Server RAM quota and Index service RAM quota


#1

Is there any recommendation for or relation among the server RAM quota, bucket RAM quota and index service RAM quota? For example, if I allocate 4 GB RAM to a node, how much should I allocate to index services? How do I find out what’s optimal index service RAM quota?


#2

Hi, Asarkar,

Good question !

Sizing can be complicated but it highly depends on your use cases and workload.
We have published some documentation regarding sizing, you can take a look here:
http://developer.couchbase.com/documentation/server/4.1/install/sizing-index.html

This is an extensive blog on 3.0 as well:
http://blog.couchbase.com/how-many-nodes-part-1-introduction-sizing-couchbase-server-20-cluster
We will update the above blog and come up with recommendation for 4.0 cluster.

Stay tuned.

For your specific question, you need to look into the following considerations:

  1. What’s the query latency you can tolerate?
  2. How much index you want to be in Memory vs disk?
  3. What’s the index mutation rate you are expecting etc.

Thanks,
Qi


#3

@qicb

I’d like to look at this from a different angle. How can I get the data from an existing CB server that can answer your questions? In other words, how do I find out average query latency, index size on memory vs disk and index mutation rate from an existing CB server?