This is a POC Go program to test some ideas inspired by

• Designing Event Driven Systems by Ben Stopford
• A pratical talk on the subject by Neil Buesing

1. build the go web server and run a couple of instances of each.
2. send them requests, and watch the logs. you will get a uuid for each
3. use a tool like kcat to "respond" to requests

Useful snippets from my shell history

Using kcat to respond:

echo "hello there" | kcat -v -b localhost:9092 -P -t responses -H "request-id=6c50571c-1224-4e2f-baff-ee077c984158"

Using kcat to monitor requests topic:

kcat \
      -b localhost:9092 \
      -t requests-0 -C \
      -f '\nKey (%K bytes): %k
  Value (%S bytes): %s
  Timestamp: %T
  Partition: %p
  Offset: %o
  Headers: %h\n'

The POC works. I haven't benchmarked it but I think I can handle a lot a troughput. Ideally, we would scale the app vertically as much as we can because having multiple copies of the app runnings means each instance will be processing messages meant for other instances.

• To alleviate allocation on the blocker we could use a sync.Pool