Speaker: Damian Dziaduch Reliable communication 

“Heya, I’m Dominik, the software engineer @ The Best Software Company. We have one big project that have some problems” Dominik The Best Software Company Damian Dziaduch - Reliable communication - PHPers Summit 2023 

The Best Software Company Damian Dziaduch - Reliable communication - PHPers Summit 2023 - Typical company - Huge monolith - Big ball of mud architecture - Features are taking longer and longer - More and more bugs 

“We read few books about micro services, we have decided that we are going fully into micro services.” Dominik The Best Software Company Damian Dziaduch - Reliable communication - PHPers Summit 2023 

Step 3 Network as a spine Step 4 Problems? Step 2 Microservices Damian Dziaduch - Reliable communication - PHPers Summit 2023 The path Step 1 Monolith 

Damian Dziaduch - Reliable communication - PHPers Summit 2023 

“The data is stored and the event is sent. Both must succeed. All or nothing.” Dominik The Best Software Company Damian Dziaduch - Reliable communication - PHPers Summit 2023 

Damian Dziaduch - Reliable communication - PHPers Summit 2023 

Damian Dziaduch - Reliable communication - PHPers Summit 2023 

Damian Dziaduch - Reliable communication - PHPers Summit 2023 

Damian Dziaduch - Reliable communication - PHPers Summit 2023 

Damian Dziaduch - Reliable communication - PHPers Summit 2023 Transactional Outbox 

Damian Dziaduch - Reliable communication - PHPers Summit 2023 Transactional Outbox 

Damian Dziaduch - Reliable communication - PHPers Summit 2023 Transactional Outbox 

＞ Applies to the event producers ＞ Atomicity - all or nothing ＞ Simple command handlers ＞ Sending events is decoupled ＞ Faster command handlers ＞ No event is sent, just stored ＞ Infinite retries ＞ History of sent events Damian Dziaduch - Reliable communication - PHPers Summit 2023 Outbox - benefits 

＞ At least once delivery ＞ Receivers must be ready for this ＞ Inbox pattern for the rescue ＞ A relay is required ＞ Periodically pools events from the outbox ＞ Use log tailing to retrieve events ＞ NoSQL solution is more complex ＞ Complex indexing ＞ Complex querying Damian Dziaduch - Reliable communication - PHPers Summit 2023 Outbox - drawbacks 

＞ Your code is doing critical business logic (core domain) ＞ The event broker is not reliable Damian Dziaduch - Reliable communication - PHPers Summit 2023 Outbox - when to use it 

Damian Dziaduch - Reliable communication - PHPers Summit 2023 Inbox 

＞ Applies only to the event consumers ＞ Event must have unique ID ＞ Event must be stored ＞ They could be stored forever or for some time ＞ Not needed when your application is already idempotent ＞ Product can be created once ＞ Once it is created, next tries will be discarded ＞ History of received events Damian Dziaduch - Reliable communication - PHPers Summit 2023 Inbox summary 

Demo https://github.com/ddziaduch/outbox-pattern Damian Dziaduch - Reliable communication - PHPers Summit 2023 

＞ Outbox ＞ Atomicity - all or nothing ＞ At least once delivery ＞ Infinite retries ＞ History of sent event ＞ Inbox ＞ Guarantees that event is processed only once ＞ History of processed events Damian Dziaduch - Reliable communication - PHPers Summit 2023 Summary 

＞ Remote work ＞ Flexible work day ＞ Stock options ＞ Learning budget ＞ Well-being budget ＞ Paid days off for contractors ＞ MacBooks Damian Dziaduch - Reliable communication - PHPers Summit 2023 We are hiring! jobs.printify.com 

Thank you! Damian Dziaduch - Reliable Communication - PHPers Summit 2023