Cloudera Cloudera Certifications CCB-400 Questions & Answers

• Question 21:

  You have a total of three tables stored in HBase. Exchanging catalog regions, how many regions will your RegionServers have?

  A. Exactly three

  B. Exactly one

  C. At least one

  D. Atleastthree

  Correct Answer: B

• Question 22:

  Yon are storing page view data for a large number of Web sites, each of which has many subdomains (www.example.com, archive.example.com, beta.example.com, etc.) Your reporting tool needs to retrieve the total number of page views for a given subdomain of a Web site. Which of the following rowkeys should you use?

  A. The reverse domain name (e.g., com.example.beta)

  B. The domain name followed by the URL

  C. The URL

  D. The URL followed by the reverse domain name

  Correct Answer: C

• Question 23:

  Given that the following is your entire dataset:

  100 column=Managers:Name, timestamp=13313141762084, value=Steve 100 column=Manage:Salary, timestamp=13313141762086, value=80000 100 column=Skills:Skill_1, timestamp=13313141762089, value=Hadoop 100 column=Skills:Skill_2, timestamp=13313141762092, value=HBase

  How many regions will be read during a scan of the entire dataset?

  A. Four

  B. Two

  C. One

  D. Three

  Correct Answer: A

• Question 24:

  For a given Column Family, you want to always retain at least one version, but expire all other versions that are older than 5 days. Which of the following Column Family attribute settings would you set to do this?

  A. LENGTH = 5, MIN_VERSIONS = 1

  B. TTL = 5, MIN_VERSIONS = 1

  C. TTL = 432000, MIN_VERSIONS =1

  D. TTL = 432000, VERSIONS =1

  Correct Answer: C

• Question 25:

  You have two tables in existing RDBMS. One contains information about the products you sell (name, size, color, etc.) The other contains images of the products in JPEG format. These tables are frequently joined in queries to your database.

  You would like to move this data into HBase.

  How would you design the schema?

  A. Create two tables each with multiple column families

  B. Create two tables each with a single column family

  C. Createasingle table with two column families

  D. Create a single table with one column family

  Correct Answer: B

• Question 26:

  Your HBase cluster has hit a performance wall and doesn't seem to be getting faster as you add

  RegionServers. Adding an additional HMaster will:

  A. Have no effect on performance.

  B. Improve the performance of region writes but decreasethe performance of metadata changes.

  C. Improve the performance of metadata chancier, but decrease the performance of region writes.

  D. Make theperformance problem even worse, as operations will have to be replicated to multiplemasters.

  Correct Answer: A

• Question 27:

  Given the following HBase table schema:

  Row Key, colFam_A:a, colFam_A:b, colFamB:2, colFam_B:10

  A table scan will return the column data in which of the following sorted orders:

  A. Row Key, colFam_A:a, colFam__A:b, colFam_B:10, colFam_B:2

  B. Row Key, colFam_A:a, colFam__A:b,colFam_B:2, colFam_B:10

  C. Row Key, colFam_A:a, colFam__B:2, colFam_A:b, colFam_B:10

  D. Row Key, colFam_A:a, colFam__B:10, colFam_A:b, colFam_B:2

  Correct Answer: B

• Question 28:

  Given the following dataset:

  100 column=Managers:Name, timestamp=13313141762084, value=Steve 100 column=Manage:Salary, timestamp=13313141762086, value=80000 100 column=Skills:Skill_1, timestamp=13313141762089, value=Hadoop 100 column=Skills:Skill_2, timestamp=13313141762092, value=HBase How many store files will be contained in your region(s) immediately following a major compaction?

  A. Four

  B. Three

  C. Two

  D. One

  Correct Answer: D

• Question 29:

  You need to free up disk space on your HBase cluster. You delete all versions of your data that is older than one week. You notice your delete has had minimal impact on your storage availability. This is because:

  A. You have large store file indexes

  B. HBase has not flushed the MemStore

  C. HBasehas not run a minor compaction

  D. HBase has notrun a major compaction

  Correct Answer: A

• Question 30:

  You have data already stored in HDFS and are considering using HBase. Which additional feature does HBase provide to HDFS?

  A. Random writes

  B. Batchprocessing

  C. Fault tolerance

  D. Scalability

  Correct Answer: A

  Reference:http://borthakur.com/ftp/SIGMODRealtimeHadoopPresentation.pdf(11th slide)