Build Cloud-Native apps with Apache Cassandra

GOT QUESTIONS from the Workshop? You're in the right place! Post a question here and we'll get you answers.

Click here for Week 8 Materials and Homework.

Follow us on Eventbrite to get notified when new workshops are scheduled!


question

David Jones-Gilardi avatar image
David Jones-Gilardi asked ·

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
10 |1000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 1.0 MiB each and 10.0 MiB total.

1 Answer

bettina.swynnerton avatar image
bettina.swynnerton answered ·

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!

3 comments Share
10 |1000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 1.0 MiB each and 10.0 MiB total.

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]

0 Likes 0 · ·

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

2 Likes 2 · ·

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!

0 Likes 0 · ·