Tuesday Aug 31, 2010

Oracle SOA Suite 11g R2 B2B - Receiving a Stream of Multiple HL7 v2 Message Types

In this article I discuss and illustrate a “SOA-less” solution in which the Oracle SOA Suite 11g R2 B2B receives a stream of different HL7 v2 delimited messages types (A01 and A03) using a single inbound adapter. The messages are converted into their “equivalent” HL7 v2 XML messages. I say “SOA-less” because all the work is done entirely within the B2B part of the SOA Suite – no OSB or SOA Composites are involved.

The complete text of the article is availabloe at http://blogs.czapski.id.au/wp-content/uploads/2010/08/07_Oracle_SOA_Suite_B2B_Receiving_Stream_of_

Wednesday Jan 27, 2010

Recording of a dmonstration of the "GlassFish ESB v2.2 Field Notes - Exercising Load Balanced, Highly Available, Horizontally Scalable HL7 v2 Processing Solutions"

In the blog entry "GlassFish ESB v2.2 Field Notes - Exercising Load Balanced, Highly Available, Horizontally Scalable HL7 v2 Processing Solutions" I present the GlassFish ESB v2.2-based load balanced, highly available, horizontally scalable solution for HL7 v2.x delimited messaging, using both the HL7 Binding Components, Web Services and JMS in request/reply mode. The one and a half hour recording of me discussing and demonstrating this solution is available as a Flash Movie (SWF), "GFESB_LB_HA_Demo_Session SWF " through the blog article Recording of a dmonstration of the “GlassFish ESB v2.2 Field Notes – Exercising Load Balanced, Highly Available, Horizontally Scalable HL7 v2 Processing Solutions” at http://blogs.czapski.id.au/2010/01/recording-of-a-dmonstration-of-the-glassfish-esb-v2-2-field-notes-exercising-load-balanced-highly-available-horizontally-scalable-hl7-v2-processing-solutions

Saturday Jan 09, 2010

GlassFish ESB v2.2 Field Notes - Ephemeral, JVM-global, POJO-based Sequence Number Generator for BPEL

When working on the HA solutions discussed in my HA blog ebntry I realized that it will be difficult to work out whether messages are delivered in order, as was required, and whether any are missing. I got over the issue by ensuring that my test data was prepared in such a way that messages in each test file had increasing, contiguous sequence numbers embedded in the message. For HL7 v2, which is the messaging standard with which I dealt, I used MSH-10, Message Control ID field. I wrote processed messages and acknowledgments to files whose names embedded MSH-10 Message Control Id, with the sequence number, so breaks in sequence and out of order messages could be readily detected.

With multiple message files containing between 1 and 50,000 messages, adding a sequence number to each message by hand was clearly out of the question.

I put the GlassFish ESB to use. I constructed a file-to-file BPEL module project to read each test file and to prepend a sequence number to each message’s MSH-10 field. The only snag was how to get a sequence number that would start at 0 and increase by 1 for each message, such that each BPEL process instance would get the next sequence, and that messages would be written to the output file in order.

This note discusses how I went about accomplishing the task.

The original article is available as GlassFish ESB v2.2 Field Notes – Ephemeral, JVM-global, POJO-based Sequence Number Generator for BPEL at http://blogs.czapski.id.au/2010/01/glassfish-esb-v2-2-field-notes-ephemeral-jvm-global-pojo-based-sequence-number-generator-for-bpel

Tuesday Jan 05, 2010

GlassFish ESB v2.2 Field Notes - Exercising Load Balanced, Highly Available, Horizontally Scalable HL7 v2 Processing Solutions

It seems frequently assumed that architecting and deploying Highly Available (HA) solutions requires Application Server and/or Operating System clustering. When it comes to SOA and Integration solutions this is not necessarily a correct assumption. Load Balanced (LB) and Highly Available HA) SOA and Integration solutions may not require that degree of complexity and sophistication. Frequently, protocol, binding component, JBI and architectural application design properties can be exploited to design highly available solutions. Testing LB and HA solutions requires infrastructure consisting of multiple hosts and the ability to “crash” hosts at will. With virtualization technologies available now it is far easier to use multiple virtual machines then to use physical machines. It is also easier and potentially less destructive to “crash” virtual machines then it is to do so with physical machines.

In this Note a heterogeneous, non-clustered collection of hosts will be used to implement and exercise three load balanced, highly available GlassFish ESB-based solutions. The environment consists of a number of independent “machines”, which are not a part of an Operating System Cluster. Each “machine” hosts a GlassFish Application Server. Application Servers are independent of one another and are not clustered. This is to demonstrate that load balanced, highly available, horizontally scalable solutions, based on the GlassFish ESB software alone, can be designed and implemented.

The specific class of solutions to which this discussion applies is the class of solutions which:
1.    are exposed as request/reply services
a.    HL7 messaging with explicit Application Acknowledgment
b.    Request/Reply Web Services
c.    JMS in Request/Reply mode
2.    implement business logic as short lived processes
3.    are
a.    atomic
b.    are idempotent
c.    tolerant of duplicate messages
Classes of solutions with characteristics different from these named above require different approaches to high availability and horizontal scalability, and are not discussed here.

In this Note only high availability and scalability of receiver solutions is addressed. This aspect is the focus because a failure to process a message by a receiver may result in message loss –generally a bad thing.

Paradoxical as it may sound; senders are special cases of receivers. Just as a receiver is triggered by arrival of a message so too is a sender. Making sure that the sender trigger message does not get lost is much the same as making sure the message a receiver receives does not get lost. This means that the same considerations apply to senders and to receivers.

This note discusses an exercise involving an example load balanced, highly available, horizontally scalable healthcare environment, processing HL7 v2 messages. Discussion includes customization of generic GlassFish ESB v2.2 VMware Virtual Appliances for a specific Load Balancing and High Availability exercise and deploying ready-made GlassFish ESB solutions. The exercise for HL7 BC-based, Web Service-based and JMS-based highly available, load balanced, and horizontally scalable receivers, processing HL7 v2.3.1 messages, will be conducted and discussed.

At the end of the Note we will have three GlassFish ESB VMware Appliances with GlassFish ESB v2.2 Runtime infrastructure, ready to use for further GlassFish ESB Load Balancing and High Availability exercises.

The reader will be convinced, one hopes, that for the applicable class of GlassFish ESB-based solutions, load balancing and dynamic failover without message loss work. For that class of solutions this provides for high availability and horizontal scalability without resorting to Application Server or Operating System clustering.

The article is available at http://blogs.czapski.id.au/2010/01/glassfish-esb-v2-2-field-notes-exercising-load-balanced-highly-available-horizontally-scalable-hl7-v2-processing-solutions

In this Blog I post abstracts of articles / writeups / notes on various aspects of Java CAPS and SOA Suite including solutions, discussions and screencasts. The links to the referenced material are included in the bodies of the abstracts.


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