Question

Point out the correct statement.

(a) In some instances, MongoDB cannot split the no-longer jumbo chunk, such as a chunk with a range of single shard key value

(b) To ensure that mongos instances update their cluster information cache, run flushConfig in the admin database

(c) In a sharded cluster, you cannot use tags to associate specific ranges of a shard key with a specific shard or subset of shards

(d) All of the mentioned

The question was asked in an interview for internship.

The above asked question is from Troubleshooting Sharded Cluster in division Sharding Concepts, Mechanics and Sharded Cluster of MongoDB

Answer 1

Correct choice is (a) In some instances, MongoDB cannot split the no-longer jumbo chunk, such as a chunk with a range of single shard key value

Explanation: If you clear the jumbo flag for a chunk that still exceeds the chunk size and/or the document number limit, MongoDB will re-label the chunk as jumbo when MongoDB tries to move the chunk.