Hopsworks REST api for maggy expects that maggy registers itself only once with a certain app_id.
But when multiple experiments are started from the same app, maggy registered itself everytime with a different and hence the REST api failed to return the maggy server address to sparkmagic since it finds multiple matching entries to the app_id in the database.
Now maggy registers only once and reuses hostort and secret token for multiple experiments within same app (Maggy version 0.2.2).
However, this introduced a new problem when a second experiment is run from same app, because sparkmagic gets the address of the maggy server from Hopsworks before the server is ready to accept connections.
This is resolved by having sparkmagic try to connect to maggy 10 times, if it does not succeed the user is notified by a print that there is no progress/logs available. Generally, this is enough time for maggy to start, the warning is mainly for cases when the user uses an old maggy version.