Reliable reply from vessel-location-controller : Vessel Location Controller ?

[Brian Bach Mortensen]

Hi

Over the past week I have tried to work with the vessel location controller at: https://meri.digitraffic.fi/api/v1/metadata/documentation/swagger-ui.html#!/vessel45location45controller/vesselLocationsByTimestampUsingGET

However it occurs to me that the interface is quite unreliable, i.e. half of the time I dont get a reply with any vessel data. Is this a common problem or is it because I am doing something wrong?? See a request I just ran below:

epoch time in miliseconds: 1517816467881

epoch time minus 1 minute in miliseconds: 1517816407881

search string: https://meri.digitraffic.fi/api/v1/locations/latest?from=1517816407881&to=1517816467881

number of mmsi: 0

unique mmsi: 0

Making the "from" time smaller, e.g. subtracting more time doesn't really change anything.

Is there a service status information page somewhere to check that everything is alright?

Best regards

   Brian 

[Solita / Ville]

Hi,

Vessel location data stream is broken at the moment. We are investigating the problem.

You can use status.digitraffic.fi monitoring service to see the status of the API.

Sorry for any inconvenience caused.

Ystävällisin terveisin / Best regards

– Digitraffic asiakastuki / Digitraffic support  –

[Solita Teijo]

Hi

Service is back to normal again.  Sorry for any inconvenience.

Ystävällisin terveisin / Best regards

– Digitraffic asiakastuki / Digitraffic support  –

[Brian Bach Mortensen]

Hi

Thank for the update and the information - was going nuts over this :D

Best regards

   Brian

[Brian Bach Mortensen]

HI Again

Not sure if there is a problem again. The status page says green, but when I try to load data for the last minute I get nothing. I noticed however that without specifying the from and to fields I get around 5600 vessel positions.. However, calculating their age in seconds and sorting them reveals that data are all older than 90 seconds (See my script readout further below). Other runs gave a lower delay readout. I dont think the interface is supposed to work like this? Is this due to internal server overload on your side, I have seen similar on our systems (new data getting backlogged before being written to the our database)?

Best regards

   Brian Bach Mortensen

unique mmsi: 5649

91.091

91.091

91.093

91.093

91.096

91.097

91.098

91.1

91.1

91.103

91.104

91.107

91.108

91.109

91.11

91.11

91.112

91.114

91.117

91.118

91.118

91.119

91.121

91.128

91.13

91.13

91.131

91.132

91.133

91.134

91.137

91.141

91.142

91.143

91.144

91.145

91.667

91.668

91.668

91.671

91.673

91.674

91.676

91.676

91.678

91.679

91.68

91.682

91.683

91.684

91.685

91.686

91.688

91.689

91.693

91.698

91.7

91.71

91.714

91.719

91.719

91.72

91.722

91.723

91.724

91.725

91.725

91.726

91.729

91.732

91.733

91.735

91.736

91.738

91.739

91.741

91.742

91.744

91.748

91.749

91.752

91.756

91.756

91.757

91.758

91.761

91.763

91.764

91.765

91.767

91.768

91.771

91.772

91.775

91.776

91.777

91.778

91.778

..

31240162.127

31256330.834

31286610.492

31288892.926

31292891.447

31295006.307

31357748.643

31370887.318

31463376.613

31466776.468

31508207.308

31598891.349

31692346.416

31713632.396

31715397.765

31753156.868

Process finished with exit code 0

[Tuomas Leikola]

I've seen this before as well, altough it was a lot longer than 90 seconds. I'd expect it's a backlog buildup issue just like you described.

[Solita Teijo]

Hi

Thanks for the info.  We will look into this.

Ystävällisin terveisin / Best regards

– Digitraffic asiakastuki / Digitraffic support  –

[Solita Teijo]

Hello again

If you are using the rest-api, the responses are cached.  For example:

https://meri.digitraffic.fi/api/v1/locations/latest/230994880

So, you cannot get real time feed from there.  If you need real-time feed, you should use websockets.  You can read more here(currently only available in finnish).  You can find a trivial example written in javascript there.

http://digitraffic.liikennevirasto.fi/meriliikenne/#websocket-rajapinnat

Ystävällisin terveisin / Best regards

– Digitraffic asiakastuki / Digitraffic support  –

[Tuomas Leikola]

To clarify my experience, it was something like half an hour's lag, i don't remember exact details any more..

When i did a query with time parameter five minutes from now(), it resulted nothing. When i did a longer timelimit query, it responded with most vessels lagging said half an hour. When doing that same query repeatedly, the vessels' timestamps did increase as expected, but stayed ~ half an hour old.

This was when we stopped looking into the rest api and are using websocket now. However i have not monitored if it also sends delayed data sometimes. 

[Solita Teijo]

Thanks for the additional information.  This is probably due lag in the system that we integrate to.  We will add measuring to better address this problem.

Ystävällisin terveisin / Best regards

– Digitraffic asiakastuki / Digitraffic support  –