Category: Cloud

2016-11-07T17:27:07Z

How to Retry with Class

Highly distributed applications that consist of lots of small services talking among themselves are getting more and more popular, and that, in my opinion, is a good thing. But this architectural style brings with it a new class of problems that are less common in monolithic applications. Consider what happens when a service needs to send a request to another service, and this second service happens to be temporarily offline, or too busy to respond. If one little service goes offline at the wrong time, that can create a domino effect that can, potentially, take your entire application down.

In this article I'm going to show you techniques that can give your application some degree of tolerance for failures in dependent services. The basic concept is simple: we make the assumption that in most cases these failures are transient, so then when an operation fails, we just repeat it a few times, until it hopefully succeeds. Sounds easy, right? But as with most things, the devil is in the details, so keep reading if you want to learn how to implement a robust retry strategy.

How to Retry with Class

7 comments

2014-08-04T05:58:08Z

The Rackspace Cloud API

Most of you know by now that not too long ago I joined Rackspace. As you can imagine, I am now learning tons of new things as I familiarize myself with all the OpenStack projects, none of which I have used before.

In this article I'm going to show you a few ways to work more efficiently with your Rackspace cloud account (or any OpenStack cloud for that matter). I will begin with the introduction of a command line tool that you can use to manage your cloud servers, and then go even lower level and show you how you can do the same thing using a Python SDK. To end this article I'm going to show you a complete script that creates a cloud server, configures it as a Web server and deploys a Flask application to it, all completely unattended.

3 comments

2013-04-24T06:24:58Z

The Flask Mega-Tutorial, Part XVIII: Deployment on the Heroku Cloud

This is the eighteenth article in the series in which I document my experience writing web applications in Python using the Flask microframework.

The goal of the tutorial series is to develop a decently featured microblogging application that demonstrating total lack of originality I have decided to call microblog.

119 comments