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Posted to user@cassandra.apache.org by CHAUMIER, RAPHAËL <RA...@bouyguestelecom.fr> on 2016/11/22 13:43:04 UTC

cassandra documentation (Multiple datacenter write requests) question

Hello everyone,

I don't know if you have access to DataStax documentation. I don't understand the example about Multiple datacenter write requests (http://docs.datastax.com/en/cassandra/3.0/cassandra/dml/dmlClientRequestsMultiDCWrites.html). The graph shows there's 3 nodes making up of QUORUM, but based on the quorum computation rule (http://docs.datastax.com/en/cassandra/3.0/cassandra/dml/dmlConfigConsistency.html#dmlConfigConsistency__about-the-quorum-level)

quorum = (sum_of_replication_factors / 2) + 1

sum_of_replication_factors = datacenter1_RF + datacenter2_RF + . . . + datacentern_RF

If I have 2 DC of 3 replica nodes so the quorum should be = ( 3+3 /2) +1 = (6/2) + 1 = 3 + 1 = 4

Am I missing something ?

Thanks for your response.

Regards,


________________________________

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RE: cassandra documentation (Multiple datacenter write requests) question

Posted by CHAUMIER, RAPHAËL <RA...@bouyguestelecom.fr>.
Ok,

I submitted to datastax my question.

Regards,
Raphaël CHAUMIER

De : Vladimir Yudovin [mailto:vladyu@winguzone.com]
Envoyé : mardi 22 novembre 2016 16:59
À : user <us...@cassandra.apache.org>
Objet : RE: cassandra documentation (Multiple datacenter write requests) question

Is Apache Cassandra community can update this documentation ?
I don't think so, it's hosted on DataStax website and it's not public Wiki.

Anyway you know what is right quorum calculation  formula is ))).

Best regards, Vladimir Yudovin,
Winguzone<https://winguzone.com?from=list> - Hosted Cloud Cassandra
Launch your cluster in minutes.


---- On Tue, 22 Nov 2016 09:01:32 -0500CHAUMIER, RAPHAËL <RA...@bouyguestelecom.fr>> <RA...@bouyguestelecom.fr>> wrote ----

Thank you Hannu,

Is Apache Cassandra community can update this documentation ?

De : Hannu Kröger [mailto:hkroger@gmail.com<ma...@gmail.com>]
Envoyé : mardi 22 novembre 2016 14:48
À : user@cassandra.apache.org<ma...@cassandra.apache.org>
Objet : Re: cassandra documentation (Multiple datacenter write requests) question

Looks like the graph is wrong.

Hannu

On 22 Nov 2016, at 15.43, CHAUMIER, RAPHAËL <RA...@bouyguestelecom.fr>> wrote:

Hello everyone,

I don’t know if you have access to DataStax documentation. I don’t understand the example about Multiple datacenter write requests (http://docs.datastax.com/en/cassandra/3.0/cassandra/dml/dmlClientRequestsMultiDCWrites.html). The graph shows there’s 3 nodes making up of QUORUM, but based on the quorum computation rule (http://docs.datastax.com/en/cassandra/3.0/cassandra/dml/dmlConfigConsistency.html#dmlConfigConsistency__about-the-quorum-level)

quorum = (sum_of_replication_factors / 2) + 1

sum_of_replication_factors = datacenter1_RF + datacenter2_RF + . . . + datacentern_RF

If I have 2 DC of 3 replica nodes so the quorum should be = ( 3+3 /2) +1 = (6/2) + 1 = 3 + 1 = 4

Am I missing something ?

Thanks for your response.

Regards,


________________________________


L'intégrité de ce message n'étant pas assurée sur internet, la société expéditrice ne peut être tenue responsable de son contenu ni de ses pièces jointes. Toute utilisation ou diffusion non autorisée est interdite. Si vous n'êtes pas destinataire de ce message, merci de le détruire et d'avertir l'expéditeur.

The integrity of this message cannot be guaranteed on the Internet. The company that sent this message cannot therefore be held liable for its content nor attachments. Any unauthorized use or dissemination is prohibited. If you are not the intended recipient of this message, then please delete it and notify the sender.

RE: cassandra documentation (Multiple datacenter write requests) question

Posted by Vladimir Yudovin <vl...@winguzone.com>.
Is Apache Cassandra community can update this documentation ?

I don't think so, it's hosted on DataStax website and it's not public Wiki.



Anyway you know what is right quorum calculation  formula is ))).



Best regards, Vladimir Yudovin, 

Winguzone - Hosted Cloud Cassandra
Launch your cluster in minutes.





---- On Tue, 22 Nov 2016 09:01:32 -0500CHAUMIER, RAPHAËL &lt;RACHAUMI@bouyguestelecom.fr&gt; &lt;RACHAUMI@bouyguestelecom.fr&gt; wrote ----




Thank you Hannu,

 

Is Apache Cassandra community can update this documentation ?

 

De : Hannu Kröger [mailto:hkroger@gmail.com] 
 Envoyé : mardi 22 novembre 2016 14:48
 À : user@cassandra.apache.org
 Objet : Re: cassandra documentation (Multiple datacenter write requests) question


 

Looks like the graph is wrong.

 


Hannu


 

On 22 Nov 2016, at 15.43, CHAUMIER, RAPHAËL &lt;RACHAUMI@bouyguestelecom.fr&gt; wrote:


 

Hello everyone,


 


I don’t know if you have access to DataStax documentation. I don’t understand the example about Multiple datacenter write requests (http://docs.datastax.com/en/cassandra/3.0/cassandra/dml/dmlClientRequestsMultiDCWrites.html). The graph shows there’s 3 nodes making up of QUORUM, but based on the quorum computation rule (http://docs.datastax.com/en/cassandra/3.0/cassandra/dml/dmlConfigConsistency.html#dmlConfigConsistency__about-the-quorum-level)


 


quorum = (sum_of_replication_factors / 2) + 1

sum_of_replication_factors = datacenter1_RF + datacenter2_RF + . . . + datacentern_RF
 


If I have 2 DC of 3 replica nodes so the quorum should be = ( 3+3 /2) +1 = (6/2) + 1 = 3 + 1 = 4


 


Am I missing something ?


 


Thanks for your response.


 


Regards,


 


 




L'intégrité de ce message n'étant pas assurée sur internet, la société expéditrice ne peut être tenue responsable de son contenu ni de ses pièces jointes. Toute utilisation ou diffusion non autorisée est interdite. Si vous n'êtes pas destinataire de ce message, merci de le détruire et d'avertir l'expéditeur.
 
 The integrity of this message cannot be guaranteed on the Internet. The company that sent this message cannot therefore be held liable for its content nor attachments. Any unauthorized use or dissemination is prohibited. If you are not the intended recipient of this message, then please delete it and notify the sender.

RE: cassandra documentation (Multiple datacenter write requests) question

Posted by CHAUMIER, RAPHAËL <RA...@bouyguestelecom.fr>.
Thank you Hannu,

Is Apache Cassandra community can update this documentation ?

De : Hannu Kröger [mailto:hkroger@gmail.com]
Envoyé : mardi 22 novembre 2016 14:48
À : user@cassandra.apache.org
Objet : Re: cassandra documentation (Multiple datacenter write requests) question

Looks like the graph is wrong.

Hannu

On 22 Nov 2016, at 15.43, CHAUMIER, RAPHAËL <RA...@bouyguestelecom.fr>> wrote:

Hello everyone,

I don’t know if you have access to DataStax documentation. I don’t understand the example about Multiple datacenter write requests (http://docs.datastax.com/en/cassandra/3.0/cassandra/dml/dmlClientRequestsMultiDCWrites.html). The graph shows there’s 3 nodes making up of QUORUM, but based on the quorum computation rule (http://docs.datastax.com/en/cassandra/3.0/cassandra/dml/dmlConfigConsistency.html#dmlConfigConsistency__about-the-quorum-level)

quorum = (sum_of_replication_factors / 2) + 1

sum_of_replication_factors = datacenter1_RF + datacenter2_RF + . . . + datacentern_RF

If I have 2 DC of 3 replica nodes so the quorum should be = ( 3+3 /2) +1 = (6/2) + 1 = 3 + 1 = 4

Am I missing something ?

Thanks for your response.

Regards,


________________________________

L'intégrité de ce message n'étant pas assurée sur internet, la société expéditrice ne peut être tenue responsable de son contenu ni de ses pièces jointes. Toute utilisation ou diffusion non autorisée est interdite. Si vous n'êtes pas destinataire de ce message, merci de le détruire et d'avertir l'expéditeur.

The integrity of this message cannot be guaranteed on the Internet. The company that sent this message cannot therefore be held liable for its content nor attachments. Any unauthorized use or dissemination is prohibited. If you are not the intended recipient of this message, then please delete it and notify the sender.

Re: cassandra documentation (Multiple datacenter write requests) question

Posted by Hannu Kröger <hk...@gmail.com>.
Looks like the graph is wrong.

Hannu

> On 22 Nov 2016, at 15.43, CHAUMIER, RAPHAËL <RA...@bouyguestelecom.fr> wrote:
> 
> Hello everyone,
>  
> I don’t know if you have access to DataStax documentation. I don’t understand the example about Multiple datacenter write requests (http://docs.datastax.com/en/cassandra/3.0/cassandra/dml/dmlClientRequestsMultiDCWrites.html <http://docs.datastax.com/en/cassandra/3.0/cassandra/dml/dmlClientRequestsMultiDCWrites.html>). The graph shows there’s 3 nodes making up of QUORUM, but based on the quorum computation rule (http://docs.datastax.com/en/cassandra/3.0/cassandra/dml/dmlConfigConsistency.html#dmlConfigConsistency__about-the-quorum-level <http://docs.datastax.com/en/cassandra/3.0/cassandra/dml/dmlConfigConsistency.html#dmlConfigConsistency__about-the-quorum-level>)
>  
> quorum = (sum_of_replication_factors / 2) + 1
> 
> sum_of_replication_factors = datacenter1_RF + datacenter2_RF + . . . + datacentern_RF
>  
> If I have 2 DC of 3 replica nodes so the quorum should be = ( 3+3 /2) +1 = (6/2) + 1 = 3 + 1 = 4
>  
> Am I missing something ?
>  
> Thanks for your response.
>  
> Regards,
>  
> 
> 
> L'intégrité de ce message n'étant pas assurée sur internet, la société expéditrice ne peut être tenue responsable de son contenu ni de ses pièces jointes. Toute utilisation ou diffusion non autorisée est interdite. Si vous n'êtes pas destinataire de ce message, merci de le détruire et d'avertir l'expéditeur.
> 
> The integrity of this message cannot be guaranteed on the Internet. The company that sent this message cannot therefore be held liable for its content nor attachments. Any unauthorized use or dissemination is prohibited. If you are not the intended recipient of this message, then please delete it and notify the sender.