Performance issues with lb4 services

[u3ih]

Describe the bug

Using @service or @Inject to inject services can lead to performance issues when calling api (although not using them).

i used autocannon for benchmarking
Full command: autocannon -t12 -c1000 -d30 http://localhost:3000/ping

I tried to inject services into the controller (ping.controller). The more services I import and the larger the project, the more req in seconds decreases

Logs

No response

Additional information

I ran the project on 8 CPUs and tried it multiple times. These are the average results I got.

- Without Injection

I ran the autocannon test and got around 680k requests in 30 seconds.

- With `@service` (around 37 `@service` with the same service file)

I got around 420k requests in 30 seconds.

- With `@inject` (around 37 `@inject` with the same service file)

I got around 600k requests in 30 seconds.

Reproduction

https://github.com/u3ih/loopback-benchmarking

[mathieuBP]

For me, this is to be expected.... Using DI indeed runs more code than not using it. So it is normal that it can slow down a bit. What I find very interesting tough is the fact that @Inject seems way faster than @service which is simply a sugar coated inject...

[u3ih]

I dont think its just 'a bit' with this example its around 30%. And with a big project, it slows down even more 😢