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Author Archives: gvaireth

From Java Source to Bare Metal, Part Three: The Networked Mountain

05 Jan

Episode 51

Hello traveler. Today we are continuing our journey through abstraction layers in a web application with all its foundations. Two episodes ago we started from Java code written by hand, followed by the web framework. One episode ago we went down into web servers, traveled through Java virtual machine to finally meet the container engine. Finally? Oh no, there is still long way before us.

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The cruise on the back of giant blue whale is over, and the Lonely Mountain is closer than ever. The Hobbit jumps out of the barrel and lands on solid ground somewhere in the city harbor. Meanwhile, the whale drifts away, unnoticed by busy workers. The hobbit leaves the dock and treads towards the building that dwarfs nearby ones with its size. The city hall.

On the Doorstep: The Operating system

In terms of the operating system, we are now crossing the border between the application and the kernel. We can say, that both sides were mediated by the container engine, which presents virtual kernel API to the application inside the container and maps all calls to the actual kernel API on which it resides. Java virtual machine and everything that’s sits on top of it, is now just another Read the rest of this entry »

 
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Posted by on January 5, 2017 in Technology

 

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From Java Source to Bare Metal, Part Two: The Desolation of Bytecode

29 Dec

Episode 50

In the previous episode, we started a journey through layers of abstraction of modern back-end web application. As a response to unexpected request, a Hobbit object is going to an adventure, and must travel safely across the technology stack. We seek an answer to the question what happens between Java code and the physical machine. Perhaps, even further.

Our Hobbit leaves the, yet familiar, plain of web framework and goes deep down under the Misty Server Mountains.

Riddles in the Dark: The Server

The code sits atop of web framework, and web framework sits atop of web server. That was mostly true until recently. Now, with Spring Boot, it is common that instead of deploying packed application to the server, there is a fat jar that contains embedded server inside an application. No configuration, no deployment, just running a single jar. Simple solution for simple problems, but of course it’s no silver bullet and might not fit everywhere. How does the server and the application fit together?

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There are different tiers of servers, as I wrote some time ago. The largest that we care about are application servers, like Read the rest of this entry »

 
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Posted by on December 29, 2016 in Technology

 

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From Java Source to Bare Metal, Part One: An Unexpected Request

22 Dec

Episode 49

Imagine you are developing a web application based on a typical modern technology stack. In essence, the goal is to create something that receives requests from the network, processes them, and responds to them with some kind of structured data. It can be a fancy HTML webpage to be displayed in client’s web browser or it can be a raw text object to be consumed by another application web API. Have you ever wondered what exactly is going on behind the scenes? What is happening between the moment when the code you wrote is executed and the moment when electrical impulses jumps the network cable sticking out of that metal box in the data center? Let me take you on the journey along numerous layers of abstraction in modern software stack that must be bypassed to make things happen.

There and Back Again: Abstractions

Programming is all about abstractions. We endlessly put one layer above the other in order to deal with tremendous complexity of software and hardware. Often, we ignore most of the layers to focus on solving the actual problem at hand. In principle, sending a JSON object over the network might seem like an easy task with modern tools and frameworks. You generate the project, tweak just a little bit here and there, write one method with few annotations and there you go, it works. But the engineering problem of making this possible in an easy, fast, secure, reliable, scalable and manageable way is gargantuan. Looking at the big picture, it’s probably an effort of hundreds of thousands of software developers, architects, electronic and electrical engineers, computer scientist and mathematicians, spanned over several decades of work. All that, to let you do the job in a single pomodoro.

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Of course, to develop decent software, you don’t necessary have to understand exactly how all this works, it’s probably not even possible for a single human being to grasp all that in every detail. I believe however Read the rest of this entry »

 
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Posted by on December 22, 2016 in Spring, Technology

 

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Software Talks Rzeszów Dec 2016 and banking apps security

15 Dec

Episode 48

Software Talks is a recurring event organized by PGS Software, consisting of tech talks, beer, pizza and a lot of fun. Some time ago I wrote about the two September editions in Wrocław and Gdańsk, in which I took part as a speaker. On December 8th there was another event, this time in Rzeszów, a city located in south-eastern Poland. I was a speaker for the third time in a row, but for the first time with my colleague Tomasz Zieliński, who recently made a lot of noise in Polish banking environment, preparing a report, which exposed several critical security issues and other major problems in their mobile banking applications. If you read my article about working for different types of companies, you might have noticed that I’m not a big fan of banks’ approach to software development, so I’m going to elaborate on Tomasz findings without mercy.

Background

Last time on Software Talks I spoke with Piotr Konieczny, Polish security expert. This time there was an idea to focus more on Java / software development topics, so I was on a mission to find a second Java speaker. I found one, but at the last moment some issues appeared and he couldn’t make it, so his place was taken by Tomasz, who is actually our Android expert.

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It was kind of a busy week for me, as I was three days in Berlin with our client, arrived in Wrocław on Wednesday evening, and an hour later I was in a car with Read the rest of this entry »

 
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Posted by on December 15, 2016 in News, Technology

 

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API management tools

08 Dec

Episode 47

Long time ago, the Internet was full of proud and secluded applications, that relied on themselves to provide service. However, services were becoming more and more complicated, also technologies and protocols for connecting with other applications became more standardized. It became obvious that collaboration and specialization is required to survive. Applications thus started to be more specialized, talk to each other much more, and the level of digital interconnection skyrocketed. Along with that, did the market of solutions for managing web APIs.

Do I need API?

Most likely you do. Imagine a big corporation that is building HR system. They want the module related to business travel for planning and reporting. Is there a point in writing everything from scratch? If you plan travel, let’s ask someone who is already good at it. If you want to buy a ticket from A to B, there are companies that provide travel meta search service, both via website and API.

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Those companies need data, so they ask someone who possess it – bus and train operators, airlines, car rentals and perhaps other travel meta search companies. Maybe, when planning travel, especially the end points, we might want to specify an address. How do we know that address is correct? We should ask someone who Read the rest of this entry »

 
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Posted by on December 8, 2016 in API, Technology

 

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FutureDevDay Gliwice 2016

01 Dec

Episode 46

On November 25th I attended a small conference organized by Future Processing in Gliwice. We get there, me and my two friends, in less than two hours of driving from Wrocław. The conference was held in a really lovely building within a complex of Upper Silesian Agency for Entrepreneurship and Development. Few hundred developers gathered for a single track composed of 11 talks 25 minutes each and finally a special guest talking for an hour.

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At the end, there was an after party in a nearby bar (called “progress bar”, how cute!) with three discussion panels, food and beer.

Talks

Talks were grouped thematically into categories composed of two or three each. First were architectural ones, then frontend, cloud and finally big data. I decided to write more about few sessions I liked the most and to take liberty at titles translation, if required. Let’s start with Read the rest of this entry »

 
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Posted by on December 1, 2016 in News, Technology

 

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Craftsmanship, Science, Engineering and Art

24 Nov

Episode 45

As you might have noticed, if you read my blog for some time, I like the parallel between modern software development and medieval craftsmanship. I used it recently when talking about seniority in programming along with other measures. I did reviews of two books on the topic some time ago here and there, but now I would like to devote entire article just to that. To be more specific, I would like to talk about the essence of modern software development and why it’s important to understand this.

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It will be a bit of a historic tour, we will start from formal beginnings of computer science, and its relation to early programmers. Then we will take a look at spectacular rise and fall of a new engineering discipline. Next comes the art, both as creative endeavor and as philosophy, especially in traditional martial arts. Finally we will arrive at craftsmanship, and Read the rest of this entry »

 
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Posted by on November 24, 2016 in Technology

 

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Seniority in Programming: Part Two

17 Nov

Episode 44

Last week, in part one of this article, I was pondering about levels of competence in general and in software development. I looked at mainstream naming schemas, recalled metaphor to medieval craftsmanship, described ranks in Japanese martial arts, presented SFIA skill framework and finally ability’s dots in role-playing game system. Now, let’s try to do something with it. How much levels do we actually want? Well, let’s have four.

junior.jpgApprentice

  • HR would call it junior developer
  • Sensei would call it 5th to 4rd kyu
  • SFIA would call it level 2 to 3, the one who assists and applies
  • VtM handbook would call it 2 dots, the practitioner

We all have to start somewhere. I’m assuming that this is how we should call a person that begins professional career in software development, and has knowledge usually associated with at least bachelor degree in computer science or closely related field. Apprentice has some theoretical grasp and academic experience, but not much, if any, with commercial projects. Why skip 1st level of SFIA and 1st dot in VtM handbook? Because to be employed as junior developer, you have to know quite a lot. It’s not like random person from the street can get the job and do well after some on-site training. It’s not a damn factory. One need to understand some basics of computer science, and be able to code something. I’m not saying academic degree is a must, because many prominent programmers don’t have one, but some knowledge in the field is a Read the rest of this entry »

 
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Posted by on November 17, 2016 in Misc, Recruitment

 

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Seniority in Programming: Part One

10 Nov

Episode 43

While browsing job offers in software development, you can often encounter words like “junior”, “middle”, “regular”, “senior”, “lead” or “principal”. What do they actually mean? Correct answer, as usual, is: it depends. The idea of job grades, pay grades, tiers or seniority levels seems to be quite subjective, depending on job market situation, country, company, technology and if HR people have a good day or not. Let’s explore the subject and try to find some answers. I will reach for some metaphors and analogies to help with this endeavor.

Assuming that software development is a single monolithic skill, which is a thick approximation, we can ask an essential question – how to grade one’s skill. There are quite a few approaches, let’s dive into some of them.

Pay grade

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Typical corporate breakdown you can find out there, is “junior” / “middle” / “senior”. Many companies add another level above, usually called “lead”, “principal” or “staff” and sometimes a level below, like “intern”. One corporation had once a Read the rest of this entry »

 
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Posted by on November 10, 2016 in Recruitment, Technology

 

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A Brief History of Java and Vampires

31 Oct

Episode 42

As you may have noticed, my focus in this blog is shifting away from Java itself to more general topics related to software development, despite having “Java” word in the blog name. Well, two months ago I even changed the name from JEE to Java, because I felt JEE was too specific. Let’s get back to roots and explore a bit of history of the Java platform.

As a Halloween guest stars, the article will feature the story of creatures of the darkness, as portrayed in role-playing game Vampire the Masquerade. Lets look at their hierarchy, from oldest to youngest.

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Said to be vampires of incalculable power, each of whom survived the Biblical Deluge. Considered to be the founders of the thirteen clans and members of the third generation.

1990 – In December, Patrick Naughton starts the Stealth Project which will later become what we now know as Java. The aim is to create a platform that will speed up software development and render C++ language and its tools obsolete.

1991 – The Green Project is the new name of the platform, James Gosling and Mike Sheridan are also on the team, which now consist of 13 people in total. Gosling starts the work on the core platform language, then called the Oak.

1992 – First internal demonstration of the platform. Duke, the future Java mascot makes first appearance. Read the rest of this entry »

 
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Posted by on October 31, 2016 in Misc, Technology

 

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