Dave Klein's Scale Grails Webinar

As someone who spent years in the Smalltalk world I have a special place in my heart for powerful/flexible frameworks and languages that strive for simplicity for the developer. Grails is one of the most powerful and flexible frameworks around and modern representation of those Smalltak values. Some would argue that it's only major missing features are scale-out and HA. The great news on that front is that Grails is built on Quartz, Ehcache, Http Sessions and Hibernate all of which can be scaled with Terracotta in a couple lines of config each. By scaling these four frameworks you can completely scale Grails.

Check out this webinar from the guy who wrote the book on Grails Dave Klein and and learn about it for yourself:

<terracotta clustered="true"/>

One challenge with drastically simplifying Terracotta as a tool for application scale is getting the word out that it's occurred!

The subject of this blog is one of two lines of config and a jar on the classpath that move Ehcache to be a coherent distributed cache. The line of config in the subject says, "Hey, cluster this cache." The other line, which looks something like this:

"<terracottaConfig url="localhost:9510" />"

tells Ehcache where to find the Server Array.

This same story is true for scaling out Http Sessions, Quartz Scheduling and Hibernate Caching. A whole new world of scale is available to the applications we all write. It free's us from complex sharding, awkward CAP trade offs and endless DB tuning. And the cherry on top is it's open source.

No recompile, no code changes, no magic tricks or additional knowledge. I could train my dog to scale an application built on these ubiquitous frameworks.

Check out these blogs to learn more:

Add Scale and HA to Ehcache In Less Than 5 Minutes

Add Scale and HA to Quartz Scheduler In Less Than 5 Minutes

Ehcache 2.1 Beta - Lots of Stuff, Still Backward Compatible

UPDATE: 2.1 went GA March 21st

The Ehcache dev team is pretty excited to be getting 2.1 beta out for the world to try. This release is focused on 3 primary goals:

• Build on our vision of an application scale continuum from one node to the cloud.
• Improve Ehcache performance both unclustered and clustered.
• Improve Ehcache applicability for both unclustered and clustered.

What did we do in the name of these goals? Good question!

Scale Continuum

In this release we are focused on taking features that had been added for the Terracotta Clustered version of Ehcache and extending them back to the unclustered version.

The following features fall into that category:

• The Explicit Locking Module - This module allows you to acquire and release locks manually for given keys. It required some significant rework in the unclustered stores but this now works just as well unclustered as it does clustered supporting fully coherent operations.
• JTA - In 2.0 of Ehcache we added JTA support when clustered via Terracotta. In 2.1 we extended that functionality to unclustered and have begun the process of performance tuning to go along with its XA compliance.

Performance

While performance wasn't a big focus of this release (It is for the next release) we were able to considerably improve Ehcache "put" performance due to the significant work we did on the disk store and locking architecture. We'll also be spending some time tuning JTA but that work did not make it into the beta.

Applicability

Here we did some considerable work.

• JTA for Hibernate Second Level Cache - We added support for using Ehcache JTA in a second level cache both clustered and unclustered.
• UnlockedReadsView - This is a subtle but important feature. For those who are using a coherent cache but have some part of an application that needs to be able to read at high rates without impacting the rest of the cache this view is a huge help.
• NonStopCache - Useful for guaranteeing that your cache can never stop your application. On a per cache basis an application can avoid holdups caused by problems such as a slow disk in an unclustered cache or a network outage in a clustered one.
• New Coherent methods - We've added useful methods like putIfAbsent and replace to simply and easily work with a clustered or unclustered cache in a fully coherent manner. Together with the explicit locking wrapper much is possible.
• We also added a bunch of tests and bug fixes to the web-cache, an extremely useful tool for making performant web applications.

Summing up...

While still in beta we feel like Ehcache 2.1 is another exciting step for our product family. It adds performance, significant features and is still backward compatible. It continues our vision of an application scale continuum from one node to the cloud without burdening the developer with complexity. One set of frameworks, one application, scale out is added at runtime. We are really excited about this vision and are working tirelessly at extending it to all our users' needs.

Please Download Ehcache 2.1 Beta, put it through it's paces and give us lots of feedback!

Application Server Instead Of Web Server

I'm starting to see a small but growing group of sites forgoing web servers and going straight to the Application Server in the Java world. This has some obvious advantages:

• Less infrastructure
• Java doesn't have buffer overflows and is a bit more secure
• You can do much more interesting caching by having the web serving and app serving in the same layer

I was excited to see this blog today and just wanted to point people to it and see what thoughts are out there both pro and con on this trend.

Web Application Architecture - do I really need Apache?

How Much Is Google Really Spending?

This will be a short blog.

Has anyone else noticed that google is using adwords extensively to pimp the nexus one? They must be spending a fortune in lost revenue from other ad sources. Since they don't have to pay for those ads I wonder if even they have an accounting of how much they are spending on this thing. At first I thought the nexus one looked interesting but...

T-Mobile only

No Exchange support

weird app space restrictions

and from what I've read poor touch screen keyboard

On the plus side:

Nice screen

Solid camera with flash

really fast processor

With this kind of marketing muscle it's probably just a matter of time before it gets wide adoption but I suspect it's still a couple years away from being really good.

Clustered Quartz Scheduler In 5 Minutes

Need a fast clustered/persistent Quartz Job Scheduler? Quartz Scheduler, the ubiquitous job scheduler built into Spring, JBoss and Grails can be configured to provide those features in under 5 minutes in this brief tutorial.

A Brief Digression Into The Why

Why do I need a persistent scaled out job scheduler? The main use cases for a clustered/persistent job scheduler are:

• HA - You need to be able to restart your application without losing scheduled jobs
• Scale Out - Your application now needs more than one node to handle the load it receives and you want your scheduled jobs to distribute across nodes.
• You are using a database to persist and or scale your scheduler and you are seeing DB load/locking issues and or you find it two difficult to setup or maintain.

Steps:

1) Download Terracotta 3.2 (Which includes Quartz Scheduler) http://www.terracotta.org/dl/oss-download-catalog

2) Put the following jars in your class path (all included in the quartz-1.7.0 directory of the Terracotta kit from above):

quartz-1.7.0.jar - regular quartz jar
quartz-terracotta-1.0.0.jar - Terracotta clustered store

3) Whip up some scheduler code:

 public class QuartzSample {

public void startJobs() throws Exception {
  Properties props = new Properties();
  props.load(QuartzSample.class.getClassLoader().getResourceAsStream("org/quartz/quartz.properties"));


  // **** Begin Required TC props
  props.setProperty(StdSchedulerFactory.PROP_JOB_STORE_CLASS,"org.terracotta.quartz.TerracottaJobStore");
  props.setProperty("org.quartz.jobStore.tcConfigUrl", "localhost:9510");
  // *** End Required Terrocotta Stuff


  StdSchedulerFactory factory = new StdSchedulerFactory(props);
  Scheduler scheduler = factory.getScheduler();
  scheduler.start();
  if (scheduler.getJobDetail("myJob", "myGroup") == null) {
    System.out.println("Scheduling Job!");
    JobDetail jobDetail = new JobDetail("myJob", "myGroup", DumbJob.class);
    Trigger trigger = TriggerUtils.makeSecondlyTrigger(5);
    trigger.setName("myTrigger");
    scheduler.scheduleJob(jobDetail, trigger);
  } else {
    System.out.println("Job Already Scheduled!");
  }
}

public static class DumbJob implements Job {

  @Override
  public void execute(JobExecutionContext arg0) throws JobExecutionException {
    System.out.println("Works baby");
  }

}

public static void main(String[] args) throws Exception {
  new QuartzSample().startJobs();
}

** NOTE: Notice the two lines of properties that set things up for clustering with Terracotta in the sample. That's the only difference from single node unclustered Quartz.

4) Start the Terracotta server by running start

./start-tc-server.sh

in the bin directory of the Terracotta kit

5) Run the sample code above and watch it run the job every 5 seconds. Then kill the sample app and restart it. The app will tell you that the job is already scheduled and the job will continue.

Conclusion

Two lines of configuration and a server takes you from ubiquitous job scheduler built into Spring, JBoss and Grails to scale out and persistence.

Have fun!

Welcome James House and The Quartz Community

I'm excited to be welcoming James House and Quartz to the Terracotta and Ehcache Fold. The Terracotta dev and field teams have long believed that scheduling and coordination are hugely important parts of applications from single node to scaled out architecture. In Java that leads you to one place. Quartz! We believe James and Quartz are an excellent fit with our community and suite of products that are useful from single node to the cloud.

Quartz Scheduler is both a best of bread and a ubiquitous product. We are getting right to work on contributing. The first step along the path is the Mavenization and Hudsonifaction of the Quartz project which has already been completed! We also are ready with a beta version of Quartz Terracotta Express edition. It's an HA/Durability/scale-out version of Quartz that requires no DB and is so simple it can be leveraged in minutes by existing Quartz users. We look forward to working with James to create the most usable and useful enterprise class open source scheduler available and the enterprise class support product to go with it. We have lots of great feature ideas and we look forward to the journey ahead.