how to block in reactor

...when it's needed

problem

In short: we should never block! But sometimes we just cannot avoid blocking calls... For instance, when we have to use library which hasn't reactive non-blocking support, and maybe even not planed to be reactive, legacy libraries, JDBC, ThreadLocal, etc...

identify problem

• use reactor-tools
• use BlockHound

solve problem

• bad: create separate microservice, which will call blocking one
• good: perform all blocking calls in a separate thread provided by special defined scheduled

run and test

1. start apps:

   jdk11 ; ./mvnw -f mongo spring-boot:run
   jdk11 ; ./mvnw -f name-service spring-boot:run

2. execute all REST API calls from api.http file

resources

• YouTube: Avoiding Reactor Meltdown