I recently posted a review of Patterns for Performance and Operability by Ford et al on the SoftwareOperability website. I think that this book is exceptionally useful in its treatment of both performance and operability, and anyone who cares about how well software works in Production should buy and read a copy (there are paper and eBook editions).
Two other reviews might be useful too: my colleague Anant East (Head of Architecture and Infrastructure, thetrainline.com) wrote up a detailed review of Patterns for Performance and Operability on the tech blog at thetrainline.com, and I posted a short review on Amazon.
I attended QConLondon 2013 last week; what I took from the first four sessions in the Building for Clouds track was: cloud API and infrastructure automation tools have now solved most of the ‘easy’ cloud problems, but harder challenges (such as automating clusters) remain. The sessions were from Tim Savage (@timjsavage) and Zenon Hannick (@zenonhannick) on Comic Relief’s unique challenges with performance testing, Gareth Rushgrove (@garethr) on how to avoid PaaS lock-in, Stephen Nelson-Smith (@LordCope) on how to use Chef to give you ‘optionality’ with different cloud vendors, and Andrew Crump (@acrmp) and Chris Hedley (@ChristHedley) on the CloudFoundry cloud platform.
Continue reading Comic Relief, @garethr, @LordCope, and CloudFoundry at QConLondon 2013
This article first appeared in Software Development Practice, Issue 1, published by IAP (ISSN 2050-1455)
When raising log events in code it can be difficult to choose a severity level (such as Error, Warning, etc.) which will be appropriate for Production; moreover, the severity of an event type may need to be changed after the application has been deployed based on experience of running the application. Different environments (Development (Dev), User Acceptance Testing (UAT), Non-Functional Testing (NFT), Production, etc.) may also require different severity levels for testing purposes. We do not want to recompile an application just to change log severity levels; therefore, the severity level of all events should be configurable for each application or component, and be decoupled from event-raising code, allowing us to tune the severity without recompiling the code.
A simple way to achieve this power and flexibility is to define a set of known event IDs by using a sparse enumeration (enum in C#, Java, and C++), combined with event-ID-to-severity mappings contained in application configuration, allowing the event to be logged with the appropriate configured severity, and for the severity to be changed easily after deployment.
Continue reading Tune logging levels in Production without recompiling code
I recently went to a Devs in the ‘Ditch meetup at 7digital to hear Chris O’Dell (@ChrisAnnODell) explain 7digital’s journey to Continuous Delivery and Steve Freeman (@sf105) speak on GOOS and system testing. We had some useful discussions on dependency injection and how to use logging well, and Steve’s perspectives on ‘code shapes’ and the purpose of tests were revealing.
Continue reading GOOS at 7digital – Code Shapes, the Purpose of Tests, and Logging Done Well
It was a privilege to be part of the first WebPerfDays EU in London on 5th October 2012. Together with the folks from CCPGames, I facilitated a session on Continuous Delivery, opening the discussion with an overview of how build & deployment shapes software architecture at thetrainline.com:
The Continuous Delivery session prompted some excellent discussions around CD; there seems to be interest in setting up a London-based meetup, which I agreed to help coordinate.
Kudos to Steve Thair (@TheOpsMgr) and team for organizing such an excellent event.