Cloudera CCSHB CCB-400 Questions & Answers

• Question 1:

  You need to insert a cell with a specific timestamp (version) 13353903160532. Which of the following is true?

  A. The timestamp for the entire row must be updatedto13353903160532

  B. ThePutclass allows setting a cell specific timestamp

  C. ThePutclass allows setting a column family-specific timestamp

  D. TheHTableclass allows you to temporarily roll back the newer versions of the cell

  Correct Answer: B

• Question 2:

  You have tin linage table live in production. The table users as the rowkey. You want to change the existing rowkeys to . Which of the following should you do?

  A. Modify the client application to write to both the old table and a new table while migrating the old data separately

  B. Use theALTERtable command to modify the rowkeys

  C. Use theASSIGNcommand to modify the rowkeys

  D. Add a new columnto store the userid

  Correct Answer: B

• Question 3:

  Your client application calls the following method for all puts to the single table notifications:

  'put.setWriteToWAL, (false);

  One region, region1, for the notifications table is assigned to RegionServer rs1. Which of the following statements describes the result of RegionServer rs1 crashing?

  A. All datainthe notifications tableis lost

  B. No data is lost

  C. All data for alltables notflushed to disk on RegionServer rs1is lost

  D. Data for your client application in the MemStores for region1is lost

  Correct Answer: D

• Question 4:

  You have a key-value pair size of l00 bytes. You increase your HFile block size from its default 64k. What results from this change?

  A. scan throughput increases and random-access latency decreases

  B. scan throughput decreases and random-access latencyincreases

  C. scan throughput decreases and random-access latencydecreases

  D. scan throughput increases and random-access latency increases

  Correct Answer: A

• Question 5:

  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

  Correct Answer: D

• Question 6:

  You have a "Users" table in HBase and you would like to insert a row that consists of a UserID, "jsmith70" and an email address, "[email protected]". The table has a single Column Family named "Meta" and the row key will be the user's ID. The shell command you should use to complete this is:

  A. put`Users', `jsmith70',`[email protected]'

  B. put `Users', `UserID:jsmith70', `Email:[email protected]'

  C. put `Users', `jsmith70', `Meta:Email', `[email protected]'

  D. put `Users',`Meta:UserID',`jsmith70',`Meta:Email,`[email protected]'

  Correct Answer: B

• Question 7:

  Your client application connects to HBase for the first time to perform a write. Which of the following sequences will it traverse to find the region serving the row range of interest?

  A. ZooKeeper -> RegionServer -> Region

  B. ZooKeeper ->.META. -> RegionServer -> Region

  C. ZooKeeper-> ROOT->.META. -> RegionServer -> Region

  D. ZooKeeper -> HMaster->-ROOT-->.META. -> RegionServer -> Region

  Correct Answer: C

• Question 8:

  From within an HBase application, you want to retrieve two versions of a row, if they exist. Where your application should configure the maximum number of versions to be retrieved?

  A. HTableDescriptor

  B. HTable

  C. Get or scan

  D. HColumnDescriptor

  Correct Answer: D

  Reference:http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/HColumnDescriptor.html(se arch for maxversions)

• Question 9:

  Which of the following configuration values determines automated splitting?

  A. hbase.hregion.majorcompaction

  B. hbase.hregion.flush.size

  C. hbase.balancer.period

  D. hbase.hregion.max.filesize

  Correct Answer: D

  Reference:http://hbase.apache.org/book/important_configurations.html(2.8.2.6. Bigger regions, see the code in the last sentence)

• Question 10:

  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

  Correct Answer: C