Hi Jakob, I haven't developed the tutorial, mine was just a wild guess :) answers to your questions (to the best of my knowledge) inline: On Wed, 9 Mar 2022 at 14:31, Jakob Schnell <Jakob.Schnell at heigit.org> wrote: > Hey Federico, > > thanks for your reply. > I am indeed referring to the tutorial you linked to. > > Sorry for not clarifying this in my initial question - I noted that docker > volumes were being removed, so I commented out Lines 56 through 60 in the > services script. They are now not removed anymore, so the CrateDB-Data is > still > available after a restart. > > However, even after using > docker-compose down > docker-compose up > as you suggested, the created subscriptions don't exist anymore. > > THus, all my initial questions remain: > * Can I persist subscriptions or do I have to recreate them on a system > restart? > They are supposed to be persisted in mongo, like any other data passed to orion. > * Can I get QuantumLeap or Orion to return the data saved in the CrateDB > after > a restart? > If data is persisted (i.e. volumes of mongo and crate are not removed), you can use QL to query timeseries (historical data), and Orion to query last data received. > * What exactly is the purpose of the MongoDB connected to Orion? > provides the persistency to any data received by orion > * What is the purpose of the Redis connected to QuantumLeap? > provides caching to improve performance. Cheers, Federico > > Best regards, > Jakob > > On Wed, 9 Mar 2022 14:09:32 +0100 > Federico Michele Facca <federico.facca at martel-innovate.com> wrote: > > > Hi Jakob, > > I suppose you are referring to this tutorial: > > https://github.com/FIWARE/tutorials.Time-Series-Data > > > > Looking at the docker compose, volumes are there, so data should be > > persisted, unless when when you > > stopped docker compose, you also removed the volumes (e.g. docker-compose > > down -v). > > > > Which is exactly what the stoppingContainers() function of the services > > script does: > > > https://github.com/FIWARE/tutorials.Time-Series-Data/blob/master/services#L50 > > > > As indeed also explained in the documentation: > > [image: image.png] > > > > Bottomline, if you re-run the tutorial, but instead of cleaning up you > just > > stop and restart the docker-compose stack, > > data will be there, e.g. > > > > docker-compose down > > > > docker-compose up > > > > Cheers, > > > > *Dr. FEDERICO MICHELE FACCA* > > *CTO, Head of Martel Lab* > > +41 788075838 > > *MARTEL INNOVATE* <https://www.martel-innovate.com/> - INNOVATION, WE > MAKE > > IT HAPPEN > > Click *HERE* to download Martel reports and white papers! > > <https://www.martel-innovate.com/premium-content/> > > Follow us on *TWITTER* <https://twitter.com/Martel_Innovate> > > > > > > On Wed, 9 Mar 2022 at 12:19, Jakob Schnell <Jakob.Schnell at heigit.org> > wrote: > > > > > Hey, > > > > > > I'm currently setting up a FIWARE backend using docker, following the > > > "Querying Time Series Data" tutorial. I am a bit confused by how the > FIWARE > > > components are supposed to behave on a restart of the system. > > > > > > My setup consists of a Context Broker (Orion), QuantumLeap and a > CrateDB > > > for > > > data persistence, and I have created subscriptions for possible > incoming > > > data. Assume that some data has been entered and persisted into > CrateDB. > > > > > > If I now restart the running docker containers, if I understood > correctly, > > > Orion won't have any data anymore, the subscriptions will be gone and I > > > haven't > > > found a way to get QuantumLeap to query the CrateDB for the data > entered. > > > > > > That would mean that I have to create all subscriptions anew and that I > > > have to > > > query CrateDB directly for any "historical" data, which makes the > system > > > rather > > > clunky to use. All restarts would require manual interaction or some > sort > > > of > > > automating the creation of subscriptions, and all advantages of > NGSI-v2 are > > > lost if CrateDB has to be queried directly. > > > > > > Is there a way to persist subscriptions? Can I get QuantumLeap or > Orion to > > > return the data saved in the CrateDB? > > > > > > On a related note, could you explain what the purpose of the MongoDB > > > connected > > > to Orion and the Redis connected to QuantumLeap is? Would the system > work > > > without either of these? > > > > > > Thanks for your help, > > > Best regards, > > > Jakob Schnell > > > > > > -- > > > Jakob Schnell > > > HeiGIT gGmbH > > > Heidelberg Institute for Geoinformation Technology at Heidelberg > University > > > > > > https://heigit.org | jakob.schnell at heigit.org | phone +49-6221-533 482 > > > > > > Postal address: Schloss-Wolfsbrunnenweg 33 | 69118 Heidelberg | Germany > > > Offices: Berliner Str. 45 | 69120 Heidelberg | Germany > > > > > > Amtsgericht Mannheim | HRB 733765 > > > Managing Directors: Prof. Dr. Alexander Zipf | Dr. Gesa Schönberger > > > > > > > > > > > > > __________________________________________________________________________________________ > > > > > > You can get more information about our cookies and privacy policies on > the > > > following links: > > > - > > > > https://fiware-legal.readthedocs.io/en/latest/PersonalDataProtectionPolicy.html > > > - > https://fiware-legal.readthedocs.io/en/latest/FIWARECookiesPolicy.html > > > > > > > > > fiware-tech-help mailing list > > > fiware-tech-help at lists.fiware.org > > > > > > To unsubscribe from fiware-tech-help mailing list, go to the > information > > > page of the list at: > > > https://lists.fiware.org/listinfo/fiware-tech-help > > > > > > > > > > -- > Jakob Schnell > HeiGIT gGmbH > Heidelberg Institute for Geoinformation Technology at Heidelberg University > > https://heigit.org | jakob.schnell at heigit.org | phone +49-6221-533 482 > > Postal address: Schloss-Wolfsbrunnenweg 33 | 69118 Heidelberg | Germany > Offices: Berliner Str. 45 | 69120 Heidelberg | Germany > > Amtsgericht Mannheim | HRB 733765 > Managing Directors: Prof. Dr. Alexander Zipf | Dr. Gesa Schönberger > > > -------------- next part -------------- An HTML attachment was scrubbed... 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