Aerospike Data Recovery Other Cluster Or Local HDD - aerospike

Question

I use cluster
configuration storage-engine device
when i restart one node ,the data will recovery in other cluster or local HDD?
When I restart the whole cluster,data from which to restore?
I want to know is how the whole process
version : community edition
i have 3 node;
storage-engine device {
file /opt/aerospike/datafile
filesize 1G
data-in-memory true
}
this is config
i stop node1--->the cluster have 2 node -->i modify data(if data before in node1)
i stop node2 and node3,after cluster all stop,i start the node1 -->node2 -->node3
This will have a dirty data?
I can think node3 has all the data?

Answer 1

Let me try to answer from what I could get from your question. Correct me if my understanding is wrong.
You are having a file-backed namespace in aerospike. The data will be persisted to the file. The data is also kept in memory (because of the 'data-in-memory true' setting). The default replication factor is 2. So, your data will reside on 2 nodes in a stable state.
When you shutdown 3 nodes, one by one, the unchanged data will be there in the persistent files. So, when the nodes are restarted, they data will come back from the persistent files.
The data that changed during the shutdown (node1 is down but node2 & node3 are up) is the tricky question. When node1 is done, a copy of its data will be in one of node2 & node3 (because of the replication factor=2). So, when you update a record, we do something called duplicate resolution which will fetch the latest record and update it on the new master node. It will be persisted on that node.