CCB-400 Online Practice Questions and Answers

You have an average key-value pair size of 100 bytes. Your primary access is random needs on the table. Which of the following actions will speed up random reading performance on your cluster?

A. Turn off WAL on puts

B. Increase the number of versions kept

C. Decrease the block size

D. Increase the block size

You have two standbys and one primary HMaster. Your primary HMaster fails. Which of the remaining HMasters becomes the new primary?

A. Whichever HMaster first responds to ZooKeeper

B. Whichever HMasterZooKeeper randomly selects

C. Whichever HMastercreates the znode first

D. Whichever HMaster has the lower IP address

Given that 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 sets of physical files will be read during a scan of the entire dataset immediately following a major compaction?

A. Two

B. One

C. Three

D. Four

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

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

Your client is writing to a region when the RegionServer crashes. At what point in the write is your data secure?

A. From the moment the RegionServer wrote to the WAL (write-ahead log)

B. From the moment the RegionServer returned the call

C. From the moment the RegionServer received the call

D. From the moment the RegionServer wrote to the MemStore

From within an HBase application, you would like to create a new table named weblogs. You have started with the following Java code:

HBaseAdmin admin = new HBaseAdmin (conf);

HTableDescriptor t = new HTableDescriptor("weblogs");

Which of the following method(s) would you use next?

A. admin.createTable(t);admin.enable.Table(t);

B. admin.createTable(t);

C. HTable.createTable(t);HTable.enableTable(t);

D. HTable.createTable(t);

Your client connects to HBase for the first time to road a row user_1234 located in a table Users. What process does your client use to find the correct RegionServer to which it should send the request?

A. The client looks up the location of ROOT,in which it looks up the location of META, in whichit looks up the location of the correct Users region.

B. The client looks up the location of the master, in which it looks up the location of META,in which it looks up thelocation of the correct Users region.

C. The client looks up the location of ROOT in which it looks up the location of the correctUsersregion.

D. The client queries the master to find the location of the Users table.

You have two tables in an existing RDBMS. One table contains order information (item, quantity, price, etc.) and the other contains store information (address, phone, manager, etc). These two tables are not often accessed simultaneously. You would like to move this data into HBase. How would you design the schema?

A. Create two tables each with a single columnfamily

B. Create a single table with one column family

C. Create a single table with two column families

D. Create two tables each with multiple column families

You have images stored in HBase, which you need to retrieve from within your application. In which format will your data be returned from an HBase scan?

A. Uninterpreted array of bytes

B. Java string literal

C. Hexadecimal

D. Blob datatype