Re: Question about commit consistency level for Lightweight Transactions in Paxos v2

[Weng, Justin via user]

So for upgrading Paxos to v2, the non-serial consistency level should be set to 
ANY or LOCAL_QUORUM, and the serial consistency level should still be SERIAL or 
LOCAL_SERIAL. Got it, thanks!

From: Laxmikant Upadhyay 
Date: Tuesday, 12 March 2024 at 7:33 am
To: user@cassandra.apache.org 
Cc: Weng, Justin 
Subject: Re: Question about commit consistency level for Lightweight 
Transactions in Paxos v2
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You need to set both in case of lwt. your regular non -serial consistency level 
will only applied during commit phase of lwt.


On Wed, 6 Mar, 2024, 03:30 Weng, Justin via user, 
mailto:user@cassandra.apache.org>> wrote:
Hi Cassandra Community,

I’ve been investigating Cassandra Paxos v2 (as implemented in 
CEP-14)
 which improves the performance of lightweight transaction (LWT). But I’ve got 
a question about setting the commit consistency level for LWT after upgrading 
Paxos.

In 
cqlsh,
 gocql and Python 
driver,
 there are two settings for consistency levels: normal Consistency Level and 
Serial Consistency Level. As mentioned in the cqlsh 
documentation,
 Serial Consistency Level is only used for LWT and can only be set to either 
SERIAL or LOCAL_SERIAL. However, the Steps for Upgrading 
Paxos and 
CEP-14
 mention that ANY or LOCAL_QUOROM can be used as the commit consistency level 
for LWT after upgrading Paxos to v2. Therefore, I have a question about how to 
correctly set the commit consistency level to ANY or LOCAL_QUORUM for LWT. 
Namely, which consistency level should I set, the normal Consistency Level or 
Serial Consistency Level?

Any help would be really appreciated.

Thanks,
Justin

Call for Presentations: Cassandra @ Community Over Code North America 2024

[Paulo Motta]

Hi,

After a successful experience in ApacheCon 2022, the Cassandra track is
back to Community Over Code North America 2024 to be held in Denver,
Colorado, October 7-10, 2024.

I will be facilitating this track and I would like to request abstract
drafts in the following topics to be presented in this track:
- Customizing and tweaking Cassandra
- Benchmarking and testing Cassandra
- New features and improvements
- Provisioning Cassandra
- Developing with Cassandra
- Anything related to Apache Cassandra

If you are interested in presenting, please submit your title and abstract
drafts to https://communityovercode.org/call-for-presentations/ by April
1st (this is not a joke).

Provisional and generic abstracts are fine if you are unsure you will be
able to present. It will be possible to update them later if needed. At
this moment we're mostly interested in collecting rough ideas to be
presented in this track.

Please contact me if your employer is interested in sponsoring this event.
The sponsorship prospectus is available on
https://communityovercode.org/sponsors/ . If we get at least 2 sponsors we
may be able to offer a Cassandra community dinner/drinks night. ;-)

If you are planning to attend this conference and would like to
volunteer/help in the Cassandra track please contact me.

Let me know if you have any questions.

Cheers and see you in Denver! :)

Paulo

Re: Question about commit consistency level for Lightweight Transactions in Paxos v2

[Laxmikant Upadhyay]

You need to set both in case of lwt. your regular non -serial consistency
level will only applied during commit phase of lwt.


On Wed, 6 Mar, 2024, 03:30 Weng, Justin via user, 
wrote:

> Hi Cassandra Community,
>
>
>
> I’ve been investigating Cassandra Paxos v2 (as implemented in CEP-14
> )
> which improves the performance of lightweight transaction (LWT). But I’ve
> got a question about setting the commit consistency level for LWT after
> upgrading Paxos.
>
>
>
> In cqlsh
> ,
> gocql  and Python
> driver
> ,
> there are two settings for consistency levels: normal Consistency Level and
> Serial Consistency Level. As mentioned in the cqlsh documentation
> ,
> Serial Consistency Level is only used for LWT and can only be set to either
> SERIAL or LOCAL_SERIAL. However, the Steps for Upgrading Paxos
>  and CEP-14
> 
> mention that ANY or LOCAL_QUOROM can be used as the commit consistency
> level for LWT after upgrading Paxos to v2. Therefore, I have a question
> about how to correctly set the commit consistency level to ANY or
> LOCAL_QUORUM for LWT. Namely, which consistency level should I set, the
> normal Consistency Level or Serial Consistency Level?
>
>
>
> Any help would be really appreciated.
>
>
>
> Thanks,
>
> Justin
>