The best way to familiarize yourself with Hadoop ecosystem or to do POC is to play with it in a sandbox. For that Cloudera provides 2 Quick Start options: one is the image for VirtualMashine and another is the Docker image. Both of them contain a small CDH cluster with one DataNode. But this is …
I’ve got a legacy service, written in Scala. Stack was: Play2, Scala, Slick, Postgres. Here is described why such technology stack is not the best option, what should be done to make it work better with less efforts and how to avoid underwater rocks. For impatient: If you have choice – don’t use Slick. If …
Recently I’ve finished another back-end with GraphQL, but now on Python. In this article I would like to tell you about all difficulties I’ve faced and narrow places which can affect the performance. Technology stack: graphene + flask and sqlalchemy integration. Here is a piece of requirements.txt: graphene graphene_sqlalchemy flask flask-graphql flask-sqlalchemy flask-cors injector flask-injector …
Consider the following situation: A bundle of .avro files is stored on HDFS. They need to be converted to Impala tables. Schemas are not provided with files, at least not externally (it’s contained as first line of any avro file). But Impala has a known-issue with avro tables, and its usage is pretty limited: we …
In this article I’ll describe you how to use GraphQL with Spring with this library. Full example is available here. Why annotations? From my point of view schema should not be written manually, just because it is easy to make a mistake. Schema should be generated from code instead. And your IDE can help you …
In this guide you’ll learn how to add deploy feature to the Erlang service. As a result you will get a real Erlang service, with logs in /var/log/example_service, systemd support and possibility to easy install it on every system via enot install comtihon/example_service even without Erlang installed!
This is step-by-step guide on how to create your Erlang service with the powerful Enot build system. Ensure you have Enot and Erlang installed locally. As a result you will build http service, which will listen the 8080 port and response JSON with service’s version and MAGIC_GREETING operation system’s environment variable or simple “hello world” …
Most of Erlang applications requires configuration variables. It can be: database credentials, metrics report hosts, some system limits and so on. Such variables can be set in application resource configuration file. They can be accessed with application:get_env. You should prefer dynamic configuration instead of hardcoded one. But what if you need different properties in configuration …
With this article, I would like to start a series on “Writing optimal and effective code in Erlang”. These articles are describing my point of view on the topic according to my experience in real world software development. I have been inspired by the marvelous book of M. Fowler and Co “Refactoring” if you …