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David Jones-Gilardi avatar image
David Jones-Gilardi asked Erick Ramirez commented

Can system_view.clients be used to monitor node connectivity?

Per a question from @navjyotnishant

"Question regarding virtual tables, specifically system_view.clients. Can this be considered as a table to monitor connection to a node at runtime? Something similar to session monitoring in usual RDBMS?"
cassandramonitoring
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bettina.swynnerton avatar image
bettina.swynnerton answered Erick Ramirez commented

Hi,

yes, the clients virtual tables will list all connected clients, with information such as the number of issued requests or what username it is using.

Virtual tables will be introduced with Cassandra 4.0.

Here is a great blog about the new tables:

https://thelastpickle.com/blog/2019/03/08/virtual-tables-in-cassandra-4_0.html

Virtual tables are already in the version that underpins Astra, however the database permissions are insufficient to view these tables.

KVUser@cqlsh:system_views> select * from system_views.clients ;
Unauthorized: Error from server: code=2100 [Unauthorized] message="User KVUser has no SELECT permission on <table system_views.clients> or any of its parents"

I hope this helps!

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navjyotnishant avatar image navjyotnishant commented ·

Thats great. I am looking forward to have this feature released which will solve long due session monitoring problem for cassandra.

[Follow up logged as question #6113]

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bettina.swynnerton avatar image bettina.swynnerton ♦♦ navjyotnishant commented ·

it's a new feature, I'll have to research how this is implemented, will get back to you :)

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Erick Ramirez avatar image Erick Ramirez ♦♦ navjyotnishant commented ·

To close the loop, I've responded to the follow-up question #6113 with details of how to take advantage of the client connection statistics introduced by virtual tables. Cheers!

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