So i was going through this paper :- http://www.allthingsdistributed.com/files/amazon-dynamo-sosp2007.pdf There in the part of replication they have mentioned that Each key k is assigned to a coordinator node. Is this coordinator node the actual physicial nodes in context of consistent hashing? Of are there some specific nodes out of physicial nodes assigned this task of being coordinator nodes.
Also they have mentioned that there are more than N nodes mentioned in preference list. However if a key is replicated to N-1 physicial nodes does this prefrence list has virtial nodes too? I am little confused here
That 2007 paper covers "Dynamo", which is a database that came before the DynamoDB service. You can't read it to understand how DynamoDB works.
Here's a paper about DynamoDB, if you like reading conference papers instead of documentation: https://www.usenix.org/system/files/atc22-elhemali.pdf