OpenCPN 5.6.2 - SignalK connection causes freeze

[mhember]

Hi,

I'm using a signalK server which has GPS, wind, log, compass, AIS, and a range of other boat data integrated. Since OpenCPN now has a signalk network connection capability on my chartplotter (client) machine (Pi) I've tried using the signalk connection.

This autodiscovers fine, and works ok however openCPN freezes frequently with no error message and has to be 'killed' and restarted. When I use a network NMEA0183 connection to Signal K using port 10110 everything is fine.

Is there anything I should consider? Does the signalk stream need to be rate limited or filtered some how? The signalk server already has it's input data connections setup to filter multiple sources (eg GPS position from the receiver and the AIS are prioritised with the timeout function).

Happy to send backtrace etc if useful.

Using 5.6.2 on an 8Gb Pi 4.

Thanks in advance - love OpenCPN and use it a lot.

Marcus

[bdbcat]

Marcus...
Is the trouble related to autodiscover? That is, if you disable autodiscover, and select the source IP address and port manually, how does it perform?


Dave

[mhember]

Hi Dave,

Not sure but I'll give that a go and get back to you.

Marcus

[mhember]

Hi Dave,

Automatic discovery turned off and IP etc entered directly - I'm afraid the results are the same.

Normally crashes within 10-15 minutes, freezes with no error message and becomes unresponsive.

I've switched back to NMEA, but let me know if there is anything else I should try out.

Thanks again,

Marcus

[bdbcat]

Marcus...


I'm not following this, from your previous post:
"When I use a network NMEA0183 connection to Signal K using port 10110 everything is fine."


What then is "not fine"?


Dave

[mhember]

Hi Dave,

I think I should be able to use the 'native' signalk protocol connection to the server rather than signalk's (reduced) nmea0183 protocol output network connection? I don't get AIS tracks for one thing over the NMEA 0183 network connection which I do over the signalk connection.

Ideally to reduce overhead I'd like to be able to turn off the nmea0183 stream and just use the signalk connection on port 3000.

The bottom line - when I use the signalk protocol option to connect to the server opencpn freezes consistently after a few minutes.

Am I making any sense at all - sorry!

Marcus

[bdbcat]

Marcus...
I guess we need to know more about the signalK server in use. Homebrew? Or...?


Dave

[mhember]

Hi Dave,

It is an openplotter installation, although I don't really use the 'openplotter' aspects of it but keep the vanilla SignalK installation updated using the built-in signal k appstore mechanism.

Running version 1.43.0 on a Pi.

Has some NMEA0183 serial feeds and an NMEA2000 feed, along with some remote sigsense devices (engine, tanks, etc) but nothing that should input to opencpn.

Do you need any more? backtrace etc?

Marcus

[bdbcat]

Marcus....
I do not know how practical this would be, but...
If you could record a signalK stream that reliably causes OCPN client to hang, then this would be very useful.
But I'm probably asking for a unicorn...
In your experience, is there any element of repeatability seen?
Any possibility of making your sK server internet accessible, so that I made attach to it and do some debug?


Dave

[mhember]

Hi Dave,

I'm afraid I've not been able to detect a pattern but will keep trying. We are sailing at the moment so a bit hard to put it into a state where it will crash too much.

I am happy to make the signalk server accessible over the internet - although we are on our way to the Outer Hebrides so connectivity might be patchy. A few ways of doing this:
- I think I could setup an SSH tunnel to a land-based server for you to access.
- Using one of the cloud plugins on SignalK (signalk-cloud) which might be easier?

I'll get on with the second option and see how I get on.

Thanks for taking the time to look at this.

Yours aye

Marcus

[mhember]

Hi Dave,

I've managed to connect to the signalk cloud server; cloud.signalk.org.
If I go to data browser, and set the context to vessel:urn:mrn:imo:mmsi:235013716 I now see all of my boat's signalk data. Does that help? Can you stream from that?

Arrived at our destination and should have a stable 4G connection for the next couple of days.....

In terms of making a port directly accessible on my server, I don't think the 4G stick I'm using supports an open external port so it would need to be an ssh tunnel. Happy to do that if the signalk cloud option no good.

Marcus

[jongough]

I have just come across the same issue with freezing when using the signalk tcp:3000 port input. Using NMEA0183 does not freeze, but does 'lose' data at times, i.e. HDM from the autopilot is only seen for a little while then stops.


Last time I used this process on the previous version of OCPN, 5.2.4 it worked fine with signalk 1.37.5. It appears to be an issue with 5.6.2 and signalk 1.42.0 on my Pi 3B+ with ubuntu buster (openplotter 2.9.x).


It seems to be to do with processing the data stream as when it is working correctly the OCPN UI is responsive, but the CPU goes to 100% of one processor and the only option is to kill OCPN. It looks like there is a loop or timing issue in the processing of the signalk data stream.


There is no indication in opencpn.log, it just stops, ubuntu system journal, all appears OK, signalk keeps on going and reports no errors. So apart from the lockup there are no other external symptoms.


The lockups don't appear to happen when the system is started but the devices are turned off, i.e. no AIS/GPS data, but turn these on an it locks up within seconds.

[bdbcat]

Jon...
If the system freezes "within seconds" with live data, it should be possible to capture a reasonably sized stream of sK data. Then it should be laboratory reproducible.
Possible?
Thanks
Dave

[mhember]

Dave,
Is my cloud connection any use to you? If not I'll turn off as it is a bit of a bandwidth hog.

I'm very happy to try and capture a bit of data stream for you if you can suggest the best method to use I'll do so.

Jon - thanks for chipping in, glad it is not just me!

Thanks

Marcus

[bdbcat]

Marcus...
Unfortunately, the sK cloud connection will not help.
But thanks for trying.
Dave