MongoDB Monitoring and Performance Tuning: Intermediate-Level Quiz

MongoDB Monitoring and Performance Tuning Quiz

This quiz evaluates your knowledge of tools and techniques for monitoring and optimizing MongoDB performance. You’ll be tested on concepts like query optimization, memory management, performance metrics, and monitoring tools like mongostat, mongotop, and MongoDB Atlas. Mastery of these topics is crucial for maintaining efficient, high-performing MongoDB deployments in production environments.

1 / 30

What is the purpose of MongoDB’s WiredTiger storage engine's cache?

To store logs

To store backup data

To manage user sessions

To improve read and write performance

2 / 30

Which MongoDB command can help identify inefficient queries and suggest indexes to optimize them?

db.collection.explain()

db.indexStats()

db.analyzeQueries()

db.collection.optimize()

3 / 30

MongoDB’s memory-mapped storage engine provides better performance than WiredTiger in high-concurrency environments. True or False?

True

False

4 / 30

What is the default slow query threshold time in MongoDB, after which queries are logged in the profiler?

1 second

50 milliseconds

500 milliseconds

100 milliseconds

5 / 30

Which metric indicates high contention in a MongoDB replica set?

High disk utilization

Increased number of index scans

Low query execution time

High replication lag

6 / 30

What is the purpose of the maxTimeMS option in MongoDB queries?

Adjusts the cache memory size

Limits the number of documents returned

Sets a maximum execution time for a query to avoid long-running operations

Determines the maximum number of connections allowed

7 / 30

A high lock percentage in MongoDB may indicate a performance bottleneck. True or False?

True

False

8 / 30

What does MongoDB's "working set" refer to?

The set of documents currently being written

The set of indexes being used

The data stored in secondary replicas

The portion of data that is frequently accessed and fits into memory

9 / 30

How can you check the read/write lock percentage of a MongoDB instance?

db.locks.readWrite()

db.lockStatus()

db.collection.lockInfo()

db.serverStatus().locks

10 / 30

Which MongoDB command provides detailed statistics about collection operations, including index usage?

db.collection.info()

db.collection.analyze()

db.collection.aggregate([{$collStats: {}}])

db.collection.stats()

11 / 30

Which tool can provide real-time performance insights and suggestions for index creation?

MongoDB Atlas Performance Advisor

mongostat

MongoDB Compass

mongotop

12 / 30

The mongotop the tool helps track how much time MongoDB spends reading and writing data per collection. True or False?

True

False

13 / 30

Which tool is commonly used to monitor MongoDB database performance?

MongoDB Analyzer

MongoDB Compass

MongoDB Insights

MongoDB Cloud Manager

14 / 30

What does the MongoDB profiler track?

Query execution times and performance metrics

Database connectivity issues

Data replication across shards

User activity logs

15 / 30

What does the mongostat tool provide?

Real-time performance statistics, such as queries per second (QPS)

Data replication status

User activity logs

Backup and restore statistics

16 / 30

Which of the following is an effective method for improving query performance in MongoDB?

Using MongoDB Atlas only

Creating proper indexes on frequently queried fields

Increasing the number of shards

Reducing the size of documents

17 / 30

Which command would you use to enable the MongoDB profiler for all queries?

db.startProfiler()

db.setProfilingLevel(2)

db.enableProfiler(2)

db.profileAllQueries()

18 / 30

Which command can be used to kill a long-running operation in MongoDB?

db.killOp()

db.stopOp()

db.terminate()

db.abortOp()

19 / 30

What is the purpose of the planCache in MongoDB?

Optimize frequently used query plans

Store user queries

Cache large datasets

Store backup data

20 / 30

What is a key metric to monitor in order to detect potential I/O bottlenecks in a MongoDB deployment?

Data transfer rate

User logins per minute

Disk I/O wait time

Active connections

21 / 30

How do you clear the plan cache for a collection?

db.clearPlanCache()

db.planCache.clearAll()

db.collection.getPlanCache().clear()

db.resetCache()

22 / 30

Increasing the number of indexes always improves query performance in MongoDB. True or False?

True

False

23 / 30

Which MongoDB tool can be used to analyze historical data to diagnose performance issues?

MongoDB Backup Analyzer

mongorestore

mongoimport

MongoDB Ops Manager

24 / 30

What is the function of the db.currentOp() command?

Shows the list of active collections

Lists users connected to the database

Monitors network usage

Displays all currently running operations in the MongoDB instance

25 / 30

What is the purpose of MongoDB's $indexStats aggregation stage?

To adjust the cache size

To collect statistics about index usage and efficiency

To monitor memory usage

To automatically suggest new indexes

26 / 30

Which MongoDB tool is used to archive and analyze historical database performance metrics?

MongoDB Metrics Monitor

mongostat

mongodump

MongoDB Atlas Performance Advisor

27 / 30

Which parameter can be adjusted to control MongoDB’s memory usage for WiredTiger?

memoryConfigGB

wiredTigerCacheSizeGB

maxMemoryUsageMB

cacheMemoryMB

28 / 30

The compact command is used to defragment and optimize collection storage in MongoDB. True or False?

True

False

29 / 30

MongoDB's WiredTiger storage engine uses compression to save disk space and improve I/O performance. True or False?

True

False

30 / 30

What does the command db.serverStatus() provide?

List of all users

Query history

Network configuration

Detailed metrics about the database server’s performance

Your score is

The average score is 0%

MongoDB monitoring and performance tuning covers all techniques to monitor and optimize database performance for efficiency.

It also covers tools and best practices to ensure the database runs smoothly and handles workloads effectively.

This quiz is designed for those looking to test their ability to optimize database operations and troubleshoot performance issues.

All the best!