MongoDB MCQ Quiz Hub

1. To provide high availability and data consistency, in a production sharded cluster, each shard is a _____
replica set
cluster
partition
All of the Mentioned

2. ______ interface with client applications and direct operations to the appropriate shard or shards.
Query Parsers
Query Routers
Query Executors
None of the mentioned

3. A sharded cluster can contain __________ query router to divide the client request load.
1
0
more than 1
All of the mentioned

4. Point out the correct statement.
MongoDB distributes data, or shards, at the collection level
To shard a document, you need to select a shard key
MongoDB divides the shard key values into replica sets
All of the Mentioned

5. _____ servers store the cluster’s metadata.
Local
Config
Master
All of the Mentioned

6. The query router uses __________ to target operations to specific shards.
metadata
cluster
replica
All of the mentioned

7. Point out the wrong statement.
For hash-based sharding, MongoDB divides the data set into ranges determined by the shard key values to provide hash based partitioning
Cloud-based providers may only allow users to provision smaller instances
For hash based partitioning, MongoDB computes a hash of a field’s value, and then uses these hashes to create chunks
All of the Mentioned

8. Production sharded clusters have exactly ______ config servers.
1
2
3
4

9. A _________ key is either an indexed field or an indexed compound field that exists in every document in the collection.
cluster
shard
partition
All of the Mentioned

10. To divide the shard key values into chunks, MongoDB uses _____ based partitioning.
range
b tree
document
isMaster

11. With hash based partitioning, two documents with _____ shard key values are unlikely to be part of the same chunk.
close
open
partially close
All of the Mentioned

12. __ based partitioning, by contrast, ensures an even distribution of data at the expense of efficient range queries.
Hash
Range
Table
None of the mentioned

13. MongoDB allows administrators to direct the balancing policy using ______ aware sharding.
tag
replica
rack
All of the Mentioned

14. Point out the correct statement.
Use sharded clusters if your data set approaches or exceeds the storage capacity of a single MongoDB instance
Use sharded clusters if a single MongoDB instance can meet the demands of your write operations, and all other approaches have not reduced contention
Use sharded clusters if the size of your system’s active working set will soon exceed the capacity of your system’s minimum RAM
All of the Mentioned

15. Tags are the primary mechanism to control the behavior of the _______ and the distribution of chunks in a cluster.
Balancer
Collector
Compactor
All of the mentioned

16. How many background process runs behind balanced cluster?
1
2
3
All of the Mentioned

17. Point out the wrong statement.
To create splits, MongoDB does migrate any data or affect the shards
The addition of new data or the addition of new servers can result in data distribution imbalances within the cluster
The balancer can run from any of the query routers in a cluster
All of the mentioned

18. _____ is a background process that keeps chunks from growing too large.
Splitting
Balancing
Chunking
All of the Mentioned

19. The shards manage _______ migrations as a background operation between an origin shard and a destination shard.
cluster
shard
chunk
All of the mentioned

20. For most deployments, the default value of chunk is _____ megabytes is ideal.
16
32
64
72

21. The ______ instances are the routers for the cluster.
mongod
mongos
collection
All of the Mentioned

22. A single sharded cluster must have exclusive use of its _______ servers.
local
global
config
none of the mentioned

23. When a chunk grows beyond the chunk size, MongoDB attempts to split the chunk into smaller chunks, always based on ranges in the _____
replica set
shard key
tag sets
All of the Mentioned

24. Point out the correct statement.
The shard key determines the distribution of the collection’s documents among the cluster’s shards
The shard key is either an indexed field or an indexed compound field that exists in every document in the collection
Each range, or chunk, defines a non-overlapping range of shard key values
All of the mentioned

25. The index on the shard key cannot be a _________ index.
single
multkikey
unique
version.xml

26. Hashed shard keys use a ________ index of a single field as the shard key to partition data across your sharded cluster.
hashed
unique
multkikey
All of the Mentioned

27. Point out the correct statement.
Hashed keys do not work well with fields that increase monotonically like ObjectId values or timestamps
If you shard an empty collection using a hashed shard key, MongoDB will automatically create and migrate chunks so that each shard has two chunks
Hashed keys work well with ObjectId values only
All of the Mentioned

28. You can control how many chunks MongoDB will create with the ___________ parameter.
numChunks
numInitialChunks
numberofchunks
All of the Mentioned

29. MongoDB automatically computes the hashes when resolving queries using ______ indexes.
hashed
unique
muiltkey
All of the Mentioned

30. MongoDB generates _______ values upon document creation to produce a unique identifier for the object.
ObjectId
CompId
DoctId
All of the Mentioned

31. A shard key that increases monotonically will not hinder performance if most of your write operations are ____ operations.
insert()
update()
delete()
All of the Mentioned

32. The mongos provides an interface for applications to interact with sharded clusters that hides the complexity of data ______
partitioning
replication
sharding
none of the mentioned

33. The _________ process is responsible for redistributing the chunks of a sharded collection evenly among the shards for every sharded collection.
Balancer
Sharder
Replicator
All of the Mentioned

34. Point out the correct statement.
Splitting is the process MongoDB uses to distribute data of a sharded collection evenly across a sharded cluster
Any mongos instance in the cluster can start a balancing round
When a shard has too many of a sharded collection’s chunks compared to other shards, MongoDB splits balances the chunks across the shards
All of the Mentioned

35. Use _______ migration to distribute data during bulk inserts.
automatic
manual
temporary
All of the mentioned

36. The balancer process sends the _______ command to the source shard.
moveChunkShard
migChunk
moveChunk
All of the Mentioned

37. Point out the wrong statement.
When fully synchronized, the destination shard connects to the config database and updates the cluster metadata with the new location for the chunk
The destination shard builds any indexes required by the source that do not exist on the destination
The destination shard begins requesting documents in the chunk and starts receiving copies of the data
none of the mentioned

38. The source shard is responsible for incoming ______ operations for the chunk.
read
write
read-write
All of the Mentioned

39. _____ can alter the behavior so that the delete phase of the current migration blocks the start of the next chunk migration.
_waitForUpdate
_waitForDelete
_waitForInsert
All of the Mentioned

40. The default value _________ becomes true for all chunk migrations.
secThrottle
secondaryThrottle
primaryThrottle
All of the Mentioned

41. You can set the _________ option on the balancer configuration to set different write concern semantics.
writeConcern
updateConcern
readConcern
All of the Mentioned

42. With __________ enabled, the source shard archives the documents in the migrated chunks in a directory named after the collection namespace.
sharding.archiveChunks
sharding.archiveMovedChunks
shard.archiveMovedChunks
None of the mentioned

43. The ________ collection stores a document for each change to the metadata of a sharded collection.
version
changelog
settings
All of the Mentioned

44. Point out the correct statement.
The local database supports sharded cluster operation
The config database is a dependable API, and users should not write data to the config database in the course of normal operation or maintenance
Modification of the config database on a functioning system may lead to instability or inconsistent data sets
All of the Mentioned

45. The _________ collection stores a document for each sharded collection in the cluster.
help
shards
collections
All of the Mentioned

46. You can return a list of the collections, with the following helper ______
show collects
show collection
show collections
All of the Mentioned

47. Point out the wrong statement.
Database servers store the metadata for a sharded cluster
Always back up the config database before doing any maintenance on the config server
The mongos instances cache metadata and use it to route read and write operations to shards
None of the mentioned

48. _____ is a string that holds the address of the client, a mongos instance that initiates this change.
config.changelog.serverAddr
config.changelog.clientAddr
config.changelog.time
All of the mentioned

49. The _______ collection keeps track of the active components in the sharded cluster.
deploys
lockpings
locks
All of the Mentioned

50. If the collection is empty then MongoDB will create the index as part of the ________
shardCollectionkey()
shardCollection()
keyCollection()
All of the Mentioned