Major Description
Investigate and fix: no cursor returned when getting incoming connections?
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From Andrew Lane on the user mailing list:
Let's say I have some collection called someentity that has connections to other entities via a verb subscribedto. For a particular entity with id some_id, I'd like to pull all the entities that are connected to this entity via the subscribedto verb. I can do that via this GET request:
/org/app/someentity/some_id/subscribedto
However, I'm not sure how I stream or page through this data if there are thousands or more results. I'm not getting back a cursor or anything. Is having a huge number of connections to a particular entity something that's just not a smart thing to do with Usergrid?
From Dave Johnson:
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Usergrid is designed to support a huge number of connections, and we implemented "edge sharding" to ensure that we are not thwarted by Cassandra's 2-billion column limitation.
The normal way to page through results is to have a cursor, so the fact that you did not get a cursor is a problem, and most likely a bug – can you share the exact API call you are making as a curl (or HTTPie) command? Do you see any errors in the logs?
From Andrew Lane:
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I have a collection of events, and users can subscribe to those events via a connection called "subscribedto". For a particular event (some_event_id), I'm trying to stream all the users that are subscribed to that event. In my scenario, there are over 1000 subscribers. I'm issuing something like this (note the "connecting" part of the URL, which I accidentally ommitted previously):
curl -X GET "http://myserver:8080/myorg/sandbox/events/some_event_id/connecting/subscribedto?limit=5"
It's correctly limiting to 5 users, but I'm not getting any cursor where I can continue streaming. If I remove the limit clause, I only get the first 1000 results, which I expect. But again, no cursor to continue to pull data.
From Andrew Lane:
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I should be clear that I DO get a cursor when querying the relationship in the opposite direction. That is, if a single user is subscribed to more than 1 event, I can stream those successfully and I get a cursor. It's the inverse direction that's not giving me a cursor.