Development and QA dilemmas in DevOpsMatteo Emilitwitter.com/MattVSTS || mattvsts.blogspot.com

Who am I?

Visual Studio and Development Technologies MVP (ALM)

Professional Scrum Master I Systems Engineering Advisor @ Dell Software

Taunton Developers Meetup London Microsoft DevOps Meetup Other communities overseas

CD Cycle

REQUIREMENTSPRODUCTBACKLOG

OPSBACKLOG

MonitorImplement

WORKING SOFTWARE

DefineIdeation

DevelopIdea to working software

OperateWorking software in productionValue realization

Are we all ready for it?

Sometimes things are the other way round…

The first thing to do should be creating a Minimum Viable Product, including the infrastructure

The Pipeline must work from the very first moment Dev and Test environments should be disposable,

infrastructure must be idempotent Testing can happen in Production

It is a shocking change for some

“I was frightened by not feeling a safety net” “Does it actually work?” “The feeling is not good at first” “We don’t want to be accountable for all of this” “It can’t work!” “How do we know what to build?” “It is hard to get the grip with these tools”

PrerequisiteThe team must buy into DevOps!

Scenario #0

Use your infrastructure!

Leverage on Infrastructure As Code (DSC, Azure RM, Amazon CloudFormations) to remove friction when factoring the infrastructure in

Spend time on defining what you need to have, and the provider (Azure, AWS, local deployment service) will deploy that for you

Idempotent and resilient – if there is something wrong, redeploy

Less friction here means no barrier between Dev and Ops, a fundamental (and time saving) change!

Scenario #1

Database schema change

You must bring a database schema change in production

Cloud or mission critical web service Transparent for your users, regardless of public-facing

or internal change No downtime for migration – it must work!

The typical approach

Develop everything in a separate environment Countless hours of tests Big-bang migration then new feature for all the users Big release date, people freak out …lots of fingers crossed!

Shhh! Don’t make noise!

There is no such approach in DevOps Each big change must be split in smaller changes

They are often invisible to the user Silent deployments can happen across multiple

sprints If something breaks, rollback Start using your MVP straight away!

DemoInfrastructure as CodeDatabase schema change

Scenario #2

Feature Flags

Championed by Martin Fowler, Feature Flags are around since at least 2009

Pretty much all services nowadays use them Flickr, Amazon, Microsoft, Facebook, Google, Netflix … They are used to enable or disable certain areas of

your application to your users

“…wait. Does it mean Microservices and all the new stuff around?”

No, it doesn’t! You can use Feature Flags with all the architectures It is a practice, not a product It ties in with the previous scenario and makes testing

easier

How?

Practically speaking, it is about a Configuration Database coupled with Identifiers

The Configuration Database can be a csv file, XML file, key-value model, a database (!)

Identifiers are areas you will easily split your applications into

They often go well together with Feature/Epics or even User Stories

Countless OSS libraries

It doesn’t come for free

It is expensive (in terms of time, and sometimes refactoring) to build it up from scratch in an existing application

Not just enable/disable – logging, kill switch, selective adoption, rollouts are all things to implement that takes time

OSS libraries help, as there is a choice for each platform, but there is still an implementation cost to keep in mind

DemoFeature Flags with LaunchDarkly

Scenario #3

A/B Testing, MVT Testing…is it about testing?

Little changes for QA in DevOps, except for automation

What is really new are practices of Testing in Production - extremely common especially with Web Applications

You deploy version B of your A application (or a permutation of possibilities), direct a percentage of the traffic towards it and compare the adoption results

Implementing them is extremely easy, getting value out of them is hard!

A bit of Lean…

"There is no such thing as a free lunch“ – technology alone is not going to deliver a successful product

My take is to adopt the Build-Measure-Learn loop Start with a Minimum Viable Product and measure its

usage with appropriate metrics Build on top of it, discard what doesn’t work

Getting visibility on what is actually happening

Is my application performing as expected? What about availability? Are my users having a good experience?

Above all, you need better, faster and more direct feedback

Learn from your users and improve your product

In the Build-Measure-Learn loop the Measure stage is the most important one

Metrics will tell if you are going in the right direction, so it is critical to ‘get it right’

Extend your product to include what really matters Get insights on your users before they react Proactively understand potential problems

You can analyse your data and understand if your application is behaving as expected

It is different from logging

We are not talking about plain application logs What user actions are meaningful to your business

goals? Is the telemetry data answering this question? Is there any bottlenecks which is penalising the

business? You need to have visibility on user events

Actionable insights are mapped into behaviours (what content is used, not how)

E.g.: when a user enters in a certain page/area, log on/off, Favourites, social stats, errors…

You won’t do that from scratch

It is too expensive to build something from scratch You need to use an analytics provider The development experience must be cross-platform,

unobtrusive at first and then customisable with an SDK

Easily add custom telemetry wherever needed

DemoLearn from your users

So?

These scenarios are very common when approaching DevOps

Remember: DevOps is not the silver bullet, teams must buy-in into the process

Collaboration is key to success Use data to take decisions Don’t be afraid!