Tag Archives: software quality

Microservices is not more than a specialized case of SOA

Over the last couple of years, there has been renewed energy in the subject of service oriented architectures. The invention of term ‘micro services’ has warranted a immense interest in the subject of service oriented architectures.

Despite the initial contention on the difference between SOA and the already mature Component Based Software Engineering (CBSE), there is consensus that SOA improves the key attributes of software such as agility, cost to market, flexibility, inter-operability and many others. A service in SOA is now understood as an autonomous software unit that can be used programmatically across the network. Services can interact regardless of the underlying technologies for as long they expose their interfaces for use by other entities.

The size of a service — how much functionality can be bundled into a single service unit is a issue of design left to programmers and software architects. Of course services are compositional – i.e. two or more services may be combined into a new service in its own right. Practice and programmatic recommendations suggest that a service should bundle a business functionality. And SOA in is traditional form has been largely conceived to be applicable at the business level.

Microservice advocate a new way of building systems with more fine grained service units. Simple low-level core functionality can now be exposed as services for use in building high-level systems. A micro service may be as large as a function in a functional language or method in Object oriented Language. Microservices should not be equated to functions or methods because a service is an architectural unit.

Whereas micro services raise the level of flexibility, they increase the number of ‘moving’ parts – each service is autonomous, deployeable in an independent process. This comes with well known challenges of distributed computing. Obviously we have come to learn that in software architecture there is need for trade-offs. It may be very hard to optimize both flexibility and reliability.

The level of granuality and new usage scenarios for microservices, require new support tools for designing, monitoring, provisioning, management of microservice based systems.

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Why Steal Software When There is Free Software?

Recently, one of the leading commercial software companies in the world has hired one of the leading advocates in town to crackdown individuals and organisations that are using software which is not licensed. That is people engaged in theft of software products — an act that is often called software piracy. In the past, there has been a feeling that most of the software companies are not local and therefore do not have local presence to detect and followup individuals using their products illegally. However, as of today, perhaps with the help of the credit crunch, even the largest companies are determined not to loose any revenue on products that represent their livelihood. Considering the price of these products and current economic downturn,   it may not be possible to pay for them and yet it is not possible to do without.

Actually, there is a better and smarter workaround. There are free software alternatives for all your needs ranging from simple document editing to advanced professional systems. Besides when you pay for the commercial products, you do not really own it, for instance it would be illegal to lend it to your friend or wife. Commercial software products are like buying a car that you cannot even give a driver to drive you or your spouse to pick your daughter from school.

Free software precisely means free of charge, that is software you can get at zero price. Moreover, free software gives the user freedom to use, to study and change it, and to redistribute it with or without changes. That is, you have the liberty to copy and redistribute in modified or unmodified form either without restriction, or with minimal restrictions to ensure that further recipients can also do similar things. Therefore those interested and with the technical know how can modify the software, add value or remove those unwanted features. Think about how often, you wanted to do something with a system, but it could not.

Let me first answer the question that might be developing in your mind – who owns the software if any, and how do they benefit? Precisely, a group of software engineers come together to build systems of interest. The answer is simple, the users do not directly pay for the software, but advertisers pay. In fact, to most commercial products there is a corresponding free software product. If your software needs are typing documents, spreadsheets, then OpenOffice is the answer to your needs. OpenOffice is free, powerful and provides an exceptional user experience. Of course you need an Operating System to start with. An Operating System controls and coordinates the activities of your hardware and other software on it. For free excellent Operating Systems, there are many choices from Linux based variants. My favorite is Ubuntu — “linux for humans”, spearheaded from South Africa. With Ubuntu, you do not worry about computer virus and comes with a collection of other software for all common activities. Be it music players, games, Internet software, e-mail software, they are all available on Ubuntu free of charge.

There is this old adage that free things are usually expensive. Free software is perhaps the first product am aware of to defy this adage, it is given completely free of change and performs better than the counterpart commercial software products. Take a case of Ubuntu, no virus is yet known to attack it. Indeed, the open source community has shown the way for many years: open peer review has proved to be an extremely effective way to detect design flaws, inefficiencies, and security holes.

Today, there are tens of millions of people around the world that use free software. Some free software products such as Apache Web Server command up to seventy five percent of the market. The question I have posed today, is then, why steal software when there is free software? Perhaps, one of the answers is that you are not aware of these free and excellent products. Maybe the one who exposed you to computing literacy had the same problem. There is always the first time, moreover, the free products provide similar or sometime better user experience because they are reviewed by many people. You have the freedom to lend or duplicate and use in anyway. Most important, if you have the competence, it is possible to personalise the software by removing or adding functionality to fit any taste.

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What About Sub-standard Software Systems

Like any incurable disease it (software) attracts more quarks, magicians and fortune tellers – -E.W. Dijkstra

In the past five years, I have come to think that it is valuable for the general public to know the distinction between a good computer system and a bad one, especially that the consequences affect even the innocent. Perhaps you have been to the bank and a teller casually announces that you can not withdraw or deposit money because the system is ‘down’, or you can not access your academic transcript because the system is ‘unavailable’. Maybe you have ever missed salary because of the computer system! Failure to withdraw your money may mean the landlord evicts you from the house or your son misses school. Failure to get the transcript may mean a missed life-time opportunity.

Such systems lead to wastage of millions of money, put lives at stake and businesses on the mercy of quarks. For government, the security of nation can be put at stake. The more computer systems fail, the more it becomes incurable because the general public has come to believe that it normal for systems to usually fail

A comparison with civil works

A comparison between the engineering of computer systems and civil engineering is informative. Unlike civil works, where the effects of a rudimentary engineering or lack of it are there to see through collapsing buildings, eroded fences and roadworks that are often fatal and lead to deaths, the effects of a rudimentary computer system are not readily visible. Mechanical engineers can get away with approximations for unknown or incalculable effects, substandard materials, and other surprises by building in safety margins. However, in software systems a single bit error can have disastrous consequences. Despite the the invisible nature of immeidate impacts of ill designed computer systems, the consequences  go beyond what most can predict and can be as fatal as a collapsing building with occupants.

Unlike civil works that may be faced with fake construction materials (such as cemment in Uganda), the key players in the construction of software systems are the programmers and those that buy the software. So the quality of the software is enitely in the hands of programmers.

Now warrant not guarantee -“as is”

 Interestingly, computer scientists mastered in advance, the art of hiding their incompetencies. They use fancy terms such as bugs to describe what ordinary means a malfunction. That is, a system that can not correctly do what it was intended to do. They do not even want to take responsibility of their own actions. Most software systems provide no guarantee or warrant for even the very mission the system is supposed to achieve.

The public has also accepted this situation and with not regret, it is not is common to hear  with a smile  that the computer system is not working, or the computer system is unavailable. Such lame explanations that have made system failure synonymous with the computing discipline are hurting. Such systems should not be casually accepted and need to be questioned for evidence of rigorous software engineering in the design and construction.

Good software is supposed to be reliable

Like any tool, a good software system is supposed to be reliable, that is safe to use by virtue of the fact that, when used, it acts as intended, or, more precisely, it reacts upon our inputs as intended. Even before subjecting a software system to a rigorous check for suitability of purpose, some indicator of incomplete and poor workmanship are usually there for even the computer illiterate to see. The first systems to be dismissed with contempt are those that fail due to any user inputs or limit existing good manual practices. That is, start by entering any data and good system should continue to behave normally. Bad systems will fail. Such systems are a clear manifestation of inept software engineering where the system is erected prematurely.

The buyer  at fault 

Executives, procurement officers should be aware that any programmer of some intelligence can cook up a computer system, the properties of which are utterly unattractive and unrelated to anything else. They need to be aware that the construction of computer systems is not a chaotic process with out systematic means to evaluate and sort them.

The executive managers with no formal training in software engineering approve these systems on the basis of their computer literacy normally in typing skills and email forwarding. Simple clicks and intelligent animations are usually enough to   append their signatures on products that are an art of ingenious and intelligent computer quarks.

Software production is a systematic process and quality can be assured

The most important aspect of a software-based system lie in the modeling and analysis of its interactions with external factors and overall mission assurance. Before purchasing or accepting to use a software system, it must be checked for for system-level information assurance issues. It must be checked for Possible fail-stop mechanisms and procedures, fallback, contingency solutions for both direct and secondary effects of failure modes. And Usage scenarios are frequently not a priori limited.

The regular failure and unavailability of computer systems has convinced the general public that it is normal for computer systems to fail. The proliferation of poor systems is a making of buyers who are easilty decieved by self made computer experts. As Edgar Dijkstra put it, Like any incurable disease it (software) attracts more quarks, magicians and fortune tellers

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