Recursive group membership found on an item

[jimtng]

See https://community.openhab.org/t/recursive-group-membership-found/135192

I noticed this on 3.3.0-SNAPSHOT - Build #2852

Error log:

2022-04-16 22:10:20.165 [ERROR] [rest.core.item.EnrichedItemDTOMapper] - Recursive group membership found: BackPorch_Light2 is both, a direct or indirect parent and a child of gOutsideLights.
2022-04-16 22:10:20.166 [ERROR] [rest.core.item.EnrichedItemDTOMapper] - Recursive group membership found: BackPorch_Light1 is both, a direct or indirect parent and a child of gOutsideLights.
2022-04-16 22:10:20.166 [ERROR] [rest.core.item.EnrichedItemDTOMapper] - Recursive group membership found: BackYard_Light is both, a direct or indirect parent and a child of gOutsideLights.
2022-04-16 22:10:20.166 [ERROR] [rest.core.item.EnrichedItemDTOMapper] - Recursive group membership found: BackPorch_Light3 is both, a direct or indirect parent and a child of gOutsideLights.

Items:

Group gLights
Group gOutsideLights  (gLights)

Group:Switch:OR(ON,OFF) gBackYardLights "Backyard Lights" (gOutsideLights) {ga="Light", synonyms="Back Porch Lights, Back Yard Lights"}

Group:Switch:OR(ON,OFF) gBackPorch_Switch2 


Switch             BackPorch_Light2                         "Back Porch Light 2"                                                   <switch>           (gOutsideLights, gBackPorch_Switch2, gBackYardLights, gBackPorch)                                                                      ["Lightbulb"]                      { channel="mqtt:topic:backporch-switch2:power1", autoupdate="false", ga="Light", alexa="Light" }
Switch             BackPorch_Light1                         "Back Porch Light 1"                                                   <switch>           (gBackPorch, gOutsideLights, gBackYardLights, gBackPorch_Switch2)                                                                      ["Lightbulb"]                      { channel="mqtt:topic:backporch-switch2:power2", autoupdate="false", ga="Light", alexa="Light" }
Switch             BackYard_Light                           "Back Porch Light 4"                                                   <switch>           (gBackPorch, gOutsideLights, gBackYardLights, gBackPorch_Switch2)                                                                      ["Lightbulb"]                      { channel="mqtt:topic:backporch-switch2:power3", autoupdate="false", ga="Light" }
Switch             BackPorch_Light3                         "Back Porch Light 3"                                                   <switch>           (gBackPorch, gOutsideLights, gBackYardLights, gBackPorch_Switch2)                                                                      ["Lightbulb"]                      { channel="mqtt:topic:backporch-switch2:power4", autoupdate="false", ga="Light", alexa="Light" }

[jimtng]

Pinging @J-N-K

[J-N-K]

I‘ll provide a fix later today.

[Rossko57]

The underlying trigger here is that the Item (a Switch type) is a direct member of more than one Group in the same hierarchy i.e. a direct member of a 'parent' and a direct member of a 'child'.
I don't think that is anything most people would want to do deliberately - would it make sense to re-word the message for this case, and still report, but as WARN rather than ERROR ?

[J-N-K]

The check was originally implemented to prevent an exception when parsing the data and there is no technical problem in the situation you describe. Are you aware of any negative/unexpected side-effects of this configuration?

[Rossko57]

Well, single commands issued through the 'parent' Group would be sent to the Item twice. openHAB doesn't mind, other stuff might.
Updates of the Item state would cause quite a bit of thrashing about re-calculating Group aggregations. Again, it should all work, but.

I just can't imagine the reason for a user to structure group membership like this by design.