Microservices Expo Authors: Ruxit Blog, Craig Lowell, Elizabeth White, Liz McMillan, Lori MacVittie

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.

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.

@MicroservicesExpo Stories
This is a no-hype, pragmatic post about why I think you should consider architecting your next project the way SOA and/or microservices suggest. No matter if it’s a greenfield approach or if you’re in dire need of refactoring. Please note: considering still keeps open the option of not taking that approach. After reading this, you will have a better idea about whether building multiple small components instead of a single, large component makes sense for your project. This post assumes that you...
A company’s collection of online systems is like a delicate ecosystem – all components must integrate with and complement each other, and one single malfunction in any of them can bring the entire system to a screeching halt. That’s why, when monitoring and analyzing the health of your online systems, you need a broad arsenal of different tools for your different needs. In addition to a wide-angle lens that provides a snapshot of the overall health of your system, you must also have precise, ...
The 19th International Cloud Expo has announced that its Call for Papers is open. Cloud Expo, to be held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, brings together Cloud Computing, Big Data, Internet of Things, DevOps, Digital Transformation, Microservices and WebRTC to one location. With cloud computing driving a higher percentage of enterprise IT budgets every year, it becomes increasingly important to plant your flag in this fast-expanding business opportuni...
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...
Sharding has become a popular means of achieving scalability in application architectures in which read/write data separation is not only possible, but desirable to achieve new heights of concurrency. The premise is that by splitting up read and write duties, it is possible to get better overall performance at the cost of a slight delay in consistency. That is, it takes a bit of time to replicate changes initiated by a "write" to the read-only master database. It's eventually consistent, and it'...
The burgeoning trends around DevOps are translating into new types of IT infrastructure that both developers and operators can take advantage of. The next BriefingsDirect Voice of the Customer thought leadership discussion focuses on the burgeoning trends around DevOps and how that’s translating into new types of IT infrastructure that both developers and operators can take advantage of.
With so much going on in this space you could be forgiven for thinking you were always working with yesterday’s technologies. So much change, so quickly. What do you do if you have to build a solution from the ground up that is expected to live in the field for at least 5-10 years? This is the challenge we faced when we looked to refresh our existing 10-year-old custom hardware stack to measure the fullness of trash cans and compactors.
The emerging Internet of Everything creates tremendous new opportunities for customer engagement and business model innovation. However, enterprises must overcome a number of critical challenges to bring these new solutions to market. In his session at @ThingsExpo, Michael Martin, CTO/CIO at nfrastructure, outlined these key challenges and recommended approaches for overcoming them to achieve speed and agility in the design, development and implementation of Internet of Everything solutions wi...
DevOps at Cloud Expo, taking place Nov 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 19th Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The widespread success of cloud computing is driving the DevOps revolution in enterprise IT. Now as never before, development teams must communicate and collaborate in a dynamic, 24/7/365 environment. There is no time to wait for long dev...
Thomas Bitman of Gartner wrote a blog post last year about why OpenStack projects fail. In that article, he outlined three particular metrics which together cause 60% of OpenStack projects to fall short of expectations: Wrong people (31% of failures): a successful cloud needs commitment both from the operations team as well as from "anchor" tenants. Wrong processes (19% of failures): a successful cloud automates across silos in the software development lifecycle, not just within silos.
Using new techniques of information modeling, indexing, and processing, new cloud-based systems can support cloud-based workloads previously not possible for high-throughput insurance, banking, and case-based applications. In his session at 18th Cloud Expo, John Newton, CTO, Founder and Chairman of Alfresco, described how to scale cloud-based content management repositories to store, manage, and retrieve billions of documents and related information with fast and linear scalability. He addres...
The following fictional case study is a composite of actual horror stories I’ve heard over the years. Unfortunately, this scenario often occurs when in-house integration teams take on the complexities of DevOps and ALM integration with an enterprise service bus (ESB) or custom integration. It is written from the perspective of an enterprise architect tasked with leading an organization’s effort to adopt Agile to become more competitive. The company has turned to Scaled Agile Framework (SAFe) as ...
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...
Internet of @ThingsExpo, taking place November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 19th Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The Internet of Things (IoT) is the most profound change in personal and enterprise IT since the creation of the Worldwide Web more than 20 years ago. All major researchers estimate there will be tens of billions devices - comp...
It's been a busy time for tech's ongoing infatuation with containers. Amazon just announced EC2 Container Registry to simply container management. The new Azure container service taps into Microsoft's partnership with Docker and Mesosphere. You know when there's a standard for containers on the table there's money on the table, too. Everyone is talking containers because they reduce a ton of development-related challenges and make it much easier to move across production and testing environm...
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...
SYS-CON Events announced today that Venafi, the Immune System for the Internet™ and the leading provider of Next Generation Trust Protection, 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. Venafi is the Immune System for the Internet™ that protects the foundation of all cybersecurity – cryptographic keys and digital certificates – so they can’t be misused by bad guys in attacks...
As the world moves toward more DevOps and Microservices, application deployment to the cloud ought to become a lot simpler. The Microservices architecture, which is the basis of many new age distributed systems such as OpenStack, NetFlix and so on, is at the heart of Cloud Foundry - a complete developer-oriented Platform as a Service (PaaS) that is IaaS agnostic and supports vCloud, OpenStack and AWS. Serverless computing is revolutionizing computing. In his session at 19th Cloud Expo, Raghav...
DevOps at Cloud Expo – being held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA – announces that its Call for Papers is open. Born out of proven success in agile development, cloud computing, and process automation, DevOps is a macro trend you cannot afford to miss. From showcase success stories from early adopters and web-scale businesses, DevOps is expanding to organizations of all sizes, including the world's largest enterprises – and delivering real results. Am...

Modern organizations face great challenges as they embrace innovation and integrate new tools and services. They begin to mature and move away from the complacency of maintaining traditional technologies and systems that only solve individual, siloed problems and work “well enough.” In order to build...

The post Gearing up for Digital Transformation appeared first on Aug. 25, 2016 12:15 PM EDT  Reads: 1,393