Calls not removed from memory even after completing

[maria-farooq]

Problem
we recently found that RC was pilling up Call and MMSCallController actors in memory. we could see that Call was in stopping state and MMSCallController was in inactive state.

Root Cause

• Calls were related to Recording here is what happens to them:
• RC received BYE.
• Call goes to Stopping state.
• Call send msg to MMSCallController to clean MediaServer resources.
• MMSCallController clean MS resources and give back proper response (INACTIVE).
• Call moved to Completed state & DB was updated properly.
• At VoiceInterpreter, RCML kicks in and sends Hangup to the call (please mind call was already completed)
• upon receiving Hangup, Call moves from Completed to Stopping state AGAIN
• and send msg to MMSCallController to clean MediaServer resources AGAIN. (please mind MMSCallControllerwas already INACTIVE)
• MMSCallController has not defined action for this situation hence does nothing
• Call keeps waiting for response from MMSCallController hence actor stays in memory forever.

Comments & Questions

• If a Call is already Completed and we get a Hangup, should not we ignore it..
• should a transition from Completed to Stopping state be allowed? wHy?

Reference:

• ZD
• code ref 1
• code ref 2

[gvagenas]

When Call actor will receive BYE, will from Stopping to Complete state (after receive MmsCallController response) and will notify VoiceInterpreter for the new state.
When VoiceInterpreter receive the Completed state change, will:

1. Ask Call actor to stop media group

2. Will move to finishRecording

3. Call actor will receive StopMediaGroup but will do nothing since the state is NOT if (is(inProgress) || is(waitingForAnswer)) {

4. VI state finishRecording will wrapup the recording and will either stop the interpreter or get next verb.

There is a race condition at step 2 where VI might never proceed to the next step and hang there forever and that seems to be the issue here

[gvagenas]

When the race condition described at previous comment doesn't occur, VI gets End RCML tag and sends Hangup on the call as @maria-farooq describes in her comment
So actually 2 issues here