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27 items found: Search results for "actor model" in all categories x

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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Patterns of Successful Cassandra Data Modelling

September 6, 2016 | Cassandra

Patterns of Successful Cassandra Data Modelling

A growing number of clients are asking OpenCredo for help with using Apache Cassandra and solving specific problems they encounter. Clients have different use cases, requirements, implementation and teams but experience similar issues. We have noticed that Cassandra data modelling problems are the most consistent cause of Cassandra failing to meet their expectations. Data modelling is one of the most complex areas of using Cassandra and has many considerations.

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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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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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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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Akka Typed brings type safety to Akka framework

January 18, 2016 | Software Consultancy

Akka Typed brings type safety to Akka framework

Last time in this series I summarised all the Akka Persistence related improvements in Akka 2.4. Since then Akka 2.4.1 has been released with some additional bug fixes and improvements so perhaps now is a perfect time to pick up this mini-series and introduce some other new features included in Akka 2.4.x.

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Automation of complex IT systems

May 14, 2020 | Blog, DevOps

Automation of complex IT systems

At the time of this post, the UK is making steps to exit from an unprecedented lockdown measures for the Coronavirus. Much of the UK workforce are still making efforts to work-from-home with mainly key workers operating – at risk – in public. Many industries have shut down completely. Consequently, many businesses are reflecting on what happens next and how do we better mitigate future pandemic events?

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Why Upgrading to Terraform 0.12+ Should be a Priority

October 3, 2019 | Cloud, DevOps, Hashicorp, Open Source

Why Upgrading to Terraform 0.12+ Should be a Priority

Terraform 0.12 in recent years has emerged as the de facto standard with regards to defining and managing cloud infrastructure. It is one of four primary tools offered by HashiCorp, (Terraform, Vault, Consul and Nomad) and underpins the workflows that make up their Cloud Operating Model.

Since its first release in 2014, the wider Terraform community has embraced frequent releases and this past year has been no exception. HashiCorp announced the release of Terraform 0.12 in May 2019 and as of writing this post the official release is 0.12.9.

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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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Data Science on Steroids: Productionised Machine Learning as a Value Driver for Business

July 31, 2018 | Machine Learning

Data Science on Steroids: Productionised Machine Learning as a Value Driver for Business

Machine Learning, alongside a mature Data Science, will help to bring IT and business closer together. By leveraging data for actionable insights, IT will increasingly drive business value. Agile and DevOps practices enable the continuous delivery of business value through productionised machine learning models and software delivery.

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Get your -aas in gear: Privatelink and PaaS democratisation on AWS

February 6, 2018 | Cloud

Get your -aas in gear: Privatelink and PaaS democratisation on AWS

Among the many announcements made at Re:Invent 2017 was the release of AWS Privatelink for Customer and Partner services. We believe that the opportunity signalled by this modest announcement may have an impact far broader than first impressions suggest.

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A Pragmatic Introduction to Machine Learning for DevOps Engineers

January 23, 2018 | Data Engineering, DevOps

A Pragmatic Introduction to Machine Learning for DevOps Engineers

Machine Learning is a hot topic these days, as can be seen from search trends. It was the success of Deepmind and AlphaGo in 2016 that really brought machine learning to the attention of the wider community and the world at large.

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Writing a custom JupyterHub Spawner

January 11, 2018 | Data Engineering

Writing a custom JupyterHub Spawner

The last few years have seen Python emerge as a lingua franca for data scientists. Alongside Python we have also witnessed the rise of Jupyter Notebooks, which are now considered a de facto data science productivity tool, especially in the Python community. Jupyter Notebooks started as a university side-project known as iPython in circa 2001 at UC Berkeley.

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Terraform Provider Development

August 9, 2017 | Cloud, DevOps, Terraform Provider

Terraform Provider Development

The recent 0.10.0 release of HashiCorp Terraform, saw a significant change to the way Providers are managed. Specifically, the single open source code repository for Terraform has been divided into core and multiple provider repositories.

 

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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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CockroachDB: First Impressions

June 15, 2017 | Data Engineering

CockroachDB: First Impressions

CockroachDB is a distributed SQL (“NewSQL”) database developed by Cockroach Labs and has recently reached a major milestone: the first production-ready, 1.0 release. We at OpenCredo have been following the progress of CockroachDB for a while, and we think it’s a technology of great potential to become the go-to solution for a having a general-purpose database in the cloud.

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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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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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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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What’s new in Akka Persistence 2.4

October 28, 2015 | Software Consultancy

What’s new in Akka Persistence 2.4

Let’s have a quick look at the most interesting changes and new features that are now available to Akka users. As there are many new features to highlight in the new Akka release I will focus on those related to Akka Persistence first and cover other areas in a separate post.

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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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Software Circus: Thinking Fast and Slow with Software Development

September 13, 2015 | DevOps

Software Circus: Thinking Fast and Slow with Software Development

Making Good Decisions within Software

Last week I was privileged to be able to present my “Thinking Fast and Slow with Software Development” talk at the inaugural Software Circus conference in Amsterdam. The conference was amazing, and I’ll write more about this later, but in this post I was keen to share the presentation slides and the thinking behind this talk…

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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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November 19, 2014 | Microservices

The 7 Deadly Sins of Microservices

Undeniably, there is a growing interest in microservices as we see more organisations, big and small, evaluating and implementing this emerging approach. Despite its apparent novelty, most concepts and principles underpinning microservices are not exactly new – they are simply proven and commonsense software development practices that now need to be applied holistically and at a wider scale, rather than at the scale of a single program or machine. These principles include separation of concerns, loose coupling, scalability and fault-tolerance.

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Spring Data Hadoop – Objective Overview

June 30, 2013 | Software Consultancy

Spring Data Hadoop – Objective Overview

Spring Data Hadoop (SDH) is a Spring offshoot project that allows the invocation and configuration of Hadoop tasks within a Spring application context. It offers support for Hadoop jobs, HBase, Pig, Hive, Cascading and additionally JSR-223 scripting for job preparation and tidy-up.

It is most suited for use in organisations with existing Spring applications or investment in Spring expertise. Some SDH features replicate functionality of tools in the Hadoop ecosystem that DevOps engineers who maintain a Hadoop cluster will be more familiar with.

 

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