Shreedhar' s Weblog

JavaOne2008: Shoal Mini Talk at Java.Net Community Corner

At the JavaOne pavilion, Java.net had set up a community corner where mini talks were given by various interested project leads. I gave a short talk on Introducing Shoal clustering framework. 

The audience was *very* small  but I had quality questions from one very interested participant who wanted to use Shoal as a Distributed Test Harness engine. Very unique use case I thought and yes, Shoal would fit that bill.

Here's the short slide deck of the mini talk: Shoal Mini Talk JavaOne 2008

Posted at 04:50PM May 09, 2008 by Shreedhar Ganapathy in Shoal  |  Comments[0]

JavaOne 08: JavaU Bonus course on GlassFish Application Server

As part of JavaU courses offered this JavaOne, a GlassFish Application Server bonus training course was offered for free as part of a multi course deal. 

Many attended this course on Monday, May 05, 08. Arun Gupta and I  presented at this course. We are pleasantly surprised by the turn out of around 180 given that it was in the evening (6 - 9 pm), 3 hours long, and JavaOne had not yet started! That was surely a boost of positive energy for me.

The most interesting part of the course for me was the number of questions from the greatly interactive audience right from the get go. We answered most of the questions, even picked up an NB issue from an audience member in the web services area, and the feedback we received was mostly that the course was very helpful for the audience to understand how the product features and capabilities stacked up with their experience with other app servers such as WebLogic and JBoss.

We finished around 9.45 pm.

Since the printed slide deck was only a portion of the total at the time it went to print, I promised the audience that I would make this available through my blog.

So here it is. JavaU Bonus Course on GlassFish Application Server Java One 2008

So for those who find the material useful, please download GlassFish and let us know what you think. Send us your comments and questions through the GlassFish User mailing list.  

Posted at 04:38PM May 09, 2008 by Shreedhar Ganapathy in General  |  Comments[1]

New Shoal Clustering Download Page

With a view to helping our users choose the right download, we have organized the Shoal downloads page on the lines of the GlassFish download page. The new download page is located here : https://shoal.dev.java.net/downloadsindex.html

This should make it easier for users to find Shoal bits and use them in their clustering applications.We are seeing increasing interest from users with different types of questions in the Shoal user mailing list ranging from newbie questions to very advanced ones. Keep'em coming folks.

We will be posting new promoted downloads  and releases through this download page. Let us know if you need specific improvements to be made.

Posted at 12:23PM Apr 18, 2008 by Shreedhar Ganapathy in Shoal  |  Comments[0]

GlassFish High Availability Session at Sun Tech Days Hyderabad

At the recent Sun Tech Days event at Hyderabad, I gave a talk covering GlassFish's High Availability features, particularly the In-Memory Replication support, as part of GlassFish Day (Feb 29th). 

I had the privilege of talking to a full house of around 500 people. The session covered introduction to HA, how easy it is to create, and configure a cluster of instances, and to configure the application for enabling in-memory replication based availability. The session elicited very good questions ranging from the basics to involved ones in the area of sizing the heap to sticky sessions support. I spent an hour after the session outside the hall answering questions posed by interested folks from several companies.

Many attendees wanted to get a copy of the slide deck. Look here for it.

Needless to say, we would very much appreciate any feedback or questions on GlassFish's High Availability. Please send these to us at the GlassFish user mailing alias.

Posted at 05:00PM Mar 12, 2008 by Shreedhar Ganapathy in GlassFish  |  Comments[2]

Notes from GlassFish Booth at Sun Tech Days, Hyderabad '08

I am back after a two week visit to India. I took the week off last week to be with my folks and to unwind and recharge in my home city, Mumbai.

The week before that was an incredible one for me as I saw the hi tech boom in India first hand. The swelling and enthusiastic crowds at the Sun Tech Days event at Hyderabad on Feb 27, 28 and 29 was very thrilling to experience to say the least. The event was highly successful in attracting budding youngsters and experienced professionals alike. I am told that the content of the event was very fulfilling for attendees.

Some notes of interest :

• Each session had between 1000 and 1500 attendees. Community Day was on Feb 29th with tracks such as GlassFish, OpenSolaris, Netbeans, etc. and each track had an expected 450 people based on hall capacity. In the GlassFish track, we saw that increase to around 500.
  

• At the GlassFish booth, I met quite a lot of visitors many of whom had either vaguely heard about GlassFish or never heard of it. About a 3rd of people were ones who work with an Application Server in a professional capacity. Others were developers learning the ropes at work or students who were excited to see an open source appserver like GlassFish.

• GlassFish is relatively new here - people have heard about it and are now beginning to try it out. So this was a huge opportunity to spread the word about GlassFish as a compelling open source project delivering a fully Java EE 5 compliant application server packing a whole bunch of features that commercial vendors usually provide for the cost of an expensive license and services attachment.
  

• Many professionals I talked to had tried JBoss before but due to their employer or customer platform preference, they were on WebSphere or WebLogic.
  They were impressed with GlassFish's Administration ease of use and GlassFish's published SpecJ numbers.
  

• Companies from which people came to booth read like the who's who of the hitech majors' list such as Wipro, Satyam, Infosys, Cap Gemini, etc.

• Most users were still developing on J2EE 1.4. Many are beginning to move to Java EE 5.

• Many developers I met were on Eclipse. I demoed GlassFish and NetBeans 6.0 when possible at the booth and many went back saying they will surely try NB with GF.
  

• GlassFish's open source status
• Free for development and deployment
• No license fee for product purchase
• Strong community support
• Sun's backing and commercial support offering (the concept of indemnification was new for some but many understood impact for their customers abroad)
• Administration ease of use
• Market leading product differentiators such as Grizzly, Virtual server support in Web tier, Web Services support, Easy cluster creation and management, Call Flow Monitoring, High Availability Options through In-memory replication and HADB, Inclusion of a quality MQ product, Netbeans and Eclipse IDE integration, etc.
  
  

Many of the professionals working with other application servers said the Administration, Clustering, High Availability, Loadbalancer support, Webservices support, migration support, and IDE integration would motivate them to try out or switch to GlassFish. 

Looking forward to hearing from these new GlassFish users at our user community mailing list.

Posted at 06:32PM Mar 11, 2008 by Shreedhar Ganapathy in GlassFish  |  Comments[0]

Sailfin drives a new feature in Shoal: JoinedAndReadyNotificationSignal

As usage of Shoal's clustering framework increases across products, new feature requests are coming in to enrich Shoal's offerings for employing applications.

The Sailfin project is building a Telecommunications Application Server with contributions from Ericsson and Sun. One of the parts of Sailfin is a Java based load balancer called ConvergedLoadBalancer (CLB). The CLB load balances both Http and SIP based requests. The CLB is unique in that it is a component of the Sailfin appserver instance. Thus, any instance in the cluster can be configured as a load balancer. Such an instance can be part of a Front End LB Cluster performing load balancing of requests on a separate application server cluster tier or it can be part of a Self LoadBalancing Cluster wherein one or more instances of the application server cluster also perform the role of a load balancer while also serving requests. The CLB component and other Sailfin components employ Shoal for cluster events, messaging and health monitoring.

The CLB (as with any load balancer) needs to know when instances of a cluster have not only joined a cluster but also when the instances are ready serve requests. Shoal was up until now providing a JoinNotificationSignal which would be triggered as soon as each instance in the cluster used Shoal's GMS to join the cluster. This was sufficient for many use cases but for the LB it needed to know not just that but also when the instance had completed startup operations. This requirement helped us design a new notification called JoinedAndReadyNotificationSignal that would be disseminated to the cluster members for each instance completing startup and reporting such a completion to the group.

Shoal's GroupManagementService provides a new API called reportJoinAndReadyState() which the employing parent application can now call when the parent application has completed its own initialization and startup indicating a point where operational activities on the instance can now start.

Sheetal and I recently committed the code supporting this new feature.

This feature can be particularly useful while building Compute Grid and Cloud Computing type services using Shoal wherein each Grid node can now report when they are ready to act as nodes in the grid. BTW Shoal's concept of  a GroupLeader ties in well with the Grid's Compute Task Manager abstraction and is a good infrastructural fit.

Do please share your feedback with us at users alias about what you would like to see added in Shoal to serve your clustering and fault tolerance needs. Shoal's goal of clustering goes much beyond the realm of Data Grids (which we are looking into building ) with a wider  spread in terms of building fault tolerance solutions.

Posted at 08:30AM Jan 17, 2008 by Shreedhar Ganapathy in Shoal  |  Comments[8]

GlassFish Hidden Nugget: Automatic Distributed Transaction Recovery Service

GlassFish v2 and v2 ur1 releases (and later) have support for transaction recovery (both manual and automated) in the sense that incomplete transactions at the time of an instance failure can be committed either manually or automatically.

Posted at 02:16PM Jan 11, 2008 by Shreedhar Ganapathy in GlassFish  |  Comments[0]

Excellent Article on Shoal by non-Sun authors

Just came across this excellent introductory article on Shoal clustering framework on Java.net which I believe is to be published on upcoming Tuesday going by the date posted (12/11/2007).

Noticeably, this is an article by authors that we, at the Shoal community, have not yet corresponded with. This is great news as it lets us know that there is a quiet adoption of this framework. The article lucidly explains salient aspects of Shoal's clustering approach and how easy it is to integrate it into your application/infrastructure. 

We hope this will make it even easier for users to adopt this technology.

Do send us your questions at the Shoal users mailing list.

Posted at 01:53PM Dec 08, 2007 by Shreedhar Ganapathy in Shoal  |  Comments[1]

Shoal Whitepaper on Scalable Dynamic Clustering

Its been a while since I have blogged. I have been rather busy managing the GlassFish v2 ur1 release which is round the corner around Dec 13/14.

Meanwhile, Mohamed Abdelaziz and I put together a Whitepaper that gives details on the scalability and dynamic clustering aspects of Shoal. The paper provides a good overview of the self composing nature of Shoal and dives deeper into the set of protocols that provide the basis for building fault tolerant infrastructures.

Shoal is coming along very well in various spaces going by the increasing hits to our website from Telco and Financial majors. We are continuously improving Shoal into a robust component based on feedback from our user community. So keep'em coming to the users mailing list.

Posted at 06:59PM Dec 05, 2007 by Shreedhar Ganapathy in Shoal  |  Comments[0]

Shoal Clustering User Guide Part 1

In this series of blog entries, I will provide a guide for new users on how to use Shoal for your application.

This particular blog entry provides a Shoal Clustering 101 type basic introduction. Subsequent blogs will enable the user to get more closer to the metal on how to use this technology.

What is Shoal? 

Shoal is a technology/framework that allows consuming applications the ability to participate in a group and thereby communicate with the group, register interest in being notified of group events, and share application data across group members. These functionalities enable Shoal to be used as a clustering framework in enterprise infrastructure software while also being capable of other use cases.

Shoal's core is the Group Management Service (GMS) which provides client APIs to interact with a group while allowing group communication libraries to be integrated through a service provider interface implementation. Currently with a Jxta service provider, Shoal takes advantage of advanced Jxta features for robustness, reliability and scalability.

While Shoal itself is scalable to many instances in a group (upto 64 nodes in our tests), the scaling is always determined by the size and characteristics of the employing application/product.

Shoal Downloads  

Among the first things you want to know is where to get Shoal downloads.  

Shoal download is available here. Pick the latest zip file for the latest and greatest stable version. The zip file contains two jars of interest - the shoal-gms.jar containing Shoal's client api, GMS core implementation, and a Jxta service provider implementation,  and jxta.jar which is the Jxta peer-to-peer platform.

Shoal Documentation 

Now that you have the jars, you would need documentation to see how to integrate Shoal into your product. Shoal offers APIs to consuming applications to participate in a cluster. Shoal's JavaDocs containing the APIs are available here. In the JavaDoc, select the com.sun.enterprise.ee.cms.core package.  Look in the Description section for a simple introduction to the API.

As the Description mentions, the GMSFactory class located in the com.sun.enterprise.ee.cms.core package is the entry point for getting Shoal's Group Management Service.

Code Snippet 

The following code snippet uses the GMSFactory to start the GMS module, use the GroupManagementService reference to initialize the group, register interest in events,  join the group and the api to call when the process is ready to leave the group : 

//initializes GMS and underlying group communication provider

final GroupManagementService gms = GMSFactory.startGMSModule(serverIdentifierName, groupIdentifierName, GroupManagementService.MemberType.CORE, configProperties);

//register for group events

//register to receive notification when a process joins the group
gms.addActionFactory(new JoinNotificationActionFactoryImpl(this));

//register to receive notification when a group member leaves on a planned shutdown
gms.addActionFactory(new PlannedShutdownActionFactoryImpl(this));

//register to receive notification when a group member is suspected to have failed
gms.addActionFactory(new FailureSuspectedActionFactoryImpl(this));

//register to receive notification when a group member is confirmed failed
gms.addActionFactory(new FailureNotificationActionFactoryImpl(this));

//register to receive notification when this process is selected to perform recovery operations on a failed member's resources
gms.addActionFactory(serviceName, new FailureRecoveryActionFactoryImpl(this));

//register to receive messages from other group members to this registered component

gms.addActionFactory(new MessageActionFactoryImpl(this), componentName);

//joins the group
gms.join(); 

//leaves the group gracefully
gms.shutdown(GMSConstants.shutdownType.INSTANCE_SHUTDOWN); 

As the above code snippet shows, it is extremely easy to instrument Shoal into your application and be on the road to clustering your application and take remedial actions on occurrence of group events.

A Simple Shoal Example (sources)

Look through this example code to see the full source of a Simple Shoal Example.  Look in the runSimpleSample() method to understand steps to make Shoal an in-process component.

Questions? Comments? 

If you have questions on the above, please send your questions to the Shoal users alias: users [at] shoal [dot] dev [dot] java [dot] net or post your questions as a comment to this blog entry.

In the next blog entry, I will go a bit deeper explaining specific parts of Shoal.

Posted at 05:53PM Aug 14, 2007 by Shreedhar Ganapathy in Shoal  |  Comments[10]

Shoal Clustering Framework 1.0 Early Access available

Its been a fairly long time since I blogged.

Over the past few months, we (the GlassFish HA team and the Jxta Team ) have been concentrating on improving and addressing GlassFish high availability features and associated bugs. In the process, Shoal's Group Management Service benefited from intensive QE cycles on 8-node GlassFish clusters under scores of scenarios and test cases. We have been focused on fixing bugs, improving performance, and progressively gating changes in Shoal to manage risks for the upcoming GlassFish v2 FCS release. 

At the moment, Shoal is in good shape and we decided to release the Shoal 1.0 Early Access version a couple of days ago. This will be followed by the 1.0 Final release before the GlassFish v2 release once we know that we have delivered the final acceptable bits for that product.

After that our next step is to address the unique requirements that arise out of the Sailfin project which is building a SIP supported application server based on GlassFish.  

We'd love to hear feedback from our user community about your success stories, issues and enhancement requests using Shoal.

We have seen anecdotal evidence of how useful and easy-to-use this library is and it would help improve our adoption and project growth if more specific feedback is available. Our Statcounter statistics are showing companies from very interesting industry segments going through the Shoal site, downloads and documents so this is a huge boost to our commitment to build a good group communications API based library.

If you have a success story or feedback using Shoal that you can share, drop us a line at the Shoal user alias

users[at]shoal[dot]dev[dot]java[dot]net

and we will highlight it our blogs and on the Shoal web site.

Also we welcome code and design contributions from experienced clustering and distributed systems developers.

Posted at 05:29PM Aug 07, 2007 by Shreedhar Ganapathy in Shoal  |  Comments[0]

Safari on Windows XP, Initial thoughts

Just downloaded Safari beta for Windows XP and was earlier writing this blog entry using it before moving back to FireFox.

The Javascript widgets at the blogs.sun.com editor do not show up as this is not a supported browser. I wish Roller would show the widgets on a best effort basis.

Upsides:

The rendering quality and speed is awesome. Absolutely blazing fast on my home DSL connection. And the look and feel is very smooth and pleasing. Has Tabbed viewing support. Renders RSS feeds on a site with a single click and looks very nice. Has popup blocker, and most features that FireFox.

Downsides:

Commonly used sites sometimes dont work with Safari beta on Windows. Seems to have problems with forms. Hotmail, YahooMail, did not work in my experience (to its credit, web 2.0 sites such as dzone.com, upcoming.org worked well).

On this blog entry being written on Safari, in the end it did not allow me to post the blog or save it as draft. The buttons just would not work.

I hope these bugs get addressed soon.
Looking forward to the final version. Wish Firefox were as fast and smooth! Oh well, a little competition is good for all products.

Posted at 09:34AM Jun 12, 2007 by Shreedhar Ganapathy in General  |  Comments[0]

NetBeans and GlassFish clusters:What are your needs?

We are looking for feedback from users of NetBeans and GlassFish on what they would like to see in terms of their runtime interactions through the IDE with cluster(s) in GlassFish.

Most IDEs provide the ability to work with a single instance of an application server such as GlassFish, etc.  I do not see the notion of cluster(s) in the IDEs unless I have missed something obvious. There must be various use cases wherein a developer (typically an advanced developer/deployer/tester such as a System Integrator) would need the ability to interact with a cluster through the IDE.

Clustering typically involved an environment consisting of many instances that can be located on different remote machines. Such instances are created/started/stopped/deleted on each machine by a dedicated agent process that follows instructions from an administrative server within which a cluster is a logical configuration entity while instances are physical entities. So, within the IDE, there are possibly but a few operations that can be executed/managed.

So here are some questions for which I'd appreciate responses through comments (Add more if you can think of any further):

1. Is there indeed a need for interacting with clusters through the IDE?
   
2. What problems do you see today with respect to clusters from within your IDE?
   
3. If the browser based admin console of the appserver can be lauched from within the IDE would this  be sufficient to address your needs?
   
4. If not, why is the IDE an important piece to help solve that problem?
   
5. If interacting with cluster(s) is important, what should that interaction functionality be from within an IDE?
6. If debugging seems like an obvious use case, would that not already be addressed by working with individual instances that are part of a cluster?
   
7. What other use cases do you work with that you wish an IDE could provide when working with clusters?
   

Do add more questions and answers if you can think of more.

Posted at 10:03AM Mar 31, 2007 by Shreedhar Ganapathy in NetBeans, Other IDEs  |  Comments[1]

Article on Introducing PetStore 2.0

Posted at 08:53AM Mar 27, 2007 by Shreedhar Ganapathy in Blueprints  |  Comments[0]

Blueprints team delivers Web 2.0-based PetStore 2.0 application

The Blueprints team has delivered a brand new (early access but mostly complete)  version of the popular PetStore application.

What's different about this release is that this application demonstrates the use of latest emerging technologies (popularly called Web 2.0) and uses the more mainstream pattern preference of developers, that of a web-only application that employs the JPA for persistence. As a result, the PetStore 2.0 is a significantly lightweight yet rich web application that shows how to mesh Java EE 5 artifacts with emerging technologies such as AJAX, mashups, etc.

Petstore 2.0 can be viewed live on Sun's Developer Web site located at http://webdev1.sun.com/petstore/faces/index.jsp. The announcement of the release is located at https://blueprints.dev.java.net/servlets/NewsItemView?newsItemID=4632.

The Petstore 2.0 application demonstrates numerous Web 2.0 uses cases in the application including Ajax, Client-side mashups, Server-Side mashups, Delegated mashups, RSS news bar through ROME, File upload and much more. Petstore 2.0 is part of the Java EE 5 SDK and runs on Glassfish. The release notes for Petstore are located at https://blueprints.dev.java.net/petstore/release_notes.html.

If you are a developer looking for resources and guidelines on how to build AJAX and other web 2.0 technologies enabled Java EE apps, download the PetStore and review the code base. The code is released under the BSD license and is reusable in your apps.

You can also discuss your questions at the blueprints forum located at : http://forum.java.sun.com/forum.jspa?forumID=121 

Posted at 11:34AM Feb 14, 2007 by Shreedhar Ganapathy in Blueprints  |  Comments[0]