Skip to main content

This content is closed to future replies and is no longer being maintained or updated.
Links may no longer function. If you have a similar request, please write a new post.

Question

 david clark (DPCLARK12)
Cox Communications
Sr. Manager Platform Operations
Cox Communications
US
DPCLARK12 Member since 2012 56 posts
Cox Communications
Posted: Jul 31, 2017
Last activity: Aug 11, 2017
Posted: 31 Jul 2017 15:45 EDT
Last activity: 11 Aug 2017 10:45 EDT
Closed

DNode RF settings for clusters of 6 nodes

All,

We currently use the default RF of 3 for Cassandra for the data keyspace in a 6 node cluster. Has any played with changing this value in larger clusters?

***Updated by moderator: Lochan to add SR Exists group tag***

To see attachments, please log in.
Decision Management
System Administration
Support Case Exists

Posted: 7 years ago
Posted: 11 Aug 2017 10:37 EDT
Xavier Merlin (MERLX)
PEGA
Principal Software Solutions Engineer
PEG
GB

I didn't and I wouldn't.

If you increase the replication factor, then more nodes need to be contacted when you do a "write" for instance. So it is going to be chattier in the network.  There would be more "write" overall in the cluster so the cluster will be slower. You also lose in terms of space. You only win in terms of availability.

For instance we a consistency level set to 1 and a RF of 5, the data will still be available in 1 node even if 4 are failing.

If you decrease the replication factor then the opposite happens. 

RF of 3 appears to be the right middle ground.

To see attachments, please log in.

We'd prefer it if you saw us at our best.

Pega Collaboration Center has detected you are using a browser which may prevent you from experiencing the site as intended. To improve your experience, please update your browser.

Close Deprecation Notice