InFlightLongPollingActivateJobsRequestsState#activeRequestsToBeRepeated contains duplicates

[romansmirnov]

Describe the bug

See description in #8310:

Scenario 1: Duplicates in activeRequestsToBeRepeated when other requests succeeds

Given three activate requests x, y, and z:

1. send request z to broker -> current activeRequests = [ z ] and activeRequestsToBeRepeated = [ ]
2. send request y to broker -> current activeRequests = [ z, y ] and activeRequestsToBeRepeated = [ ]
3. send request x to broker -> current activeRequests = [ z, y, x ] and activeRequestsToBeRepeated = [ ]
4. request z completes with at least one activated job -> reset failed attempts -> current activeRequests = [ y, x ] and activeRequestsToBeRepeated = [ y, x ]
5. request y completes with at least one activated job -> reset failed attempts -> current activeRequests = [ x ] and activeRequestsToBeRepeated = [ x, x ]

Scenario 2: Duplicates in activeRequestsToBeRepeated on multiple notifications

Given is a request x:

1. send request x to broker -> current activeRequests = [ x ] and activeRequestsToBeRepeated = [ ]
2. Broker notifies the gateway about new available jobs -> reset failed attempts -> current activeRequests = [ x ] and activeRequestsToBeRepeated = [ x ]
3. Again, Broker notifies the gateway about new available jobs -> reset failed attempts -> current activeRequests = [ x ] and activeRequestsToBeRepeated = [ x, x ]

Scenario 3: Another request wins

Given are requests [z1, z2, z3, ...., zn] and x:

1. send requests [z1, z2, z3, ...., zn] and x -> current activeRequests = [ z1, z2, z3, ...., zn, x ] and activeRequestsToBeRepeated = [ ]`
2. request z1 completes with at least one activated job -> reset failed attempts -> current activeRequests = [ z2, z3, ...., zn, x ] and activeRequestsToBeRepeated = [ z2, z3, ...., zn, x ]
3. request x completes without any jobs -> retry request -> current activeRequests = [ z2, z3, ...., zn, x ] and activeRequestsToBeRepeated = [ z2, z3, ...., zn ]
4. request z2 completes with at least one activated job -> reset failed attempts -> current activeRequests = [ z3, ...., zn, x ] and activeRequestsToBeRepeated = [ z3, ...., zn, x ]
5. request x completes without any jobs -> retry request -> current activeRequests = [ z3, ...., zn, x ] and activeRequestsToBeRepeated = [ z2, z3, ...., zn ]
6. ...

In all scenarios, the queue activeRequestsToBeRepeated contains the request x at least once before the response arrives. In a nutshell, as long as the failed attempts are lower than the configured threshold and the request x is present in the queue of repeatable requests, the request x is executed in a loop when it responds with any activated job.

Expected behavior

• InFlightLongPollingActivateJobsRequestsState#activeRequestsToBeRepeated does not contain duplicates

Environment:

• Zeebe Version: 1.2.5
• Configuration: Enabled Long Polling

---

is depended on by #8310

[romansmirnov]

Moving back to the Ready column because I am currently not actively working on it.