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79 items found: Search results for "java 8" in all categories x

Many improvements in Java 8 API for Akka

June 24, 2016 | Software Consultancy

Many improvements in Java 8 API for Akka

Akka has been designed with a Java API from the very first version. Though widely adopted, as a Java developer I think Akka has been mainly a Scala thing… until recently. Things are changing and Akka is moving to a proper Java 8 support.

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Lambda memoization in Java 8

August 19, 2015 | Software Consultancy

Lambda memoization in Java 8

Memoization is a technique whereby we trade memory for execution speed. Suppose you have a function which

  • Is costly to execute.
  • Always returns the same output for the same input.
  • May be called many times with the same input.

In this scenario, it may make sense to “remember” the output returned for each distinct input in a hash map, and replace function execution with a lookup in the hash map.

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New Tricks With Dynamic Proxies In Java 8 (part 3)

August 18, 2015 | Software Consultancy

New Tricks With Dynamic Proxies In Java 8 (part 3)

In this post, the last in the New Tricks With Dynamic Proxies series (see part 1 and part 2), I’m going to look at using dynamic proxies to create bean-like value objects to represent records. The basic idea here is to have some untyped storage for a collection of property values, such as an array of Objects, and a typed wrapper around that storage which provides a convenient and type-safe access mechanism. A dynamic proxy is used to convert calls on getter and setter methods in the wrapper interface into calls which read and write values in the store.

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New Tricks with Dynamic Proxies in Java 8 (part 2)

July 14, 2015 | Software Consultancy

New Tricks with Dynamic Proxies in Java 8 (part 2)

Building simple proxies

In the previous post I introduced Java dynamic proxies, and sketched out a way they could be used in testing to simplify the generation of custom Hamcrest matchers. In this post, I’m going to dive into some techniques for implementing proxies in Java 8. We’ll start with a simple case, and build up towards something more complex and full-featured.

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New Tricks with Dynamic Proxies in Java 8 (part 1)

July 13, 2015 | Software Consultancy

New Tricks with Dynamic Proxies in Java 8 (part 1)

Why Use Dynamic Proxies?

Dynamic proxies have been a feature of Java since version 1.3. They were widely used in J2EE for remoting. Given an abstract interface, and a concrete implementation of that interface, a call to some method on the interface can be made “remote” (i.e. cross-JVM) by creating two additional classes. The first, a “marshalling” implementation of the interface, captures the details of the call in the source JVM and serializes them over the network. The second, an “unmarshalling” endpoint, receives the serialized call details and dispatches the call to an instance of the concrete class on the target JVM.

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Traits with Java 8 Default Methods

January 30, 2015 | Software Consultancy

Traits with Java 8 Default Methods

When I first started programming in Scala a few years ago, Traits was the language feature I was most excited about. Indeed, Traits give you the ability to compose and share behaviour in a clean and reusable way. In Java, we tend deal with the same concerns by grouping crosscutting behaviour in abstract base classes that are subsequently extended every time we need to access shared behaviour in part or in total.

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Lunch & Learn: GraalVM and Java Native Image

May 12, 2022 | Microservices

Lunch & Learn: GraalVM and Java Native Image

Combining Native image with Spring Boot and Micronaut GraalVM makes for a high-performance runtime that can significantly improve application performance and efficiency, making it ideal for microservices. Native images enable Java applications to be compiled ahead of time, resulting in smaller, faster Java microservices.

In this talk, Guy Coleman will demonstrate a hello world web service using both Spring Boot and Micronaut as they both support native images.

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[Past event] …Think Software 2018, London

Join us at …think software 2018! Take one afternoon to learn about some of the most important topics of the day, hear from outstanding speakers all with hard-won experience delivering projects.

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[Past event] Devoxx UK 2018

Join us for Devoxx UK 2018! We are excited to announce that we are sponsoring and speaking at Devoxx UK 2018. Devoxx is a conference by developers, for developers. Conference Tracks include: Cloud, Containers & Infratructure Big Data & AI Architecture Server Side Java Modern Web Programming Languages Security and much more… Multi Env Deploys […]

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From Java to Go, and Back Again

October 13, 2016 | Data Analysis

From Java to Go, and Back Again

In Lisp, you don’t just write your program down toward the language, you also build the language up toward your program. As you’re writing a program you may think “I wish Lisp had such-and-such an operator.” So you go and write it. Afterward you realize that using the new operator would simplify the design of another part of the program, and so on. Language and program evolve together…In the end your program will look as if the language had been designed for it. And when language and program fit one another well, you end up with code which is clear, small, and efficient – Paul Graham, Programming Bottom-Up

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[Past event] JavaOne 2016

Join Daniel at JavaOne 2016 on the 18th of September!   Java, the Cloud, Containers: Migrating Without the Tiers (or Tears) [CON3601]   Everyone is talking about building “cloud native” Java applications—and taking advantage of microservice architecture, containers, and orchestration/PaaS platforms—but there is, surprisingly little discussion of migrating existing legacy (moneymaking) applications. This session aims to […]

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[Past event] Java Community Meetup

Come along and see the Consultant’s Guide to Consulting Craftily in DevOps by OpenCredos’ Daniel Bryant. Have the chance to learn how the Crafty Consultant makes his money by consulting craftily in DevOp!

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JavaOne: Debugging Java Applications Running in Docker

November 3, 2015 | Software Consultancy

JavaOne: Debugging Java Applications Running in Docker

My JavaOne experience was rather busy this year, what with three talks presented in a single day! The first of these talks “Debugging Java Apps in Containers: No Heavy Welding Gear Required” was delivered with my regular co-presenter Steve Poole, from IBM, and we shared our combined experiences of working with Java and Docker over the past year.

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JavaOne: Building a Microservice Development Ecosystem (Video)

October 31, 2015 | Microservices

JavaOne: Building a Microservice Development Ecosystem (Video)

Microservices: Some Assembly Required

Over the past few weeks I’ve been writing an OpenCredo blog series on the topic of “Building a Microservice Development Ecosystem”, but my JavaOne talk of the same title crept up on me before I managed to finish the remaining posts. I’m still planning to finish the full blog series, but in the meantime I thought it would be beneficial to share the video and slides associated with the talk, alongside some of my related thinking. I’ve been fortunate to work on several interesting microservice projects at OpenCredo, and we’re always keen to share our knowledge or offer advice, and so please do get in touch if we can help you or your organisation.

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JavaOne: Thinking Fast and Slow with Software Development

October 30, 2015 | Software Consultancy

JavaOne: Thinking Fast and Slow with Software Development

Think More About Thinking…

Having completed my marathon 3-talks-in-one-day at JavaOne on Wednesday, I’m now in a position to share all of the slides and supporting material. First up is the content associated with my “Thinking Fast and Slow with Software Development” talk. I’ve already blogged about an earlier version of this presentation on the OpenCredo blog, and so won’t go into more detail here. However, I will include the video recording (thanks to the JavaOne team for this!), the latest version of the slides, and a much requested reading list!

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Join OpenCredo at JavaOne in San Francisco

October 18, 2015 | DevOps, Microservices

Join OpenCredo at JavaOne in San Francisco

Microservices, Debugging Containers and Software Development Methodologies

Once again I’m privileged to be speaking at the premier Java conference, JavaOne in San Francisco. This year I will be presenting (at least) three conferences sessions: “Building a Microservice Ecosystem”, “Debugging Java Apps in Containers” and “Thinking, Fast and Slow, with Software Development”. I say ‘at least’ three talks as I usually get press-ganged volunteered into helping out at other talks and BoF sessions, but this is simply a sign of the great community spirit and a large group of friends involved with this conference!

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48 hours – The Pursuit of Proper Performance

February 13, 2012 | Software Consultancy

48 hours – The Pursuit of Proper Performance

Recently we were approached by a client to do some performance testing of the web application they had written. The budget allowed two days for this task. Ok. No problem. Yes, we can. Naturally I had one or another question though…

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[Past event] Applied Data Engineering Meetup #5

Join us for Applied Data Engineering Meet Up #5 with Ben Evans, Co-Founder of jClarity, who will be talking some of their work with Hazelcast Jet and Spark.

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Data Analytics using Cassandra and Spark

March 23, 2017 | Cassandra, Data Analysis, Data Engineering

Data Analytics using Cassandra and Spark

In recent years, Cassandra has become one of the most widely used NoSQL databases: many of our clients use Cassandra for a variety of different purposes. This is no accident as it is a great datastore with nice scalability and performance characteristics.

However, adopting Cassandra as a single, one size fits all database has several downsides. The partitioned/distributed data storage model makes it difficult (and often very inefficient) to do certain types of queries or data analytics that are much more straightforward in a relational database.

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Event Replaying with Hazelcast Jet

February 13, 2017 | Data Engineering

Event Replaying with Hazelcast Jet

One of the stated intentions behind the design of Java 8’s Streams API was to take better advantage of the multi-core processing power of modern computers. Operations that could be performed on a single, linear stream of values could also be run in parallel by splitting that stream into multiple sub-streams, and combining the results from processing each sub-stream as they became available.

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Reactive event processing with Reactor Core: a first look

January 26, 2017 | Data Engineering

Reactive event processing with Reactor Core: a first look

Suppose you are given the task of writing code that fulfils the following contract:

  • You will be given a promise that, at some point in the future, some data – a series of values – will become available.
  • In return, you will supply a promise that, at some point in the future, some data representing the results of processing that data will become available.
  • There may be more values to process than you can fit in memory, or even an infinite series of values.
  • You are allowed to specify what will be done with each individual value, as and when it becomes available; this includes discarding some values.
  • Whenever you want to use some external service to do something with a value, that service can only return you a promise that, at some point in the future, some data representing the result of processing that value will become available.

 

This blog is written exclusively by the OpenCredo team. We do not accept external contributions.

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The Destructor Pattern

June 3, 2016 | Software Consultancy

The Destructor Pattern

Complexity warning

In this post, I’m going to take something extremely simple, unfold it into something disconcertingly complex, and then fold it back into something relatively simple again. The exercise isn’t entirely empty: in the process, we’ll derive a more powerful (because more generic) version of the extremely simple thing we started with. I’m describing the overall shape of the journey now, because programmers who don’t love complexity for its own sake often find the initial “unfolding” stage objectionable, and then have trouble regarding the eventual increase in fanciness as worth the struggle.

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Complex Kotlin

May 25, 2016 | Software Consultancy

Complex Kotlin

In this post I’m going to demonstrate the implementation of Complex, a Kotlin class handling complex numbers, which uses operator overloading to provide the usual arithmetic operations for those numbers. In the process, I’ll also demonstrate a Kotlin pattern which I call “complicit conversion”, and show how to implement complicit conversion between two types: Double and Complex.

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The Concursus Programming Model: Kotlin

April 29, 2016 | Software Consultancy

The Concursus Programming Model: Kotlin

In this post, I’ll demonstrate an alternative API which uses some of the advanced language features of the new Kotlin language from Jetbrains. As Kotlin is a JVM-based language, it interoperates seamlessly with Concursus’s Java 8 classes; however, it also offers powerful ways to extend their functionality.

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Kotlin: a new JVM language you should try

March 3, 2016 | Software Consultancy

Kotlin: a new JVM language you should try

JetBrains (the people behind IntelliJ IDEA) have recently announced  the first RC for version 1.0 of Kotlin, a new programming language for the JVM. I say ‘new’, but Kotlin has been in the making for a few years now, and has been used by JetBrains to develop several of their products, including Intellij IDEA. The company open-sourced Kotlin in 2011, and have worked with the community since then to make the language what it is today.

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July 28, 2015 | Microservices

Documenting REST APIs – a tooling review

Recently I co-presented a talk at Goto Amsterdam on lessons learnt whilst developing with a Microservices architecture; one being the importance of defining and documenting your API contracts as early as possible in the development cycle. During the talk I mentioned a few API documentation tools that I’d used and, based on feedback and questions from attendees, I realised that this topic merited a blog post. So, the purpose of this is to introduce 5 tools which help with designing, testing and documenting APIs.

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DZone Repost: Testing Serverless Functions

February 11, 2022 | AWS, Cloud, GCP, Kubernetes, Microservices, Open Source, Software Consultancy

DZone Repost: Testing Serverless Functions

Serverless functions are easy to install and upload, but we can’t ignore the basics. This article looks at different strategies related to testing serverless functions.

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WebAssembly – Where is it going?

December 11, 2020 | Cloud, Cloud Native, Kubernetes, Microservices

WebAssembly – Where is it going?

“WebAssembly is a safe, portable, low-level code format designed for efficient execution and compact representation.” – W3C

In this blog, I’ll cover the different applications of Wasm and WASI, some of the projects that are making headway, and the implications for modern architectures and distributed systems.

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Decision time with AWS Keyspaces

September 22, 2020 | AWS, Blog, Cassandra, Cloud, DevOps, Open Source

Decision time with AWS Keyspaces

With the upcoming Cassandra 4.0 release, there is a lot to look forward to. Most excitingly, and following a refreshing realignment of the Open Source community around Cassandra, the next release promises to focus on fundamentals: stability, repair, observability, performance and scaling.

We must set this against the fact that Cassandra ranks pretty highly in the Stack Overflow most dreaded databases list and the reality that Cassandra is expensive to configure, operate and maintain. Finding people who have the prerequisite skills to do so is challenging.

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Kafka Connect – Source Connectors: A detailed guide to connecting to what you love.

July 30, 2019 | Blog, Kafka

Kafka Connect – Source Connectors: A detailed guide to connecting to what you love.

Writing your own Kafka source connectors with Kafka Connect. In this blog, Rufus takes you on a code walk, through the Gold Verified Venafi Connector while pointing out the common pitfalls

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Securing Kafka using Vault PKI

February 20, 2019 | DevOps, Hashicorp, Kafka, Open Source

Securing Kafka using Vault PKI

Creating and managing a Public Key Infrastructure (PKI) could be a very straightforward task if you use appropriate tools. In this blog post, I’ll cover the steps to easily set up a PKI with Vault from HashiCorp, and use it to secure a Kafka Cluster.

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[Past event] Hashicorp User Group #24

Thanks to our hosts Mintel, the HashiCorp User Group is back on the 14th of August with speakers from applyingAgile and Grafana labs.

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Self-testing infrastructure-as-code

May 31, 2018 | DevOps

Self-testing infrastructure-as-code

As traditional operations has embraced the concept of code, it has benefited from ideas already prevalent in developer circles such as version control. Version control brings the benefit that not only can you see what the infrastructure was, but you can also get reviews of changes by your peers before the change is made live; known to most developers as Pull Request (PR) reviews.

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[Past event] Muon User Group #1

We are excited to be hosting the first Muon User Group at our London office for an Intro to Muon – How to build Polyglot Message and Event Microservices!

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Riak, the Dynamo paper and life beyond Basho

August 8, 2017 | Cassandra

Riak, the Dynamo paper and life beyond Basho

Recently, the sad news has emerged that Basho, which developed the Riak distributed database, has gone into receivership. This would appear to present a problem for those who have adopted the commercial version of the Riak database (Riak KV) supported by Basho.

 

This blog is written exclusively by the OpenCredo team. We do not accept external contributions.

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Testing a Spark Application

May 9, 2017 | Cassandra

Testing a Spark Application

Data analytics isn’t a field commonly associated with testing, but there’s no reason we can’t treat it like any other application. Data analytics services are often deployed in production, and production services should be properly tested. This post covers some basic approaches for the testing of Cassandra/Spark code. There will be some code examples, but the focus is on how to structure your code to ensure it is testable!

 

This blog is written exclusively by the OpenCredo team. We do not accept external contributions.

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Deploy Spark with an Apache Cassandra cluster

May 2, 2017 | Cassandra, Data Engineering

Deploy Spark with an Apache Cassandra cluster

My recent blogpost I explored a few cases where using Cassandra and Spark together can be useful. My focus was on the functional behaviour of such a stack and what you need to do as a developer to interact with it. However, it did not describe any details about the infrastructure setup that is capable of running such Spark code or any deployment considerations. In this post, I will explore this in more detail and show some practical advice in how to deploy Spark and Apache Cassandra.

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Automating Your Security Acceptance Tests

March 23, 2017 | Data Engineering, Machine Learning

Automating Your Security Acceptance Tests

On previous blog posts we have provided examples of different types of acceptance tests coverage, UI, API and Performance. One area where automation is often lacking is around validating the security of the application under test. This has been discussed in the post on non functional testing You Are Ignoring Non-functional Testing. With this post we will enhance the automation framework to quickly check for some common security flaws.

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Google Cloud Spanner: our first impressions

March 7, 2017 | Data Analysis, GCP

Google Cloud Spanner: our first impressions

Google has recently made its internal Spanner database available to the wider public, as a hosted solution on Google Cloud. This is a distributed relational/transactional database used inside for various Google projects (including F1, the advertising backend), promising high throughput, low latency and 99.999% availability. As such it is an interesting alternative to many open source or other hosted solutions. This whitepaper gives a good theoretical introduction into Spanner.

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What I Don’t Like About Error Handling in Go, and How to Work Around It

January 23, 2017 | Data Analysis

What I Don’t Like About Error Handling in Go, and How to Work Around It

More often than not, people who write Go have some sort of opinion on its error handling model. Depending on your experience with other languages, you may be used to different approaches. That’s why I’ve decided to write this article, as despite being relatively opinionated, I think drawing on my experiences can be useful in the debate. The main issues I wanted to cover are that it is difficult to force good error handling practice, that errors don’t have stack traces, and that error handling itself is too verbose.

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[Past event] London Mesos User Group #13

The London Mesos User Group is back for its monthly meetup on October the 20th! We are excited to announce that a couple of MesosCon EU speakers have kindly agreed to join us and would like thank GoCardless who are providing us with a venue and JFrog for very kindly supplying the beer and pizza. […]

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Common Problems with Cassandra Tombstones

September 27, 2016 | Cassandra, Data Engineering

Common Problems with Cassandra Tombstones

If there is one thing to understand about Cassandra, it is the fact that it is optimised for writes. In Cassandra everything is a write including logical deletion of data which results in tombstones – special deletion records. We have noticed that lack of understanding of tombstones is often the root cause of production issues our clients experience with Cassandra. We have decided to share a compilation of the most common problems with Cassandra tombstones and some practical advice on solving them.

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[Past event] VJUG24 2016

VJUG24 is the first 24hour virtual Java conference in the world! Find out more and join Daniel Bryant for his talk “The Seven (More) Deadly Sins of Microservices.”

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Simulating GitHub OAuth2 Login for Tests with JUnit, Webdriver & Hoverfly: Record, Sanitise, Playback and Assert

September 21, 2016 | DevOps

Simulating GitHub OAuth2 Login for Tests with JUnit, Webdriver & Hoverfly: Record, Sanitise, Playback and Assert

Sometimes, it can be difficult to write automated tests for parts of your application due to complexities introduced by an external dependency. It may be flaky or have some sort of rate limiting, or require sensitive information which we don’t want to expose outside of our production environment. To get around this, teams might take the approach of manually stubbing the service or using mocks – but the former is tedious and error prone, whereas the latter doesn’t test collaboration at all.

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Fulfilling the promise of Apache Cassandra performance

August 24, 2016 | Cassandra

Fulfilling the promise of Apache Cassandra performance

At OpenCredo we are seeing an increase in adoption of Apache Cassandra as a leading NoSQL database for managing large data volumes, but we have also seen many clients experiencing difficulty converting their high expectations into operational Cassandra performance. Here we present a high-level technical overview of the major strengths and limitations of Cassandra that we have observed over the last few years while helping our clients resolve the real-world issues that they have experienced.

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The Concursus Programming Model: Under the Hood

April 29, 2016 | Software Consultancy

The Concursus Programming Model: Under the Hood

In the previous two posts (part 1, and part 2), we looked at how Concursus uses method mapping to generate events from method calls on proxies, and to dispatch events to matching methods on event handlers and state class instances. This approach provides a concise, convenient client API to the Concursus event system; however the core of the system defines events and event-handling mechanisms without reference to any of the reflection-based machinery used to implement this API. It is perfectly possible (if comparatively cumbersome) to use a Concursus event store to read and write events without using reflection. In this post I’ll show how this is done, continuing with the “lightbulb” example introduced previously.

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The Concursus Programming Model: State

April 28, 2016 | Software Consultancy

The Concursus Programming Model: State

In a conventional RDBMS-with-ORM system, we are used to thinking of domain objects as mapped to rows in database tables, and of the database as a repository where the current state of every object exists simultaneously, so that what we get when we query for an object is the state that object was in at the time the query was issued. To perform an update, we can start a transaction, retrieve the current state of the object, modify it, save it back again and commit. Transactions move the global state of the system from one consistent state to another, so that the database transaction log represents a single, linear history of updates. We are therefore able to have a very stable, intuitive sense of what it means to talk about the “current state” of any domain object.

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The Concursus Programming Model: Events

April 27, 2016 | Software Consultancy

The Concursus Programming Model: Events

Concursus is an open source Java 8 framework for building distributed systems using CQRS and event sourcing patterns. One of its major differences from other such frameworks (such as Jdon, Axon and ES4J) is that it eschews a programming model where each event type is represented by a separate Java class, instead mapping event types to methods on interfaces.

 

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Test Automation Concepts – Automated email testing

March 29, 2016 | Software Consultancy

Test Automation Concepts – Automated email testing

Raise your test coverage with automated email testing

Acceptance test suites generally are used for UI and API testing, and we have covered both these approaches in our Test Automation Quickstart project. However, an application may, for example, send registration or expiration warning emails. Often, tests related to this are left to manual testing, instead of putting them into an automated test suite.

However, there’s no need to check emails manually: it suffers from all the same problems as other manual testing. It’s slow, expensive, and inconsistent. There are many libraries available to interact with email through code – this post will focus on how to use them within an automated test suite.

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Easy API Simulation with Hoverfly JUnit Rule

March 17, 2016 | Software Consultancy

Easy API Simulation with Hoverfly JUnit Rule

In order to be able to regularly release an application, your automated tests must be set up to give you fast and reliable feedback loop. If bugs are only found during a long and expensive multi-service or end-to-end test run, it can be a hinderance to fast delivery. Unfortunately I have often seen this problem in development environments: a huge suite of clunky, flaky and slow end-to-end tests which test the full functionality of the application as opposed to being more lightweight and reflecting basic user journeys. This produces the “ice cream cone” anti-pattern of test coverage, where unit tests aren’t providing the kind of coverage and feedback they need to.

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Test Automation Concepts – Parallel test execution

March 14, 2016 | Software Consultancy

Test Automation Concepts – Parallel test execution

Test automation provides fast feedback on regressions. In order to achieve this tests need to execute quickly, something which becomes more of a problem as test suites grow. This is especially true of tests which exercise a user interface where the interaction with the system is slower.

A good way to address this is to have your tests execute in parallel rather than consecutively. Given sufficient resources this allows your execution time to remain low almost indefinitely as more scenarios are added to the suite.

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React/Redux boilerplate

March 3, 2016 | Software Consultancy

React/Redux boilerplate

In this post, I’ll be sharing some React/Redux boilerplate code that Vince Martinez and I have been developing recently. It’s primarily aimed at developers who are familiar with the React ecosystem, so if you are new to React and/or Redux, you might like to have a look at Getting Started with React and Getting Started with Redux.

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Hazelcast and Spring-managed Transactions: A Sample Integration

January 26, 2016 | Data Engineering

Hazelcast and Spring-managed Transactions: A Sample Integration

In this second post about Hazelcast and Spring, I’m integrating Hazelcast and Spring-managed transaction for a specific use case: A transactional Queue. More specifically, I want to make the message polling, of my sample chat application, transactional.

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Facebook’s React, and the Signal:Noise Ratio

January 15, 2016 | Software Consultancy

Facebook’s React, and the Signal:Noise Ratio

So, you’ve started to hear a lot about React, the Javascript library developed by Facebook, but is it something you need to investigate? It’s time to distil the signal from the noise, position React amongst its rivals, and provide an indication of where it currently would – and would not – be a suitable fit.

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The Seven Deadly Sins of Microservices (Redux)

January 8, 2016 | Microservices

The Seven Deadly Sins of Microservices (Redux)

Many of our clients are in the process of investigating or implementing ‘microservices’, and a popular question we often get asked is “what’s the most common mistake you see when moving towards a microservice architecture?”. We’ve seen plenty of good things with this architectural pattern, but we have also seen a few recurring issues and anti-patterns, which I’m keen to share here.

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OpenCredo is now an Amazon Web Services APN Consulting Partner
(Spring) Booting Hazelcast

December 1, 2015 | Software Consultancy

(Spring) Booting Hazelcast

This post introduce some of the basic features of Hazelcast, some of its limitations, how to embed it in a Spring Boot application and write integration testings. This post is intended to be the first of a series about Hazelcast and its integration with Spring (Boot). Let’s start from the basics.

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RAML 1.0 promotes reusability and standardisation

November 25, 2015 | Microservices

RAML 1.0 promotes reusability and standardisation

In May a 1.0 release of RAML (RESTful API Markup Language) has been announced delivering a few much welcome additions in the RAML 1.0 specification. This major release marks an important milestone in the evolution of RAML and indicates the team behind the specification is confident this release delivers the comprehensive set of tools for developing RESTful APIs. I’ve been using RAML 0.8 for several months now and have enjoyed the simplicity and productivity it offers for designing and documenting APIs. I must say I’m quite pleased with the changes introduced in the new release and would like to review those I consider particularly useful.

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Reusing ansible roles with private git repos and dependency management

November 4, 2015 | Software Consultancy

Reusing ansible roles with private git repos and dependency management

Writing reusable roles for Ansible is not an easy task but one that’s worth doing. This post should walk you through the basics of writing reusable roles with dependencies backed by public and private git repositories.

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Implementing HAL hypermedia REST API using Spring HATEOAS

November 1, 2015 | Microservices

Implementing HAL hypermedia REST API using Spring HATEOAS

To use or not to use hypermedia (HATEOAS) in a REST API, to attain the Level 3 of the famous Richardson Maturity Model. This is one of the most discussed subjects about API design.
The many objections make sense (“Why I hate HATEOAS“, “More objections to HATEOAS“…)
. The goal of having fully dynamic, auto-discovering clients is still unrealistic (…waiting for AI client libraries).

However, there are good examples of successful HATEOAS API. Among them, PayPal.

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The curse of correlation

October 7, 2015 | Software Consultancy

The curse of correlation

How correlated estimates make prediction in IT hard.

It’s well known that predicting how long a project/task will take in IT is hard. In this post I’ll address one aspect of this (correlation) and ask what insights a data science perspective can give us about how correlations can make prediction difficult. I’ll explain the problems that correlation poses, give some practical advice for teams & project managers and investigate possible innovations to tooling that might improve matters.

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Introduction to Akka Streams – Getting started

October 1, 2015 | Data Engineering

Introduction to Akka Streams – Getting started

Going reactive

Akka Streams, the new experimental module under Akka project has been finally released in July after some months of development and several milestone and RC versions. In this series I hope to gently introduce concepts from the library and demonstrate how it can be used to address real-life stream processing challenges.

Akka Streams is an implementation of the Reactive Streams specification on top of Akka toolkit that uses actor based concurrency model. Reactive Streams specification has been created by the number of companies interested in asynchronous, non-blocking, event based data processing that can span across system boundaries and technology stacks.

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Microservice Platforms: Some Assembly [Still] Required. Part Two

September 20, 2015 | Microservices

Microservice Platforms: Some Assembly [Still] Required. Part Two

Working Locally with Microservices

Over the past five years I have worked within several projects that used a ‘microservice’-based architecture, and one constant issue I have encountered is the absence of standardised patterns for local development and ‘off the shelf’ development tooling that support this. When working with monoliths we have become quite adept at streamlining the development, build, test and deploy cycles. Development tooling to help with these processes is also readily available (and often integrated with our IDEs). For example, many platforms provide ‘hot reloading’ for viewing the effects of code changes in near-real time, automated execution of tests, regular local feedback from continuous integration servers, and tooling to enable the creation of a local environment that mimics the production stack.

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Embracing Disruptive Innovation: OpenCredo Partners with Google

August 5, 2015 | Cloud, GCP, Kubernetes

Embracing Disruptive Innovation: OpenCredo Partners with Google

Why OpenCredo partnered with Google

Recently OpenCredo chose to partner with Google in order to share knowledge and resources around the Google Cloud Platform offerings. Our clients come in many shapes and sizes, but typically all of them realise three disruptive truths of the modern IT industry: the (economic) value of cloud; the competitive advantage of continuous delivery; and the potential of hypothesis and data-driven product development to increase innovation (as popularised by the Lean Startup / Lean Enterprise motto of ‘build, measure, learn’).

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Round up from the Kubernetes London meetup / Vol.2
How to Write Your Own Apache Mesos Framework?

February 16, 2015 | Software Consultancy

How to Write Your Own Apache Mesos Framework?

Apache Mesos is often explained as being a kernel for the data-centre; meaning that cluster resources (CPU, RAM, …) are tracked and offered to “user space” programs (i.e. frameworks) to do computations on the cluster.

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OpenCredo is pleased to announce the publication of Neo4J In Action
Experiences with Spring Boot

February 24, 2014 | Cloud Native, Microservices

Experiences with Spring Boot

Last year some of us attended the London Spring eXchange where we encountered a new and interesting tool that Pivotal was working on: Spring Boot. Since then we had the opportunity to see what it’s capable of in a live project and we were deeply impressed.

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Cucumber Android vs Appium with cucumber jvm

January 28, 2014 | Software Consultancy

Cucumber Android vs Appium with cucumber jvm

A while ago I published this blog post about writing tests for mobile applications using Appium and cucumber-jvm.

In this post, I will look at an alternative approach to testing an Android native application using Cucumber-Android.

Throughout the post I will draw comparisons between Appium and Cucumber-Android, the goal being to determine the best approach for testing an android application using Cucumber. I will focus on the ease of configuration and use, speed of test runs and quality of reporting.

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New features in Cassandra 2.0 – Lightweight Transactions on Insert

January 6, 2014 | Cassandra

New features in Cassandra 2.0 – Lightweight Transactions on Insert

The team over at Cucumber Pro recently posted a sneak peek on their blog, demonstrating some key features of their offering.

As more of a technical user of Cucumber, there isn’t much that’s new or ground-breaking for me – almost every feature is already available through your preferred IDE combined with a few plugins.

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New features in Cassandra 2.0 – More on Lightweight Transactions

December 2, 2013 | Cassandra

New features in Cassandra 2.0 – More on Lightweight Transactions

Perhaps the most important of Cassandra’s selling points is its completely distributed architecture and its ability to easily extend the cluster with virtually any number of nodes. Implementing a classical RDBMS-style transaction consisting of “put locks on the database, modify the data, then commit the transaction”-style operations are simply not feasible in such an architecture (i.e. that doesn’t scale well).

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Cross platform test automation with Appium, WebDriver and Cucumber-JVM

September 19, 2013 | Software Consultancy

Cross platform test automation with Appium, WebDriver and Cucumber-JVM

This post will give an overview of mobile testing using Appium. We will integrate tests for a native Android application into an existing Cucumber-JVM based set of acceptance tests and demonstrate multi platform testing from a single set of BDD scenarios. The sample code for this can be found here.

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Excerpt from OpenCredo-authored book Neo4J in action
Configuration Management with Flexible Contexts

August 2, 2013 | Software Consultancy

Configuration Management with Flexible Contexts

Configuration management was born in the pre-cloud era. Remember the days when acquiring a super powerful multi core server felt like winning the jackpot? Infrastructure was a slightly different place back then. Yet for all the recent developments in DevOps, its legacy is still with us.

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Running Cucumber JVM tests in parallel

July 2, 2013 | Software Consultancy

Running Cucumber JVM tests in parallel

This blog post will address the issue of slow test runs when using Cucumber JVM with web automation tools such as WebDriver to perform acceptance testing on a web application.

If your team is using continuous integration this becomes especially noticeable, forcing teams to either wait for acceptance tests to complete before deploying or having to ignore the bulk of the tests.

The sample code and description in this post will show you how to convert your suite to running tests in parallel, something which has historically been problematic with unanswered questions and outstanding Cucumber-JVM bugs on the subject. Tying the described approach in with Selenium Grid2 will allow you distribute your testing across several machines if your suite is especially large or slow.

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Model Matters: Graphs, Neo4j and the Future

February 25, 2013 | Neo4j

Model Matters: Graphs, Neo4j and the Future

As part of our work, we often help our customers choose the right datastore for a project. There are usually a number of considerations involved in that process, such as performance, scalability, the expected size of the data set, and the suitability of the data model to the problem at hand.

This blog post is about my experience with graph database technologies, specifically Neo4j. I would like to share some thoughts on when Neo4j is a good fit but also what challenges Neo4j faces now and in the near future.

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Esper Extensions – Implementing Custom Aggregation Function

March 21, 2012 | Software Consultancy

Esper Extensions – Implementing Custom Aggregation Function

Event processing Language (EPL) enables us to write complex queries to get the most out of our event stream in real time, using SQL-like syntax.

EPL allows us to use full power of aggregation of the high volume event stream to get required results with the minimal latency. In this blog we are going to explore some aspects of numerical aggregation of data with high precision BigDecimal values. We will also demonstrate how you can add you own aggregation function to Esper engine and use them in EPL statements.

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A Simple Introduction to Complex Event Processing – Stock Ticker End-to-End Sample

February 8, 2012 | Data Analysis, Data Engineering

A Simple Introduction to Complex Event Processing – Stock Ticker End-to-End Sample

Most of the important players in this space are large IT corporations like Oracle and IBM with their commercial (read expensive) offerings.

While most of CEP products offer some great features, it’s license model and close code policy doesn’t allow developers to play with them on pet projects, which would drive adoption and usage of CEP in every day programming.

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Neo4j: Super-Nodes and Indexed Relationships, Part I

June 3, 2011 | Neo4j

Neo4j: Super-Nodes and Indexed Relationships, Part I

Neo4J is one of the first graph databases to appear on the global market. Being open source, in addition to its power and simplicity in supporting graph data model it represents good choice for production-ready graph database.

However, there has been one area I have struggled to get good-enough performance from Neo4j recently – super nodes.

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