Ruuter mixing up responses when multiple requests in parallel using conditions

[turnerrainer]

Important

In case of running multiple simultaneous threads on Ruuter, responses to requests get mixed up at some point

Acceptance Criteria

• Detect Ruuter functionalities that mix up responses #325
• Remove functional programming from Ruuter's Java code #326
• The linked discussion that is the base of this is issue can be closed due to being resolved

Discussed in #133

^{Originally posted by gdrui February 3, 2023}
Given an endpoint that fetches different data from Resql based on the provided parameters:

extract_request_data:
  assign:
    requestedMetric: ${incoming.params.metric}

checkMetric:
  switch:
    - condition: ${requestedMetric === 'total_chats_day'}
      next: getTotalChatsDayResults
    - condition: ${requestedMetric === 'total_chats_month'}
      next: getTotalChatsMonthResults
    - condition: ${requestedMetric === 'total_chats_no_csa_day'}
      next: getTotalChatsNoCSAResults
    - condition: ${requestedMetric === 'avg_chats_by_month'}
      next: getAvgChatsMonthResults
    - condition: ${requestedMetric === 'avg_chats_by_week'}
      next: getAvgChatsWeekResults
    - condition: ${requestedMetric === 'avg_chats_no_csa_by_month'}
      next: getAvgChatsNoCSAMonthResult
    - condition: ${requestedMetric === 'avg_chats_no_csa_by_week'}
      next: getAvgChatsNoCSAWeekResult
    - condition: ${requestedMetric === 'avg_waiting_time_day'}
      next: getAvgWaitingTimeDayResult
    - condition: ${requestedMetric === 'avg_waiting_time_week'}
      next: getAvgWaitingTimeWeekResult
    - condition: ${requestedMetric === 'total_forwarded_chats_yesterday'}
      next: getTotalForwardedChatsResult
    - condition: ${requestedMetric === 'chat-activity'}
      next: getChatActivityResult
  next: invalidMetric

If this endpoint is called once with any valid parameter it will return the correct result.
However if many or all of these options are called in parallel requests then sometimes the results get mixed up and for example I can receive the result of avg_waiting_time_day when the request was with the parameter total_chats_day

I also tried to replace the individual steps so that instead of an asynchronous http.post step each step would only return a unique value like :

getTotalChatsDayResults:
  return: 'A'
  next: end
  
getTotalChatsMonthResults:
  return: 'B'
  next: end
...

This seems to happen less frequently like this, but I still observe the same thing happening:

When its OK:

When its not OK: