Java *

Zeppelin is a web-based notebook for data engineers that enables data-driven, interactive data analytics with Spark, Scala, and more.

The project recently reached version 0.9.0-preview2 and is being actively developed, but there are still many things to be implemented.

One such thing is an API for getting comprehensive information about what's going on inside the notebook. There is already an API that completely solves the problems of high-level notebook management, but it doesn’t help if you want to do anything more complex.

I offer a solution to one beautiful task — writing code that outputs its text is valid for interpreters and compilers of different languages and is correctly executed when reversing its sources.

Not so long ago I learned about code that can be both interpreted in PHP and compiled to Java: PhpJava.java. As it turned out, this idea is not new: code which is valid for several compilers or interpreters is called a polyglot. It is possible to write such code because of the peculiarities of processing strings and comments in different interpreters or compilers.

This is a post about first steps and first pitfalls in modernization of old enterprise application using "supersonic subatomic java" quarkus as it is positioned by RedHat.

Initial setup

In the end of 2019 I was invited to work in a project in our company, where an old monolithic application should be split into micro-services. Basic reasoning behind this decision was, that framework which is used in application is near to it's end-of-life. The application should be rewritten in any case. If it should be rewritten in any case, why not to split it into micro-services?

Since last 10 years, I was working mostly with java and we had in the project specialists with java knowledge, we have decided to give java-based frameworks a try for back-end functionality.
OK, let's use spring-cloud for that purpose, was our first thought. But then, we have had a look onto quarkus, which has been released in the end of 2019. We have decided to give it a try, keeping in mind building of native applications using GraalVM.

Native applications from our perspective could give us following benefits:

• shorten start time of container
• reduce resource consumption of container and application

We were aware about possible drawbacks of this solution:

• no experience in our team with quarkus framework
• significantly less amount of available feedback from community, since this is very young framework

Introduction

Hello Habr! My name is Nikita Letov. I am a tech lead of backend development in remote banking services for individuals (or retail department) of Rosbank. In this article I will describe what a point of entry to an app is, when it becomes vital, and how API Gateway can help you. We'll review a traditional blocking pattern based on Netflix Zuul 1.x gateway with all its problems of using, then reactive Spring Cloud Gateway and difficulties of moving to it. Finally, we'll compare these two approaches.

The point of this article is to explore Lambda functions, their dirrerences from regular functions and how they are implemented, based on C++, Python and Java programming languages.

Throughout this article I will be using godbolt.org to compile code and see machine code or byte code.

Polluting code with 'test-only' methods or access modifiers

This is a series of articles dedicated to the optimal choice between different systems on a real project or an architectural interview.

This topic seemed relevant to me because such tasks can be encountered both at work and at an interview for System Design Interview and you will have to choose between these two types of DBMS. I plunged into this issue and will tell you what and how. What is better in each case, what are the advantages and disadvantages of these systems and which one to choose, I will show with several examples at the end of the article.

SQL or NoSQL?

At first glance making REST and Apache Kafka compatible seems quite a challenge. However Innotech team nailed the task. Kirill Voronkin, Lead Developer at Innotech, shared the details on transforming unsynchronized queries into synchronized.

In previous post I've described an example of kogito-based microservice on quarkus in native mode, containing one embedded pmml model with decision tree. While it can be successfully used for prototyping purposes, in the real life microservice might contain several prediction models. From the first view I've got an impression, that inclusion of several models should be a trivial extension of the prototype with one model. We were completely wrong in our assumption, that's the reason, why I've decided to write this post. Another reason, is absence of guides, in which 2 (or more models) are put inside DMN diagrams in kogito framework.

Very often we've heard that some frameworks fit together so good, that they are considered as "match made in heaven". In this article I would like to share our experience regarding integration of those frameworks.

Privet, comrads!

In this article i’ll show how easy it is to setup Spring Java app with Kafka message brocker. We will use docker containers for kafka zookeeper/brocker apps and configure plaintext authorization for access from both local and external net.

Link to final project on github can be picked up at the end of the article.

Several years ago we had to solve how to enqueue events with an arbitrary delay, e.g. check a status of a payment 3 hours later, or send notification to a client in 45 minutes. At that point of time, we didn't find suitable libraries to accomplish this task, which didn't require us to spend time on configuration and maintenance. After analysing possible solutions we ended up building our own small library delayed queue in Java language on top of Redis storage engine. In this article I'll explain capabilities of this library, alternatives and problems we solved during creation process.

Who doesn’t know about Java today? You can hear its mention in every nook and corner of the world. A significant majority of IT companies provide Java-based applications, while businesses are still driven to secure java applications due to robustness and stringent security facilities. However, Java frameworks are a matter of chaos for a variety of business owners that want their application to be standout.

The fact is that there is no dearth of java frameworks that makes application development simple and efficient. However, a number of people have a query regarding the selection of java framework on the basis of features, ease-of-use, cost, and many more. Businesses hire programmers in India, though they stay confused on which platform they want their app to be created.

Working with SOAP often gets tricky, and dealing with WSDL might be a huge contribution to the complexity of this task. Really, it could be the least expected thing to face when you are into a modern & fancy language like for example, Scala, that is well known for its reactiveness and asynchronous way of dealing with requests. In fact, many of the software developers that have made their way into industry quite recently, might not even know about SOAP and WSDL protocols, and get quickly annoyed or even enraged when first trying to connect to such a legacy service. So, should we deprecate this altogether in favour of modern technology stack, or maybe there is a less painful solution?