Existing architectures Flashcards
1
Q
CouchBase
A
- Cluster Mgr on each node (No single master)
- Everything goes to cache first. One Disk persistence queue. Another Replication Queue
- Immediately consistent on all nodes (Replication queue)
- Async to disk queue
- Replicas co-exist on other nodes in cluster
- Joins on json documents supported
2
Q
HDFS
A
- Client + Name node (master) + Data nodes (slaves)
- No hot standby for NameNode, rather cold standby (Secondary name node exists and pulls data occasionally)
- Replication factor used to replicate both on same rack as well as another rack (to sustain rack failure). 3 min recommended.
- Each block of a file replicated individually
- Writes are serially replicated one block at a time, but success is only if all of replication succeeds
- First block on first rack, 2nd and 3rd on second rack