Software

Avoiding Legacy with Deployment Automation and Infrastructure-as-Code

Posted on June 19, 2012September 28, 2020 by Matthew Skelton (@matthewskelton)

Learning from ‘Working Effectively with Legacy Code’ by Michael C. Feathers

Working Effectively with Legacy Code by Michael C. Feathers is a classic software development text. Not only is it still completely relevant when working with code, seven years after it was published, but also the approaches it advocates at the source code level are becoming essential to apply at the component and system integration levels too as our software systems become more complicated and polyglot, and we learn to fully automate our deployments and treat our infrastructure as code.

Book cover: Working Effectively with Legacy Code

For an overview of the book itself, read my review of ‘Legacy Code’ on Amazon.co.uk. I describe the different sections and how each is useful in a particular context. The rest of this article will focus on other aspects of Legacy Code, particularly the ‘why’ of changing code, and the implications for Continuous Delivery, infrastructure-as-code, and deployment automation.

Continue reading Avoiding Legacy with Deployment Automation and Infrastructure-as-Code

Event-Sourced Architectures by Martin Thompson at QConLondon 2012

Posted on May 18, 2012May 18, 2012 by Matthew Skelton (@matthewskelton)

Software performance guru Martin Thompson (@mjpt777) gave an illuminating talk on event-sourced architectures, and why event-driven, state-machine designs are the way forward for complex, multi-path software systems (“Event Sourced Architectures and what we have forgotten about High-Availability”, [slides: 700KB PDF]).

Continue reading Event-Sourced Architectures by Martin Thompson at QConLondon 2012

Endpoint Discovery using Microsoft LogParser

Posted on May 9, 2012May 9, 2012 by Matthew Skelton (@matthewskelton)

A few years ago, I was working on a project for a UK client who needed to replace or rewrite a legacy inventory management web application written in classic ASP. The problem: no documentation, and complicated, spaghetti source code with many apparently duplicate or redundant ASP files and ASMX web service endpoints.

Which ASP pages were actually in use? We had to find a way to limit our application migration efforts to only those pages which were used by the application. A colleague at the time introduced me to what must be one of the best-kept secrets in the Windows developer world: Microsoft Log Parser.

Continue reading Endpoint Discovery using Microsoft LogParser

Fault tolerance, anomaly detection, and anticipation patterns by Jon Allspaw at QConLondon 2012

Posted on March 21, 2012May 15, 2012 by Matthew Skelton (@matthewskelton)

Jon Allspaw (@allspaw) from Etsy talked about the role that Anomaly Detection, Fault Tolerance and Anticipation play in producing highly scalable software systems (Fault tolerance, anomaly detection, and anticipation patterns, slides [PDF, 5MB]).

As head of technical operations at Etsy, whose web traffic is pretty substantial, Jon focused on resilience in software systems: what it is, and how to achieve it.

Continue reading Fault tolerance, anomaly detection, and anticipation patterns by Jon Allspaw at QConLondon 2012

Breaking the Monolith by Stefan Tilkov at QConLondon 2012

Posted on March 20, 2012August 20, 2012 by Matthew Skelton (@matthewskelton)

Stefan Tilkov (@stilkov) from innoQ gave an excellent talk on the importance of a “system-of-systems approach” to software architecture (Breaking the Monolith, slides [PDF, 1MB]). [Update: the video is now online here: http://www.infoq.com/presentations/Breaking-the-Monolith]

In essence, he argued for a distinction between micro-architecture (the design of the individual [sub]system) and macro architecture (the design of interacting systems).

Continue reading Breaking the Monolith by Stefan Tilkov at QConLondon 2012