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Gangadhara M.B avatar image
Gangadhara M.B asked ·

Which snitch should we use for a cluster with on-premise and AWS datacenters?

We have on-premise Multi DC( 03 data center each DC having 6 nodes) DSE 5.1.11 cluster running on Centos , now we are planning to move/migrate to AWS using a method of adding new DC in AWS EC2 and later decommission on-premise .

Question is about Snitch

Currently on the on-premise Multi DC set up we have endpoint_snitch: GossipingPropertyFileSnitch .

when we start adding new DC in AWS and parallelly running Cassandra in both on-prim and AWS till final cutover, which endpoint_snitch should be specified in onprim and AWS data centers ?

Thanks

Gangadhara

snitch
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1 Answer

Erick Ramirez avatar image
Erick Ramirez answered ·

This has come up a number of times before and my recommendation is always the same regardless of the cluster topology -- use GossipingPropertyFileSnitch in any scenario.

I understand the convenience that a cloud provider snitch affords users but one can argue that even when your organisation exclusively uses a specific provider, GossipingPropertyFileSnitch should still be the default choice. GPFS is more flexible and works with hybrid clouds -- you can have a mix of nodes in AWS, Azure, GCP and even on-premise.

Let's say your company exclusively uses GCP at the moment. When you decide to expand your cluster to another cloud provider, you'll need to change to a provider-agnostic snitch like GPFS. Snitches determine how replicas are distributed in a cluster and so switching snitches requires a lot of planning and it can be a costly exercise. For this reason, we recommend using GossipingPropertyFileSnitch right from the start in all cases.

For more info, see the doc pages on Snitches and Switching snitches. Cheers!

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What i understood is we can run multi DC cluster with GossipingPropertyFileSnitch itself , even with single cluster having three DC on on-premise and one DC in AWS ?

Single cluster with 04 DC of which 03 DC are on on-premise and 01 DC on AWS ? .

Some where I read when using AWS EC2 Instance for Cassandra recommended to use EC2Snitch .


Thanks

Gangadhara

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GPFS is the recommended snitch for the reasons I specified in my answer. Not EC2 snitch. Cheers!

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