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  1. Data Management
  2. DM-19581

ack accumulation on SALPY + SalObj



    • Type: Bug
    • Status: Won't Fix
    • Resolution: Done
    • Fix Version/s: None
    • Component/s: None
    • Labels:
    • Team:
      Telescope and Site


      While testing the ATPtg with the ATMCS (DM-19541) I noticed that, after leaving tracking for a while, commands against ATMCS would take a long time to be acknowledged. After debugging it for some time I figured that the issue is a combination of how acknowledgements are handle by SAL and SalObj. Basically, for each component there is a single ackcmd topic. So, all commands for a single component share the same topic for acknowledging a command. So, assume there are three components C1, C2 and C3.

      C1 has a remote* for C2 and C3
      C2 is a controller* that has a remote for C3
      C3 is a controller with no remotes.

      when C1 sends a command to C2, C2 will start to stream commands to C3. The acknowledgment sent by C3 for each command it receives is queued by C1. If C1 need to send a command to C3, it will have to check all the queued acks before arriving at the intended one (probably the last one in the queue).

      To fix this C1 could be continuously checking for acks on salobj level. The dds version of salobj is already implemented to do so. We should consider doing the same for salpy version of salobj.

      *remote = sends commands and listens for telemetry and events.
      *controller = listen for commands and sends telemetry and events


          Issue Links


            tribeiro Tiago Ribeiro created issue -
            tribeiro Tiago Ribeiro made changes -
            Field Original Value New Value
            Link This issue relates to DM-19579 [ DM-19579 ]
            rowen Russell Owen made changes -
            Link This issue is blocked by DM-19579 [ DM-19579 ]
            rowen Russell Owen made changes -
            Link This issue relates to DM-19579 [ DM-19579 ]
            swinbank John Swinbank made changes -
            Team Telescope and Site [ 13500 ]
            tribeiro Tiago Ribeiro made changes -
            Resolution Done [ 10000 ]
            Status To Do [ 10001 ] Won't Fix [ 10405 ]


              tribeiro Tiago Ribeiro
              tribeiro Tiago Ribeiro
              Russell Owen
              Andy Clements, Dave Mills, James Buffill [X] (Inactive), Russell Owen, Tiago Ribeiro
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