Re: Local read request going across DC

[Erick Ramirez]

Would you be open to temporarily posting the full CQL command + full trace
output to gist.github.com? I'd like to see what it shows. Cheers!

>

Re: Local read request going across DC

[Raphael Mazelier]

I lost the beginning of the thread but I raised what seems the same 
issue recently in this list.


I have a worldwide c* cluster with 3dcs (eu, us, ap 8nodes each). For 
whatever reason I have read with consistency set to local_quorum which 
trigger reads on other dc(s). I would say it's 1% of the queries. 
read_repair is set to 0. I follow this thread with interest. C* version 
is 3.11.4.


--
Raphael Mazelier

On 21/09/2022 09:23, Erick Ramirez wrote:
Would you be open to temporarily posting the full CQL command + full 
trace output to gist.github.com ? I'd like to 
see what it shows. Cheers!

Re: Local read request going across DC

[Erick Ramirez]

Just to circle back here, I've reviewed the trace output and it shows
multiple requests fired off for lookups on the `roles` table which
indicated to me that the default `cassandra` superuser is being used. To be
clear, the original read request is being executed at the configured
consistency BUT authenticating with the default `cassandra` superuser
requires `QUORUM` so it spans across DCs.

For this reason, we recommend that the default `cassandra` superuser only
be used for provisioning a new admin role then should not be used again.
Cheers!

>

Re: Local read request going across DC

[manish khandelwal]

Thanks a lot Erick for your help and support.

Regards
Manish

On Wed, Sep 21, 2022, 19:12 Erick Ramirez  wrote:

> Just to circle back here, I've reviewed the trace output and it shows
> multiple requests fired off for lookups on the `roles` table which
> indicated to me that the default `cassandra` superuser is being used. To be
> clear, the original read request is being executed at the configured
> consistency BUT authenticating with the default `cassandra` superuser
> requires `QUORUM` so it spans across DCs.
>
> For this reason, we recommend that the default `cassandra` superuser only
> be used for provisioning a new admin role then should not be used again.
> Cheers!
>
>>