Asking this same question again Vertx event bus slow consuming issue
We have a non clustered vertx application, and we use the event bus to internally communicate between verticles.
- Verticle A consumes from the bus, performs a HTTP request, and sends the response back through the bus.
- Verticle B just request to perform that HTTP request.
The problem appears when a "high" request volume is performed by Verticle B. Then, the consumer starts receiving the events slower and slower (presumably because they are getting queued in the event bus). For 8 requests/second the bus takes up to 3-4 seconds to consume the event. When the requests/second are elevated, it can take more than 30 seconds to consume it, so the bus timeout is triggered.
The thing is, Verticle A is really fast performing the HTTP operation (~200ms) so I don't really understand why the requests get stuck in the bus.
We've tried many solutions but none ot then worked:
- Deploy multiple instances of Verticle A as workers
- Use vertx.executeBlocking() to perform the HTTP request
The only thing that worked was commenting the HTTP request and returning a mock object through the bus. But again, the HTTP request doesn't take more than 200ms, so it shouldn't be blocking the bus.