at his school: "kids are the best, we know true, put us all together and we shout BOO!"

That's right, Java/J2EE is a minivan. It is not sexy or hip like Ruby or Python. It is sensible, practical, gets the job done, and is relatively easy on the software industry environment. C#/Dot-Net, of course, is the SUV: crass, macho, and a real environmental hazard, especially to endangered species soon to be Redmond roadkill like Borland, Ximian, SourceGear, etc.

A number of people have asked how Freeroller suddenly became so fast and so stable. The answer is Roller 0.9.8. Freeroller had been running Roller 0.9.7, which had a history of performance and stability problems from the start.

The first problem we experienced with Roller 0.9.7 wasn't noticed by the users, but our gracious hosts at The Javalobby noticed an unusually high load on their server coming from the Roller and MYSQL processes. Later, as the number of bloggers blogging and readers visiting the site grew, users started to notice unpredictable behavior. Spurious 404 errors, sluggish performance, and frequent downtime started to irritate everybody.

Roller 0.9.8 seems to have resolved all of these problems. Let's take a look at the changes made since Roller the initial 0.9.7 release starting with the changes that were applied to Freeroller before the Roller 0.9.8 upgrade:

• Caching weblog update times. Because Roller uses page caching, most content is served out of the page cache and for most requests there is almost no need to hit the database. For most requests we only hit the database to bump up hit counters and to determine last-update-time for RSS newsfeeds. Still, Roller was killing MYSQL and the load from Roller and MYSQL was dragging the Javalobby server down. Since RSS newsfeeds account for more than 60% of all traffic, I decided to cache those last-update-times. Javalobby noticed an improvement in load, but load was still a little high.

• The Open session in view pattern. With new users signing up every day and a number of more high-profile bloggers starting to draw in the hits, Freeroller really started to drag and users started to notice. The Roller development team started to wonder "what have we done wrong?" We eventually concluded that Roller uses too many persistence sessions, which roughly correspond to database connections, per request. Lance implemented the open session in view pattern in the Castor and the Hibernate persistence implementations in the Roller main branch. I backported the changes to the Roller 0.9.7 branch and deployed them to Freeroller only to find a minimal performance increase.

• OSCache 2.0-beta upgrade. Around that time, the OSCache team relased a beta of OSCache 2.0 and Hani told me that the old OSCache was rubbish and had a terrible memory leak, so I switched Roller and Freeroller over to the new OSCache, configured it for memory caching plus unlimited disk cache, and noticed a pretty big leap in performance and decrease in system load. Still, the stability was poor and spurious 404s continued.

Those changes were important changes, but they did not fix the performance and stability problems. Now, let's move on to the changes that were added by the Roller 0.9.8 upgrade:

• Numerous small fixes. While I was fussing with Freeroller and Roller 0.9.7, Lance and Min were looking for further performance improvements in the Roller 0.9.8 branch. Min fixed the Roller calendar control to keep it from hammering the database as it use to. They both worked to change the persistence layer interfaces to return lists instead of arrays, since both Castor and Hibernate return lists, list to array conversions are just silly in this case.

• Database indices. At some point during Roller 0.9.8 development somebody (Jim Smart?) contributed a patch for the Roller database creation script and added indices where indices were missing. I didn't think much of it at the time, but this was a pretty significant change.

• Hibernate/JCS caching. Freeroller was getting worse and worse, even causing Freeroller founder Anthony Eden to leave and, believe it or not, even causing the Hibernate team to feel the heat. Some were suggestingthat perhaps Hibernate did not scale. Gavin King stopped by the Roller dev-list and suggested that we try using proxies and JCS caching. I didn't get far with proxies, but it was easy to turn on JCS caching. Unfortunately, JCS caching by itself didn't seem to help much.

So, what change made the big difference in performance? It can't have been only update-time caching, open session in view, and OSCache 2.0 changes because they were all in place before the Roller 0.9.8 upgrade. It can't have been Hiberate/JCS caching because stress testing showed that JCS actually slowed down the system a bit. All of these fixes played a part in the performance improvements, but because of the greatly reduced load on MYSQL I think the database indices made the biggest difference.

The Roller vs. WebloggerZilla fiasco ended peacefully.

This new Roller release provides a dramatic performance increase due to addition of database indices, proper use of persistence sessions, and a new version of OSCache. New features include Weblog.com ping and integrated Lucene weblog search. Thanks to all that helped out with the release. For details, see the change notes. You can download the release from the project's SourceForge download page.

I can't believe that people feel the need to rag on Gavin King, the lead developer of Hibernate, because he joined the JBoss Group. They say he "sold out" and joined the dark side. What a crock. Do we really have to break up into JBoss, CDN, Open Symphony, and Jakarta camps and sling mud at each other? No, we don't! And really, who wouldn't quit their day job when they finally find a way to make their night job pay? There is no reason be upset, people. Unless, of course, they start charging for Hibernate docs. Then, my friends, heads will roll.

has gone too far, matey.

The FreeRoller performance and stability problems seem to be behind us, so I'll be making a the Roller 0.9.8 release this weekend. A number of people have asked how we achieved the dramatic performance increase on FreeRoller, so I'll try to summarize the performance fixes that were made between 0.9.7 and 0.9.8 in a later post.

The lights have been flickering and the cable modem has been dropping in and out, but I continue to work and the kids continue to enjoy the first of two days off. The wind and rain are supposed to be the heaviest from 3PM to 6PM here in Raleigh. From where I sit, I can see a big stand of tall oak and pine trees whipping around in the wind. I'm hoping that things don't get any more exciting than this.

is the word of the day in more ways than one. Confluence is a new web-based knowledge management and group collaboration application apparently built upon concepts from on content management, weblogging systems, and wikis. Developed by Atlassian, the company that developed the popular Java-based JIRA bug tracker and java.blogs, Confluence is currently in alpha testing.

Today was cool and clear fall day here in North Carolina. No sign of the approaching storm. I live in Raleigh which is a couple of hundred miles from the shore, but the storm could track close enough to us give us a dose of 60 mile-per-hour winds, power outages, and downed trees. I'm hoping that the two giant oak trees in our yard will survive and will not land on our house. My hurricane preparations? I stowed all of our lawn furniture, bought extra charcoal for the grill, and bumped up the maxProcessors thread-count on FreeRoller from 75 to 200 threads.

I walked out to my mailbox today to find that FreeRoller has vaulted everybody's favorite blowhard, the Howard Stern of Java blogs, bile-blogger Hani Suleiman to worldwide fame in the pages of Java Developers Journal. Hani's editorial, is just another in a series of unnecessary open-source-ain't-all-it's-cracked-up-to-be pieces from JDJ. The motivation for this most recent open source backlash? I guess JDJ feels the need to please it's advertisers and Hani feels the need to poke a little stick in the eyes of the JBoss group and Andy Oliver.

I've been googling around for some guidelines for setting the number of request-processing threads on a Tomcat site. So far, I've found nothing. FreeRoller had been set for 75 threads, but it seems to run out at that level. Does this by itself indicate a problem or is 75 threads too low for a relatively high volume blog site like FreeRoller?

I just realized that I am sitting in a chair that was given to me by the now CTO of Amazon.com. He also gave me a computer and a "pink slip." I'm not bitter. It is a quite comfy chair.