GreengrassV2-Core's IoT-Thing-shadow never beeing synchronized with remote

Hi,

I successfully deployed a custom python component on a greengrassv2-core-device. When updating the local device shadow successfully (as the log says) using aws-iot-device-sdk-python-v2, it basically never shows up in the AWS console.

Setup

• The core device is online.

• This is the component-code I'm updating the local shadow with:

THING_NAME = "thingname"
SHADOW_NAME = "shadowname"
last_heartbeat = ...

shadow = {
    "state": {
            "reported": {
                "last_heartbeat": last_heartbeat,
            ...
        }
    }
}

try:
    # create the UpdateThingShadow request
    update_thing_shadow_request = UpdateThingShadowRequest()
    update_thing_shadow_request.thing_name = THING_NAME
    update_thing_shadow_request.shadow_name = SHADOW_NAME
    update_thing_shadow_request.payload = json.dumps(shadow).encode('utf-8')

    # retrieve the UpdateThingShadow response
    op = ipc_client.new_update_thing_shadow()
    op.activate(update_thing_shadow_request)
    fut = op.get_response()

    result = fut.result(5)
    return result.payload

except InvalidArgumentsError as e:
    print("InvalidArgumentsError: %s", e.message)
except ConflictError as e:
    print("ConflictError: %s", e.message)
except UnauthorizedError as e:
    print("UnauthorizedError: %s", e.message)
except ServiceError as e:
    print("ServiceError: %s", e.message)

• My ShadowManager configuration:

{
   "reset":[
      
   ],
   "merge":{
      "reset":[
         
      ],
      "merge":{
         "strategy":{
            "type":"periodic",
            "delay":300
         },
         "synchronize":{
            "coreThing":{
               "classic":false,
               "namedShadows":[
                  "shadowname"
               ]
            },
            "direction":"betweenDeviceAndCloud"
         },
         "rateLimits":{
            "maxOutboundSyncUpdatesPerSecond":100,
            "maxTotalLocalRequestsRate":200,
            "maxLocalRequestsPerSecondPerThing":20
         },
         "shadowDocumentSizeLimitBytes":8192
      }
   }
}

Observations

Based on the positive greengrass-core log underneath, I ommit the component-recipe and iot-thing-policy, but these are configured with with permissions to update a shadow.

When executing the codesnippet I get these entries in <GREENGRASSV2_DIR>/log/greengrass.log (there are multiple success-entries, this is just one):

2022-08-03T21:19:26.177Z [INFO] (Thread-27) com.aws.greengrass.shadowmanager.ipc.UpdateThingShadowRequestHandler: Successfully updated shadow. {service-name=componentname, thing name=thingname, shadow name=shadowname, local-version=9}

So everything seems to be fine so far, my component keeps happily updating its local shadow. For some reason the local shadow is never beeing synchronized with remote (when having a look in console there are no shadows for the IoT-Thing) although the ShadowManager is configured properly.

Questions

• Why isn't the shadow beeing synchronized?
• Do I have to create the Thing-shadow manually before its starting to synchronize (even though it need to be timed properly when using cloud provisioning with a IoT-Thing-group)?
• Did I miss something which prevents the shadow from beeing synchronized?

Relevant doc-links

• Configure ShadowManager for Sync
• Sync local Shadows