Why are my Morphia Cursors stacking up ?

[tariqanas]

Hello,

I work in a large project , for migrating Morphia from 1.6 to 2.4.11 .
I updated all the DAO to the new versions, but while looking at Grafana , i see that the number of cursors used by this version is greater than the number used by morphia 1.6
I understand that in morphia 1.6 the cursors were handled internally, which is not the case in 2.4.11

Is it a normal behaviour ? we've been analysing this change of numbers but couldn't find an explanation. Is it a normal behaviour ?
We put all the morphia cursors inside a try-with-resource, but we keep seeing them stacking up

Any help or guidance would be much appreciated.

Server Version: 5.0
Driver Version: 4.11
Morphia Version: 2.4

[evanchooly]

I'm not sure i'm following the cursors being handled internally but what do you mean when you cursors stacking up? Do you mean connections to the database?

[evanchooly]

well, 2.0 was a pretty drastic architectural upgrade so there are loads of changes internally for sure. As far as the cursors go, by the time toList() returns Morphia will have already called close() on the cursor so it's up to the driver to manage things from that point.

[tariqanas]

Ok , thank you i'll keep investigating.
To this day , i switched query.iterator(findOptions) to query.stream(findOptions). But still same .
Maybe i should explore other things rather than Morphia.
The Java Mongo driver version seems Ok to you to use with Morphia 2.4.11 ?
Or maybe we should try higher morphia versions like the last one ? 2.4.14 ?

If you don't see anything that can help us , related to Morphia . You may close the discussion .

Thank you V.much Evanchooly.

[evanchooly]

nothing obvious in morphia comes to mind but I don't have a lot of detail to work. there's not really a difference between .11 and .14 so far as this is concerned. If I had to guess, i would say it's likely latency on closing closing sockets or responsiveness on the server responding to cursor closing. Hard to tell from here, though.

[tariqanas]

Hello ,
Just wanted to say that i found what caused the issue .
I had a large query that took time to fetch the data & since it was called many times, with others queries the cursors stacked up on earch others & looked scary .

Beside , i put the cursors in a try with resources to be sure that they were automatically managed.

Things look fine now .
Thank you

[evanchooly]

Oh that's great news. Nice work tracking that down.