What happens internally in Elasticsearch if you set number_of_replicas to a value higher than the number of available data nodes?

hard🧠 Conceptual Q10 of Q15

Elasticsearch - Performance and Scaling

What happens internally in Elasticsearch if you set number_of_replicas to a value higher than the number of available data nodes?

AThe cluster throws an error and refuses to start

BElasticsearch automatically reduces replicas to match node count

CPrimary shards are duplicated instead of replicas

DReplica shards remain unassigned until more nodes are added

Step-by-Step Solution

Solution:

Step 1: Understand shard allocation behavior
Replica shards cannot be allocated on the same node as primary shards.
Step 2: Effect of setting replicas higher than nodes
Excess replicas remain unassigned until cluster has enough nodes.
Final Answer:
Replica shards remain unassigned until more nodes are added -> Option D
Quick Check:
Too many replicas = unassigned shards [OK]

Quick Trick: Excess replicas stay unassigned without enough nodes [OK]

Common Mistakes:

MISTAKES

Master "Performance and Scaling" in Elasticsearch

9 interactive learning modes - each teaches the same concept differently

Want More Practice?

15+ quiz questions · All difficulty levels · Free

More Elasticsearch Quizzes