In the blog entry “GlassFish ESB v2.2 Field Notes – Exercising Load Balanced, Highly Available, Horizontally Scalable HL7 v2 Processing Solutions”, at https://blogs.czapski.id.au/?p=13, 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 ” at https://blogs.czapski.id.au/wp-content/uploads/2010/03/GFESB_LB_HA_Demo_Session_SWF.swf (62.7Mb download)
Jan 05
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
or
b. Request/Reply Web Services
or
c. JMS in Request/Reply mode
2. implement business logic as short lived processes
3. are
a. atomic
or
b. are idempotent
or
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 complete Note is available as 03_Conducting_HL7_LB_and_HA_Exercise_v1.0.0.1.pdf at https://blogs.czapski.id.au/wp-content/uploads/2010/03/03_Conducting_HL7_LB_and_HA_Exercise_v1.0.0.1.pdf
Jan 03
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. 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.
This note walks through the process of installing a GlassFish ESB v2.2 runtime on the Base OpenSolaris-based VMware Virtual Appliance, discussed in the Blog Entry “GlassFish ESB v2.x Field Notes – Preparing Basic JeOS Appliance for GlassFish ESB LB and HA Testing” at https://blogs.czapski.id.au/?p=15.
At the end of the Note we will have a GlassFish ESB VMware Appliance with GlassFish ESB Runtime infrastructure, ready to use for GlassFish ESB Load Balancing and High Availability testing, or any other purpose for which a GalssFish ESB runtime appliance might be appropriate.
The complete note is available as 02_Installing_GlassFishESB_on_JeOS_appliance_v1.0.0.1.pdf at https://blogs.czapski.id.au/wp-content/uploads/2010/03/02_Installing_GlassFishESB_on_JeOS_appliance_v1.0.0.1.pdf
Jan 03
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 frequently a wrong assumption. Load Balanced (LB) and Highly Available HA) SOA and Integration solutions may not require that degree of complexity and sophistication. 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.
This note walks through the process of building a Base OpenSolaris-based VMware Virtual Appliance, based on the JeOS Prototype. It will be used as the underlying infrastructure in future Notes discussing building GlassFish ESB, Java MQ, MySQL and other appliances used in LB and HA testing. The major advantage of this infrastructure is that, as well as being fully functional, if is free (as in free beer).
At the end of the Note we will have a basic VMware Appliance, running the minimal, headless OpenSolaris Operating System (based on June 2009 JeOS Prototype), configured to use NAT networking, and ready to use as the basis of GlassFish ESB and other infrastructure. To accomplish this we will download the JeOS Prototype, configure machine name and NAT networking and test network connectivity. We will also discuss the steps required to clone this appliance.
The complete walkthrough is available as 01_Preparing_baisc_JeOS_appliance_v1.0.0.3.pdf at https://blogs.czapski.id.au/wp-content/uploads/2010/03/01_Preparing_baisc_JeOS_appliance_v1.0.0.3.pdf.
