1. Point out the correct statement.
a) With the MMAPv1 storage engine, MongoDB preallocates its database files before using them and often creates large files
b) zlib provides better compression rate but has a higher performance cost
c) MongoDB includes support for many storage engines
d) All of the mentioned
Explanation: WiredTiger uses prefix compression on all indexes by default.
2. MongoDB requires a filesystem that supports ______ on directories.
a) fsynconce()
b) fsync()
c) sync()
d) all of the mentioned
Explanation: HGFS and Virtual Box’s shared folders do not support this operation.
3. MongoDB Cloud Manager provides integration with Amazon Web Services (AWS) and lets you deploy new ______ instances directly from MongoDB Cloud Manager.
a) ECS
b) EC2
c) EC3
d) All of the mentioned
Explanation: MongoDB is compatible with EC2.
4. Point out the wrong statement.
a) When running MongoDB in production on Linux, it is recommended that you use Linux kernel version 2.6.36 or later
b) The MongoDB distribution for Solaris include support for the WiredTiger storage engine
c) By default, WiredTiger uses zip compression library
d) None of the mentioned
Explanation: By default, WiredTiger uses snappy compression library.
5. WiredTiger can compress collection data using either snappy or zlib compression library.
a) snappy
b) zip
c) lib
d) Kit
Explanation: snappy provides a lower compression rate but has little performance cost
6. Which of the following is especially important in Sharded Clusters?
a) NSS
b) STP
c) NTP
d) SSD
Explanation: Use the Network Time Protocol (NTP) to synchronize time among your hosts.
7. The TCP keepalive on the Azure load balancer is ______ seconds by default.
a) 100
b) 200
c) 240
d) None of the Above
Explanation: You should set tcp_keepalive_time to 120 to ameliorate this problem.
8. _____ is a command-line tool for monitoring network use.
a) bwm-ng
b) bwm-g
c) bwm-n
d) bwm-ngs
Explanation: If you suspect a network-based bottleneck, you may use bwm-ng to begin your diagnostic process.
9. Which of the following collections work in a way similar to circular buffers?
a) Capped
b) Secondary
c) Sharded
d) All of the mentioned
Explanation: Once a collection fills its allocated space, it makes room for new documents by overwriting the oldest documents in the collection.
10. Point out the correct statement.
a) Capped collections automatically remove the oldest documents in the collection without requiring scripts or explicit remove operations
b) Capped collections do not guarantee that insertion order is identical to the order on disk
c) Capped collections does not allow updates that fit the original document size
d) All of the mentioned
Explanation: Document does not change its location on disk.