by Thierry de Pauw on
Consultant at IBM Garage
These are my scary stories
One explanation of Cloud Native: SOA/ESB -> Microservices -> Cloud Native
??? lots of small services, the platform is smart and the services are dumb ???
The emphasis on micro-services for Cloud Native does not feel right
Cloud Native Foundation: micro-services, containers and dynamically orchestrated
Still does not feel right to me
If you ask 10 people what cloud native is, they will all know what cloud native is, but they will all come with a different definition. @holly_cummins
Some people will say:
- born on the cloud
- it has been build in the past 5 years, it is modern and nice
- synonym for 'cloud'
- idempotent: the problem with idempotent everyone says 'What?', you can rerun them
What is Cloud Native not? it is not a synonym for 'microservices' @holly_cummins
If cloud native has to be synonym for anything, it would be for 'idempotent' @holly_cummins
" If #cloud native has to be a synonym for anything, it should be 'idempotent'*. " #flowcon
Cloud Native Foundation mentions immutable infrastructure! and microservices examplify this behaviour
why cloud native? we want to build great products faster
make high-impact changes, frequently, ...
Bottom line is: something that allows you to "make high-impact changes frequently & predictably with minimal toil, to build great products faster". #ProductManagement https://twitter.com/ComSaraDufour/status/1329852127926247426?s=20
what problem are we trying to solve?
"everyone else is doing it?"
- It used to be a cost driver. It was cheaper because of economy of scale.
- Elasticity. You don't have to pay for things you don't use.
- Exotic capabilities. Use expensive infrastructure like quantum computers, ...
But very often, a #transformation is social-driven: "everyone's doing it so we should too". Many orgs know they want to be CN but don't know what pb to solve. https://twitter.com/ComSaraDufour/status/1329853372221022208?s=20
First cloud-movers got electrocuted.
-> 2011: 12 factors: how to write a cloud application so you don't get electrocuted
-> 2010: the dawn of cloud native
Are we all going to agree on the goal?
Microservices are not the goal, they are the means. @holly_cummins
we're going too slowly. we need to get rid of COBOL and make microservices!
... but our release board only meets twice a year
-- a bank
=> you will not actually go faster until you fix your release board
Containers are a good base. But number of containers !!???
It's not a competition to see how many you can have
=> distributed monolith
but without compile-time checking ... or guaranteed function execution
=> there is a cost to distribution
reasons not to do microservices
- small team
- not planning to release independently
- don't want complexity of service mesh - or worse yet, rolling your own
- domain model doesn't split nicely
when we change one microservice, we need to change another one
=> cloud native spaghetti
distributed does not mean decoupled
"each of our microservices has duplicated the same object model ... with twenty classes and seventy fields"
why not a common library? we don't want a common library because we don't want coupling, which is fair
but the problem was: the domain model was common over all the microservices
Micro services need Consumer-Driven Contract tests!!!
remember the a failed space program: imperial units (base) vs metric units (satellite)
CI/CD is not something you buy, it is a verb - not a tool - it is something you DO! @holly_cummins
"I'll merge my branch in our CI environment ... "
CI/CD ... CI/CD ... CI/CD ...
we release every six months ...
that is not continuous ...
@SteveSmithTech: It _could be #ContinuousDelivery if your product demand is really 6 months. If it is, you have a constraint in sales/marketing more serious than technology https://twitter.com/SteveSmith_Tech/status/1329867273432166400?s=20
@SteveSmithTech: It could also be your perception of product demand is flawed, and one way to test that would be releasing features more frequently https://twitter.com/SteveSmithTech/status/1329867598268428290?s=20
How often should you integrate?
there is a spectrum
- actually continuous ... but stupid
- every character
- every commit (several times an hour)
- every few commits (several times a day)
- once a day => trunk-based development
- once a week
- once a month
- once every six month
How often should you release?
there is also a spectrum
- every push (many times a day) -> need a good handle on feature flags
- every user story
- every epic
- once a sprint
- once a quarter
- once every two years: old school
How often should you test in staging?
there is not really a spectrum on that -> continuously
We can't release? But why? Why can't you deploy more often?
we can't release this microservice ...
we deploy all our microservices at the same time.
The point of Cloud Native is ... speed
What's the point of an architecture that is expensive and that enable you to go faster but you don't go faster?
=> you don't get feedback
Feedback is good engineering
Feedback is good business
CI/CD is a verb —not a tool—, it's something you DO!
Feedback is good #engineering and good #business. #cicd #tech #flowcon #ProductManagement https://twitter.com/ComSaraDufour/status/1329857162005327885?s=20
If it is too scary to deploy? defer wiring, use feature toggles, use A/B tests
our tests are not automated, we don't know if our code works
oh yes, that build has been broken for a few weeks ...
systems are going to behave in unexpected ways
with microservices you need to have these automated contract tests
Companies put too much Governance on cloud
Provisioning tool does not work because ...
84-step pre-approval process before provisioning
we're going to change cloud provider to fix our procurement process
If the developers are the only one changing, it is not going to work
It has a cost. Developers will leave.
The cloud makes it so easy to provision hardware.
That doesn't mean the hardware is free or useful -> it has a cost
Hey boss, I created a Kubernetes cluster ... I forgot about it ... 2 months later I realised it cost 1000 USD per month
2017 survey: 25% of 16.000 servers doing no useful work
-> financial impact and climate impact
and that is why there is governance
There is surely nothing quite so useless as doing with great efficiency what should not be done at all.
-- Peter Drucker
we have no idea how much we're spending on cloud
=> cloud for managing cloud costs
make releases deeply boring so that we can do them often
But our use case is special ...
in most cases there are good recoverable
space: not recoverable
most other cases: are recoverable
hand-offs bad, automation is good => allows to release often
You have to have that clear goal of what you want to achieve
Optimise for feedback
Look at the whole system -> Systems Thinking.
If you automate something, change the processes around that assume that the previously manual process is expensive and error prone.
The objective is: Optimise the system as a whole