Microservice Integration and How to Avoid Them @berndruecker Bernd - - PowerPoint PPT Presentation

3 Common Pitfalls in Microservice Integration and How to Avoid Them

@berndruecker

Berlin, Germany

bernd.ruecker@camunda.com @berndruecker

Bernd Ruecker

Co-founder and Developer Advocate of Camunda

REST, SOAP, Cloud, Saas, Microservices, SCS, FaaS, Serverless, …

Distributed systems

https://www.infoworld.com/article/3254777/application-development/ 3-common-pitfalls-of-microservices-integrationand-how-to-avoid-them.html

Distributed systems

Challenges of asynchronicity Distributed T ransactions Communication is complex

Some Service Some Service Some Service Some Service Some Service Some Service Some Service

Failure will happen. Accept it! But keep it local! Be resilient.

Let‘s start with a simple example

Credit Card Payment

REST

Live hacking

https://github.com/berndruecker/flowing-retail

Circuit Breaker

Photo by CITYEDV, available under Creative Commons CC0 1.0 license.

Fai ail f l fast is important

Fai ail f l fast is important but not enough!

Photo by Tookapic, available under Creative Commons CC0 1.0 license.

„There was an error while sending your boarding pass“

Check-in Web-UI

Me

Current situation

Check-in

Barcode Generator

Web-UI

Me

Output Mgmt

Current situation

Check-in

Barcode Generator

Web-UI

Me

Output Mgmt

Current situation

Check-in

Barcode Generator

Web-UI

Me

Output Mgmt

Current situation

Circuit breaker

Check-in

Barcode Generator

Web-UI

Me

Output Mgmt

Current situation – the bad part

Check-in

Barcode Generator

Web-UI

Me

Output Mgmt

Current situation – the bad part

Check-in

Barcode Generator

Web-UI

Me

Output Mgmt

Current situation – the bad part

Stateful Retry

We are having some technical difficulties and cannot present you your boarding pass right away. But we do actively retry ourselves, so lean back, relax and we will send it

• n time.

Check-in

Barcode Generator

Web-UI

Me

Output Mgmt

Possible situation – much better!

Check-in

Barcode Generator

Web-UI

Me

Output Mgmt

Possible situation – much better!

Stateful Retry

Check-in

Barcode Generator

Web-UI

Me

Output Mgmt

Stateful Retry

Possible situation – much better!

The failure never leaves this scope!

Persist thing (Entity, Document, Actor, …) State machine or workflow engine T ypical concerns DIY = effort, accidental complexity Complex, proprietary, heavyweight, slow, don‘t scale, developer adverse

Scheduling, Versioning,

• perating, visibility,

scalability, …

Handling State

Workflow engines, state machines

It is

relevant

in modern architectures

CADENCE

Silicon valley has recognized

Workflow engines, state machines

CADENCE

Workflow engines, state machines

CADENCE

also at scale

Workflow engines, state machines

CADENCE

for todays demo

Workflow engines, state machines

Live hacking

https://github.com/berndruecker/flowing-retail

Payment

Now you have a state machine!

Credit Card

REST

has to implement

Retry

has to implement

Idempotency

Client Service Provider

We are processing your payment. Do not leave this page. And for god sake – do not reload!

It is a business problem anyway!

We are processing your payment. Do not leave this page. And for god sake – do not reload!

It is a business problem anyway!

We are currently processing your request. Don‘t worry, it will happen safely – even if you loose connection. Feel free to reload this page any time!

Requirement: Idempotency of services!

Photo by pixabay, available under Creative Commons CC0 1.0 license.

Requirement: Idempotency of services!

Photo by Chr.Späth, available under Public Domain.

Distributed systems introduce complexity you have to tackle!

Credit Card Payment

REST

Distributed systems

It is impossible to differentiate certain failure scenarios.

Independant of communication style!

Service Provider Client

Distributed systems introduce complexity you have to tackle!

Credit Card Payment

REST

Distributed systems introduce complexity you have to tackle!

Credit Card Payment

REST

BPMN

Business Process Model and Notation ISO Standard

BPMN

Executable and mature Easy to understand* Widespread

*(for Biz, Dev, and Ops)

Proper Operations

Visibility + Context

Compare to e.g. Step Functions

Workflows live within service boundaries

Credit Card Payment

REST

Check-in Barcode Generato r Web-UI

Me

Output Mgmt

Workflows live within service boundaries

Check-in Barcode Generato r Web-UI

Me

Output Mgmt

Workflows live within service boundaries

Manigfold architecture options

https://blog.bernd-ruecker.com/architecture-options-to-run-a-workflow-engine-6c2419902d91

Manigfold architecture options

https://blog.bernd-ruecker.com/architecture-options-to-run-a-workflow-engine-6c2419902d91

Manigfold architecture options

https://blog.bernd-ruecker.com/architecture-options-to-run-a-workflow-engine-6c2419902d91

Manigfold architecture options

https://blog.bernd-ruecker.com/architecture-options-to-run-a-workflow-engine-6c2419902d91

generateBoardingPass HTTP 200 OK HTTP 202 ACCEPTED

Check-in

Happy case: Synchronous response Otherwise: asynchronous

„The customer wants a synchronous response“

Check-in

Barcode Generator

Web-UI

Me

Output Mgmt

„Eh – no!“

Synchronous communication is the crystal meth of distributed programming

T

• dd Montgomery and Martin Thompson

in “How did we end up here” at GOT

O Chicago 2015

Challenges of asynchronicity

Check-in

Barcode Generator

Web-UI

Me

Output Mgmt

Asynchronous communication

You need to monitor timeouts

Check-in

Barcode Generator

Web-UI

Me

Output Mgmt

Remember…

The failure never leaves this scope!

Workflow…

Workflow…

has to implement

Timeout, Retry

has to implement

Idempotency

Client Service Provider

Who uses a message bus?

Who has no problems

• perating a message bus?

Dead messages | No context | Inaccesible payload | Hard to redeliver | Home-grown message hospitals | …

Manigfold architecture options

https://blog.bernd-ruecker.com/architecture-options-to-run-a-workflow-engine-6c2419902d91

Manigfold architecture options

https://blog.bernd-ruecker.com/architecture-options-to-run-a-workflow-engine-6c2419902d91

Manigfold architecture options

https://blog.bernd-ruecker.com/architecture-options-to-run-a-workflow-engine-6c2419902d91

Avoids th thundering ering her erds

Photo by Gopal Vijayaraghavan, available under Creative Commons BY 2.0 license.

Photo by Gopal Vijayaraghavan, available under Creative Commons BY 2.0 license. https://aws.amazon.com/de/message/5467D2/

Distributed T ransactions Distributed T ransactions

Distributed systems

Pat Helland

Grown-Ups Don’t Use Distributed T ransactions

“

Distributed Systems Guru Worked at Amazon, Microsoft & Salesforce

Distributed transactions using compensation *

Compensation

Eventual consistency

T emporarily inconsistent state But only temporarily!

Live hacking

https://github.com/berndruecker/flowing-retail

has to implement

Timeout, Retry, Compensation

has to offer

Compensation

has to implement

Idempotency

Client Service Provider

has to implement

Timeout, Retry, Compensation

has to offer

Compensation

has to implement

Idempotency

Client Service Provider

Don‘t forget about state

Event-driven example also available

Inventory Payment Order Shipping Checkout Monitor

https://github.com/flowing/flowing-retail/

Human T asks

H2 H2

Workflows live inside service boundaries

Sales-Order & Order-Fulfillment via Camunda for every order worldwide (Q2 2017: 22,2 Mio)

# Be aware of complexity of distributed systems # Know strategies and tools to handle it

e.g. Circuit breaker (Hystrix) Workflow engine for stateful retry, waiting, timeout and compensation (Camunda)

Thank you!

mail@berndruecker.io @berndruecker https://berndruecker.io https://medium.com/berndruecker https://github.com/berndruecker

https://www.infoq.com/articles/events- workflow-automation

Contact: Slides: Blog: Code:

https://www.infoworld.com/article/3254777/ application-development/ 3-common-pitfalls-of-microservices- integrationand-how-to-avoid-them.html https://thenewstack.io/5-workflow-automation- use-cases-you-might-not-have-considered/