Welcome!

Microservices Expo Authors: Ruxit Blog, Elizabeth White, Liz McMillan, Pat Romanski, Roger Strukhoff

Related Topics: Microservices Expo

Microservices Expo: Article

SOA Feature Story: Real-Time SOA Starts with the Messaging Bus!

The mediator of all component interactions

Service Oriented Architectures are increasingly being used to implement high-performance and real-time systems. Traditional systems operate in "human real-time," where human patience is the limit. Increasingly, however, systems operate in "computer real-time," where the only limits are imposed by the operational speed of the computers and networks.

For example, next-generation Air Traffic Management systems are being developed to accommodate the huge increase in air traffic and link the operational capabilities of agencies such as the Federal Aviation Authority, the Department of Defense (DOD) and the Department of Homeland Security (DHS). These systems require higher information bandwidth (to track more aircraft or more complex "free-flight" trajectories) as well as much lower latencies or delays on the information (to detect flight abnormalities quickly). Similar demands are being made in healthcare, SCADA, network monitoring, energy distribution, transportation, and other critical infrastructure systems.

Best-of-Breed SOA Components
Demanding real-time applications require best-of-breed service-oriented foundational components. There are three kinds of foundational components in a SOA system: A messaging fabric/bus, information transformation/processing engines, and persistence/storage services (see Figure 1). Often these components are integrated into an Enterprise Service Bus (ESB) and hosted in a J2EE Application Server.

Of these foundational components, the Messaging Fabric/Bus is the most critical, since it mediates all interactions between components.

Low-performance SOA systems may use HTTP as the "messaging fabric/bus" to exchange messages between components. This approach is only suitable for non-demanding applications: HTTP isn't reliable, has limited bandwidth, introduces very high latencies, and can't buffer and queue messages and deliver them to systems that are either temporarily unavailable or join at a later time.

The solution is to deploy a high-performance messaging middleware such as RTI Data-Distribution Service, IBM WebSphere MQ, TIBCO, or SonicMQ. These middleware platforms have been developed with scalability and performance in mind. However, they each employ a different architecture optimized for different application scenarios.

Why Does Messaging Performance Matter?
The requirements and expectations of computer-speed real-time far exceed traditional human-speed real-time. Whereas in systems with a human in the loop, real-time meant that the information was available anywhere from fractions of a second to few seconds in the computer-to-computer world, real-time means decisions should be made in milliseconds or even microseconds.

Computer real-time puts more stringent requirements on the messaging infrastructure: Each processing and storage component must get hundreds of thousands of messages/events per second with microsecond or at worst millisecond latencies. This means that the messaging middleware must be able to deliver millions of messages a second system-wide.

And the capacity of the messaging fabric must be able to scale with the capacity of the underlying hardware and not impose any limits beyond those of the underlying hardware infrastructure (CPU speed, cores, speed, and bandwidth of the network) itself. As the CPU and network speeds increase those systems able to take advantage of what the hardware provides will deliver a competitive advantage. In an automated trading system, for instance, the critical metric is not the absolute time it takes to make a decision, but rather whether a decision is taken and the trade executed before competitive trades occur. The same is true in a combat management system.

One final aspect of computer real-time SOA systems is their "inverted performance-load utility curve." This means that the ability to respond in a timely manner becomes more important when the system is experiencing a high load. In a normal utility curve, such as in human real-time systems, degraded performance is acceptable under an increased load. This is because human expectations and patience adjust based on the circumstances (e.g., they understand that on a peak holiday period they may endure longer hold times when calling to make a flight reservation). In contrast, computer-speed real-time systems often have the opposite demands. It is precisely at the moments of high load when the "most critical action" is taking place and it is then when it is most critical to deliver top performance (e.g., it is precisely when market action is heavy that trading decisions must be made quickly).

The differences between human-speed real-time systems and computer-speed real-time systems are summarized in Table 1.

Selecting Messaging Middleware in SOA Systems
Messaging middleware is the key enabler of real-time SOA. However, there are many options. How can you choose the best messaging middleware for a particular real-time SOA system? Five areas distinguish messaging middleware: architecture, quality of service (QoS) control and filters, performance-boosting technologies, real-time determinism, and metrics.

Architecture
The four basic architectures employed by messaging middleware are: centralized (hub-and-spoke), clustered, federated, and peer-to-peer. (see Figure 2)

A centralized (hub-and-spoke) architecture routes every message though a single server that implements the message "service," contains all the message queues, and brokers every message.
A clustered architecture uses a collection of servers and assigns to each responsibility for some of the messages (like ownership of some of the message queues or topics). Each message is relayed by a server but not all messages use the same server.

A federated architecture also uses a collection of servers, but it uses them as a "resource pool" where queues may appear in multiple servers, and messages may be brokered by one or more servers.

A peer-to-peer architecture doesn't employ any brokers in the critical path. Messages are routed directly from the sender to the receiver.

Each has strengths and weaknesses. Centralized is easiest to administer and can provide stronger transactional semantics but suffers from poor performance, reduced tolerance to faults, and doesn't scale. Clustered is more scalable than centralized but also has reduced fault tolerance and can only offer good performance in a grid environment with all the clients co-located close to the grid. Federated is more scalable, but suffers from higher latency and jitter as each message is brokered by at least two servers. P2P offers the best scalability, performance, lowest jitter, and highest resilience, but is difficult for vendors to implement and offers limited transactional support.

As demands become more real-time, the need for performance, predictability, and balance tips the scale towards P2P architecture. That's why, for example, demanding networks like Voice over IP and Video over IP (like Skype) use peer-to-peer designs.

Quality of Service Control & Filters
QoS control is critical to deliver timely data with low latency and high throughput. CPU, memory, and network bandwidth resources must be shared among all the traffic. However, not all traffic requires the same bandwidth or has the same urgency or level or criticality. Without QoS control, the application has no way to differentiate different traffic classes and their corresponding constraints. As a consequence, the middleware can't make intelligent decisions, prioritize traffic, or ultimately meet the application requirements.


More Stories By Gerardo Pardo-Castellote

Gerardo Pardo-Castellote, PhD, is chief technology officer of Real-Time Innovations Inc.

Comments (3) View Comments

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.


Most Recent Comments
Gerardo Pardo-Castellote 07/20/08 01:57:08 AM EDT

Regarding the previous comment about "TCP not lining up a message on one connection after a file transfer on another connection." and the "information in the article not being correct."

This is true, but in order for this to occur you would need to open a new TCP connection for every message. This is extremely inefficient, requires a handshake involving a round-trip message, and allocates a lot of system resources. This is certainly something you do not want to do in a real-time system.

So in practice anybody developing a real-time system would have to hold the TCP connection open and send successive messages over it (or course one can keep more than one connection open, and round-robin among them but that does not change fundamental problem if the application is writing quickly). Therefore the information in the article IS correct.

Casual Visitor 06/12/08 03:04:45 PM EDT

TCP does not line up a message on one connection after a file transfer on another connection. Each TCP connection forms its own in-order transfer. If you want to convince people to buy your product, you should avoid putting incorrect information in the article. It is much better to have a good analysis with accurate claims so that people will believe that your product might overcome real problems rather than phantom ones like "messages wait behind file transfers".

Derek Pavatte 01/25/08 02:03:32 AM EST

If everything is automated, I suppose we will have more time to do things more pleasant things than work as much. These technological advancements sound very progressive. Let us all work towards a competent and ethical work environment.
http://www.greatdiamondsforless.com

@MicroservicesExpo Stories
This digest provides an overview of good resources that are well worth reading. We’ll be updating this page as new content becomes available, so I suggest you bookmark it. Also, expect more digests to come on different topics that make all of our IT-hearts go boom!
If you’re responsible for an application that depends on the data or functionality of various IoT endpoints – either sensors or devices – your brand reputation depends on the security, reliability, and compliance of its many integrated parts. If your application fails to deliver the expected business results, your customers and partners won't care if that failure stems from the code you developed or from a component that you integrated. What can you do to ensure that the endpoints work as expect...
SYS-CON Events announced today that Numerex Corp, a leading provider of managed enterprise solutions enabling the Internet of Things (IoT), will exhibit at the 19th International Cloud Expo | @ThingsExpo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Numerex Corp. (NASDAQ:NMRX) is a leading provider of managed enterprise solutions enabling the Internet of Things (IoT). The Company's solutions produce new revenue streams or create operating...
DevOps and microservices are permeating software engineering teams broadly, whether these teams are in pure software shops but happen to run a business, such Uber and Airbnb, or in companies that rely heavily on software to run more traditional business, such as financial firms or high-end manufacturers. Microservices and DevOps have created software development and therefore business speed and agility benefits, but they have also created problems; specifically, they have created software sec...
To leverage Continuous Delivery, enterprises must consider impacts that span functional silos, as well as applications that touch older, slower moving components. Managing the many dependencies can cause slowdowns. See how to achieve continuous delivery in the enterprise.
SYS-CON Events announced today that Tintri Inc., a leading producer of VM-aware storage (VAS) for virtualization and cloud environments, will exhibit at the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Tintri VM-aware storage is the simplest for virtualized applications and cloud. Organizations including GE, Toyota, United Healthcare, NASA and 6 of the Fortune 15 have said “No to LUNs.” With Tintri they mana...
In his general session at 18th Cloud Expo, Lee Atchison, Principal Cloud Architect and Advocate at New Relic, discussed cloud as a ‘better data center’ and how it adds new capacity (faster) and improves application availability (redundancy). The cloud is a ‘Dynamic Tool for Dynamic Apps’ and resource allocation is an integral part of your application architecture, so use only the resources you need and allocate /de-allocate resources on the fly.
Cloud Expo 2016 New York at the Javits Center New York was characterized by increased attendance and a new focus on operations. These were both encouraging signs for all involved in Cloud Computing and all that it touches. As Conference Chair, I work with the Cloud Expo team to structure three keynotes, numerous general sessions, and more than 150 breakout sessions along 10 tracks. Our job is to balance the state of enterprise IT today with the trends that will be commonplace tomorrow. Mobile...
Analysis of 25,000 applications reveals 6.8% of packages/components used included known defects. Organizations standardizing on components between 2 - 3 years of age can decrease defect rates substantially. Open source and third-party packages/components live at the heart of high velocity software development organizations. Today, an average of 106 packages/components comprise 80 - 90% of a modern application, yet few organizations have visibility into what components are used where.
More and more companies are looking to microservices as an architectural pattern for breaking apart applications into more manageable pieces so that agile teams can deliver new features quicker and more effectively. What this pattern has done more than anything to date is spark organizational transformations, setting the foundation for future application development. In practice, however, there are a number of considerations to make that go beyond simply “build, ship, and run,” which changes ho...
Throughout history, various leaders have risen up and tried to unify the world by conquest. Fortunately, none of their plans have succeeded. The world goes on just fine with each country ruling itself; no single ruler is necessary. That’s how it is with the container platform ecosystem, as well. There’s no need for one all-powerful, all-encompassing container platform. Think about any other technology sector out there – there are always multiple solutions in every space. The same goes for conta...
Let's recap what we learned from the previous chapters in the series: episode 1 and episode 2. We learned that a good rollback mechanism cannot be designed without having an intimate knowledge of the application architecture, the nature of your components and their dependencies. Now that we know what we have to restore and in which order, the question is how?
All clouds are not equal. To succeed in a DevOps context, organizations should plan to develop/deploy apps across a choice of on-premise and public clouds simultaneously depending on the business needs. This is where the concept of the Lean Cloud comes in - resting on the idea that you often need to relocate your app modules over their life cycles for both innovation and operational efficiency in the cloud. In his session at @DevOpsSummit at19th Cloud Expo, Valentin (Val) Bercovici, CTO of So...
SYS-CON Events announced today that eCube Systems, a leading provider of middleware modernization, integration, and management solutions, will exhibit at @DevOpsSummit at 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. eCube Systems offers a family of middleware evolution products and services that maximize return on technology investment by leveraging existing technical equity to meet evolving business needs. ...
SYS-CON Events announced today that Commvault, a global leader in enterprise data protection and information management, has been named “Bronze Sponsor” of SYS-CON's 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Commvault is a leading provider of data protection and information management solutions, helping companies worldwide activate their data to drive more value and business insight and to transform moder...
SYS-CON Events has announced today that Roger Strukhoff has been named conference chair of Cloud Expo and @ThingsExpo 2016 Silicon Valley. The 19th Cloud Expo and 6th @ThingsExpo will take place on November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. "The Internet of Things brings trillions of dollars of opportunity to developers and enterprise IT, no matter how you measure it," stated Roger Strukhoff. "More importantly, it leverages the power of devices and the Interne...
Whether they’re located in a public, private, or hybrid cloud environment, cloud technologies are constantly evolving. While the innovation is exciting, the end mission of delivering business value and rapidly producing incremental product features is paramount. In his session at @DevOpsSummit at 19th Cloud Expo, Kiran Chitturi, CTO Architect at Sungard AS, will discuss DevOps culture, its evolution of frameworks and technologies, and how it is achieving maturity. He will also cover various st...
Monitoring of Docker environments is challenging. Why? Because each container typically runs a single process, has its own environment, utilizes virtual networks, or has various methods of managing storage. Traditional monitoring solutions take metrics from each server and applications they run. These servers and applications running on them are typically very static, with very long uptimes. Docker deployments are different: a set of containers may run many applications, all sharing the resource...
Video experiences should be unique and exciting! But that doesn’t mean you need to patch all the pieces yourself. Users demand rich and engaging experiences and new ways to connect with you. But creating robust video applications at scale can be complicated, time-consuming and expensive. In his session at @ThingsExpo, Zohar Babin, Vice President of Platform, Ecosystem and Community at Kaltura, will discuss how VPaaS enables you to move fast, creating scalable video experiences that reach your...
19th Cloud Expo, taking place November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, will feature technical sessions from a rock star conference faculty and the leading industry players in the world. Cloud computing is now being embraced by a majority of enterprises of all sizes. Yesterday's debate about public vs. private has transformed into the reality of hybrid cloud: a recent survey shows that 74% of enterprises have a hybrid cloud strategy. Meanwhile, 94% of enterpri...