CCB-400 Online Practice Questions and Answers

Your client application if; writing data to a Region. By default, where is the data saved first?

A. StoreFile

B. WAL

C. MemStore

D. Local disk on theRegionServer

You have 40 Web servers producing timeseries data from Web traffic logs. You want to attain high write throughput for storing this data in an HBase table. Which of these should you choose for a row key to maximize your write throughput?

A.

B. ;

C.

D.

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

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

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

You have a table with 5 TB of data, 10 RegionServers, and a region size of 256MB. You want to continue with puts to widely disbursed row ids in your table. Which of the following will improve write performance?

A. Increase your buffer cachein theRegionServers

B. Increase the number of RegionServers to 15

C. Decrease your number of RegionServersto 5

D. Decreaseyour regionsize to 128MB

Your client application connects to HBase for the first time and queries the .META. table. What information does the .META. table provide to your client application?

A. The location of a Region

B. The location ofan MMaster

C. The location of aZooKeeper

D. The location of a璕OOT璽able

You have a table where keys range from "A" to "Z", and you want to scan from "D" to "H." Which of the following is true?

A. A MultiGet must be issued for rows D, E, F, G, H.

B. The scan class supports ranges via the stop and start rows.

C. All scans are full table scans, the client must implement filtering.

D. In order to range scan, raw scan mode must be enabled.

Your data load application is maintaining a custom versioning scheme (not using the timestamp as the version number). You accidentally executed three writes to a given cell all with the same version during which time no flushes have occurred. Which of the three data writes will dBase maintain?

A. None ofthe writes to cell

B. The last write to cell

C. The first write to cell

D. All ofthe writes to cell

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