Multi tenant setup support - Supporting connecting to multiple Pulsar instances

[nandorholozsnyak]

Hello there,
I'm working on a project where I want to connect to multiple Pulsar instances and based on what I have found Spring Pulsar "strictly" supports connecting to one Pulsar instance at a time.

I've managed to overwrite the PulsarAutoConfiguration class related beans, but it is a pain to handle them properly, as there are a few inconviniences during the setup like using @Primary and @Fallback beans in case of integration tests.

My "dream" setup would be the following:

spring:
  pulsar:
    tenant-a:
      service-url: pulsar://localhost:6650
    tenant-b:
      service-url: pulsar://localhost:6651
    tenant-c:
      service-url: pulsar://localhost:6652

Right now I create 3 new configuration properties which will create 3 PulsarClient instances, and all the needed dependencies like the:

• DefaultPulsarConsumerFactory
• DefaultPulsarProducerFactory
• ConcurrentPulsarListenerContainerFactory
• PulsarTemplate
  Where the PulsarClients are using the newly created one with the right service Url and authentication if needed.

Is there any better/already provided solution to my problem that would be cool.

[onobc]

👋🏻 @nandorholozsnyak ,

Ahhh yes... the "how do I auto-configure N of the same things w/ Spring Boot" dilemma. Please take a read through an older discussion here. I noticed that my last comment said:

I will take a deeper look and see if I can recommend something a bit softer than the 2 above options.

My bad, as that never happened. I will use this issue as a catalyst for a doc update that provides guidance on this topic (likely put in the ref docs appendix or project wiki).

Thanks,
Chris

[nandorholozsnyak]

Thank you @onobc
I'll share my small code sections because we want to have multiple listeners as well per consumer factories and that's the "hard" part. The Spring pulsar plugin has a lot of package private classes and I had to copy and paste them to make sure the same settings are applied for every connection / consumer / producer factory. 👀