Uploaded byBernd Ruecker
JCon 2017: Let your microservices flow
The document discusses microservices and distributed systems. It recommends using microservices and breaking an application into domains like checkout, payment, inventory, and shipping. It describes challenges with distributed systems like unreliable networks and the need for circuit breakers. It also discusses approaches to handling state in distributed systems like using entities, actors, and state machines. It presents event-driven and command-based architectures with messaging buses and recommends lightweight tools. In general, it advocates for embracing events, commands, asynchronous communication and state machines to address challenges with distributed systems.
More Related Content
Similar to JCon 2017: Let your microservices flow
JCon 2017: Let your microservices flow
- 1. Let your microservicesflow! mail@bernd-ruecker.com With thoughts from http://flowing.io @berndruecker | @martinschimak
- 3. Simplified example: dash button Photoby 0xF2, available under Creative Commons BY-ND 2.0 license. https://www.flickr.com/photos/0xf2/29873149904/
- 4. Let‘s asume wego for microservices. Because: Reasons.
- 5.
- 6. Let‘s zoom intothe payment public void retrievePayment(String customerId, long amount) { long remainingAmount = useExistingCustomerCredit(customerId, amount); if (remainingAmount > 0) { try { chargeCreditCard(customerId, remainingAmount); } catch (CreditCardExpiredException ex) { restoreCustomerCredit(customerId, amount-remainingAmount); throw new PaymentFailedException(); } } }
- 7. Let‘s zoom intothe payment public void retrievePayment(String customerId, long amount) { long remainingAmount = useExistingCustomerCredit(customerId, amount); if (remainingAmount > 0) { try { chargeCreditCard(customerId, remainingAmount); } catch (CreditCardExpiredException ex) { restoreCustomerCredit(customerId, amount-remainingAmount); throw new PaymentFailedException(); } } } Remote Service
- 8.
- 9. Distributed systems arehard. You will be screwed. But you cannot avoid it.
- 10. public void retrievePayment(StringcustomerId, long amount) { long remainingAmount = useExistingCustomerCredit(customerId, amount); if (remainingAmount > 0) { try { chargeCreditCard(customerId, remainingAmount); } catch (CreditCardExpiredException ex) { restoreCustomerCredit(customerId, amount-remainingAmount); throw new PaymentFailedException(); } } } Unreliable networks require some extra work Circuit breaker & fail fast
- 11.
- 12. public void retrievePayment(StringcustomerId, long amount) { long remainingAmount = useExistingCustomerCredit(customerId, amount); if (remainingAmount > 0) { try { chargeCreditCard(customerId, remainingAmount); } catch (CreditCardExpiredException ex) { restoreCustomerCredit(customerId, amount-remainingAmount); throw new PaymentFailedException(); } } } Unreliable networks require some extra work Circuit breaker & fail fast Retry capability & async behavior Distributed transactions
- 13.
- 14. Persist state with Entity,Actor, … State machine How to implement? DIY
- 15.
- 16. Example * Modeled inBPMN ISO Standard for modeling and execution
- 17. Long running requirespersistent state
- 18.
- 19.
- 20.
- 21. Timeouts and longrunning requirements
- 22. State machines solvesome hard developer problems Monitoring & Operations Handling of time & timeouts Retry Visibility & Reporting Versioning Compensation Message correlation & deduplication Performance & scalability
- 23. State machines solve somehard developer problems. Distributed systems pose some hard problems on developers!
- 24.
- 27. A visual testreport for example #1 (Balance = 50, Amount = 70)
- 28. Look for lightweight, developerfriendly tools
- 29.
- 30. Asynchronous Checkout Payment InventoryShipping Bus
- 31. Event-Driven Checkout Payment InventoryShipping Bus Order Placed Does not know recipient Does not know sender Smart endpoints and dumb pipes Event: Fact that happened in the past, Immutable fact, 0..n recepients Order Placed Does know event type…
- 32. Event-Driven – thegood parts Checkout Payment Inventory Shipping Bus Amount OnStock Changed „The button blinks green if we can ship the item within 24 hours!“
- 33. End-to-end capabilities usingpeer-to-peer event flows? InventoryPayment ShippingCheckout Order placed Payment received Goods fetched Goods shipped
- 34. Shipping End-to-end capabilities usingpeer-to-peer event flows? InventoryPaymentCheckout Order placed Payment received Goods fetched Please fetch the goods before waiting for payment Some customers can pay via invoice …
- 35. InventoryPayment ShippingCheckout Bus Order Order Placed Retrieve Payment Event CommandTransformation Command: Intent, 1 recipient. Retrieve Payment Fetch Goods Ship Goods Does not know sender Just knows command type…
- 36. Commanding is important! InventoryPaymentShippingCheckout Bus Ship Goods Order Order Placed Retrieve Payment „A few smart god services tell anemic CRUD services what to do!” Sam Newman
- 37. The problem isnot orchestration! The problem is bad API design.
- 38. Orchestration is notabout synchronous request and response. It is a about commands and probably long running flows. And yes – it can be reactive.
- 39.
- 40.
- 41. Payment Flows are ownedby services Order
- 42.
- 43. Messaging under control? Photoby Andy Simmons, available under Creative Commons BY 2.0 license.
- 44. External task workerexample Stripe Worker Payment Rest Node.js Java A possibility in your toolbox. Pro: Easy to do, no AMQP or Kafka required for bus Con: Coupling to Camunda API
- 45.
- 46. Container (e.g. Tomcat, WildFly,Websphere, …) Architecture possibilities Your application Engine DB BPMN Java … Your application Engine DB BPMN Java … Engine (Docker, Tomcat, …) Your application DB Embedded engine Container managed engine Remote engine BPMN Java, C#, Go, JS, …
- 47. New kid onthe block https://zeebe.io/ Zeebe Broker Your application Binary (MsgPack) Support streaming & batching Client Horiziontally scalable Append only log / event sourcing
- 49. Distributed systems are hard State machines solvehard developer problems Can run decentralized And provide visibility sync and async
- 50.
- 51. Code: https://github.com/berndruecker Slides: https://bernd-ruecker.com Blog: https://blog.bernd-ruecker.com Feedback: https://bernd-ruecker.com/feedback With thoughts fromhttp://flowing.io @berndruecker | @martinschimak
- 52. Images licensed fromiStock no attribution required Images licensed under Creative Commons license All icons licensed from Noun Project no attribution required Photo by Andy Simmons, available under Creative Commons BY 2.0 license. https://www.flickr.com/photos/andysimmons /4630485117/