An illustrated guide to microservices (ploneconf 10 21-2016)

An Illustrated Guide to Microservices

Philip LombardiEngineering

datawire.io

Background...

1. Philip Lombardi @ Datawire.io (twitter: @TheBigLombowski)

2. Datawire.io is building a Microservices Development Kit to enable developers to build resilient microservice applications.

3. Check us out after meetup: https://datawire.io

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This is a Python talk… really...

1. Datawire is a first-class Python shop.

2. We love Python so much, we use it to write code in other languages (yes, we have a compiler written in Python).

3. Python & Microservices complement each other really well.

4. Time permitting I’ll do some demo’s with Python microservices...

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What’s a Microservice?

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Common Microservice Definitions

It’s a service that is...

● Small● Self contained● Narrow in scope● Bounded context● Independent● Loosely coupled

Correct, but incomplete...

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Common Microservice Definitions (as applied to Legos)

A piece of plastic that is…

● Small● Self contained● Narrow in scope● Bounded context● Independent● Loosely coupled

What’s missing…?

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A (simpler) Microservices Definition

A Microservice is a unit of business logic.

A Microservice application is a distributed composition of business logic via services.

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Combine to build AWESOME!

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What do you get when you combine Microservices?

Topologies!

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Death Star Topology

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Wait, why do I want a death star?

Maybe you don’t, but your CXO does

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Organizational Scale

AgilityVelocity

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Topologies

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Topologies have always been a thing

● Topologies aren’t new, they have always been the bread and butter of distributed systems design

● In fact we’ve all been stuck living in the same topology for a while now

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Topologies are powerful

Information flows through topologies like water through a pipe or current on a wire

Probably the most important factor in the performance of a distributed system

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Topologies are the purview of the Elite

Architects define the topology

Developers get to plug in business logic in a few predefined places

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Microservices bring topology to Developers

Developers define the topologyBusiness logic is distributed rather than being centralized

The topology changes and grows much more quickly

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Topologies can solve a lot of problems

IntegrationOperational Scale

Reliability

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Operational Scale (Linear Topology)

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Ingest Source of Truth Transform Present

Template for many data driven businesses…

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Operational Scale (Linear Topology)

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Ingest Source of Truth Transform Present

Template for many data driven businesses…

Network Disk Disk + CPU Network + CPU

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Scale Components Independently

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Ingest Source of Truth Transform Present

Template for many data driven businesses…

Network Disk Disk + CPU Network + CPU

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Integration (Fan Out Topology)

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Reliability

Software Bug

Centralized Business Logic can be a Single

Point of Failure

Operational Failure

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Reliability

Software Bug

Decentralize Business Logic to Isolate Failures

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Organizational Scale

Software Bug

Decentralized Business Logic Means● Multiple Teams● Smaller Codebases● Ramp up Developers Faster

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Can topologies give me a death star?

They help, but not quite… you need to build topologies quickly!

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Organizational Scale

AgilityVelocity

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Microservices vs SOA(Service Oriented Architecture)

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Common Explanations

Both are topologies of services

● Fine grained SOA● Integration pattern vs application components● Organizational factors...

We need a better definition…

● These explanations ignore the process that yields the topology

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Architecture and Development are different processes

Both can yield topologies of services, but SOA won’t build your death star. For that you need agile topologies

Microservices: Service Oriented Development

Architecture:

● Lots of up front thinking● Slow iteration cycle● Months/years until you get feedback

Development:

● Experimental● Rapid iteration cycle● Minutes/hours until you get feedback

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You need a new Mindset and new Tooling

So, how do I build Agile Topologies?

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Mindset

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What’s the new Mindset?

The role of architecture changes

● An architect’s job is to enable developers, not confine them● Architecture teams -> developer infrastructure, developer happiness, …

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Up Front Thinking Experimentation

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Tooling

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What tools enable experimentation & rapid iteration?

You need three things when you decentralize your business logic:

1. A way to make your topology resilient to software bugs○ Where does my catchall go?○ Minimize impact of bugs reaching production○ Graceful degradation instead of catastrophic failure

2. A robust tool for deployment pipelines that enables both service and system level testing○ Where do your integration tests go?

3. Good visibility into the state of the running system○ Where does my printf go?

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How do you build these tools?

It’s all about how you manage your topology

● Transition from DNS -> Discovery● Central load balancers -> Smart Endpoints

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Routing table is (relatively) static

Routing policy is global

Traditional Topology Management

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Client

DNS

Load Balancer

Serverresolve

traffic

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Routing table is updated in realtime

Routing policy is local

Microservices Topology Management

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Client

DiscoveryServer

heartbeatsroutes

Smart Endpoint

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Demo

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Summary

Useful definitions:

● Microservice: A node in an Agile Service Topology● Microservices: Service Oriented Development

How to build a death star (trifecta of velocity, agility, and organizational scale):

● Mindset: architecture -> experimentation● Tooling: Discovery + Smart Endpoints

With these tools you can get started in half an hour instead of spending six months rearchitecting

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To learn more

Contact me:

● plombardi@datawire.io● Twitter: @TheBigLombowski

Jobs

● https://www.datawire.io/careers/○ Python, Java|Scala|Kotlin, Go and Kubernetes Developers Wanted!○ Hiring for DevOps | SRE role!

Try

● https://github.com/datawire/mdk● https://www.datawire.io

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