GET /api/gateways/{gateway_id}/pings/last - Object does not exist

ChirpStack Application Server
1

I am getting the below when using valid Gateway IDs on the GET /api/gateways/{gateway_id}/pings/last API.

{
“error”: “object does not exist”,
“message”: “object does not exist”,
“code”: 5,
“details”: []
}

I am able to GET using api/gateways without any issue. I have tried with multiple Gateway IDs which have been returned using the api/gateways. Just for clarity I have been using single Gateway IDs e.g. c0ee40ffff294cf5

Has anyone seen this before or have I missed something obvious?

2

The gateway may exist, but last ping may not. This is the function that tries to retrieve the last ping:

func GetLastGatewayPingAndRX(db sqlx.Queryer, mac lorawan.EUI64) (GatewayPing, []GatewayPingRX, error) {
	gw, err := GetGateway(db, mac, false)
	if err != nil {
		return GatewayPing{}, nil, errors.Wrap(err, "get gateway error")
	}

	if gw.LastPingID == nil {
		return GatewayPing{}, nil, ErrDoesNotExist
	}

	ping, err := GetGatewayPing(db, *gw.LastPingID)
	if err != nil {
		return GatewayPing{}, nil, errors.Wrap(err, "get gateway ping error")
	}

	rx, err := GetGatewayPingRXForPingID(db, ping.ID)
	if err != nil {
		return GatewayPing{}, nil, errors.Wrap(err, "get gateway ping rx for ping id error")
	}

	return ping, rx, nil
}

In particular, this part returns “object does not exist” when there’s no ping:

if gw.LastPingID == nil {
	return GatewayPing{}, nil, ErrDoesNotExist
}

So check your DB to be sure?

3

Thanks for your reply - I am assuming that ‘last seen’ time in the main application server portal is pulling the last ping time? In the portal all the Gateway IDs I have been testing have been seen in ‘a few seconds ago’

I am trying to pull the ‘last seen’ for each Gateway into a clients Portal. Maybe this is the wrong way to be doing it?

4

The ping you are trying to get isn’t related to gateway stats, is related to gateway discovery. On the other hand, just getting a gateway will give you a lastSeenAt with the response, while /api/gateways/{gateway_id}/stats lets you retrieve stats.

5

Thank you @iegomez - is there an API I can get the ‘lastSeeAt’ value from? I have been looking and can’t seem to find it!

6

Forget that last message - I have got it sorted. I misread what you had said. Many Thanks.

2 Likes