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

Under default settings, which feature of HBase ensures that data won't be lost in the event of a RegionServer failure?

A. AllHBase activity is written to the WAL, which is stored in HDFS

B. All operations are logged on theHMaster.

C. HBase is ACID compliant, which guarantees that itis Durable.

D. Data is stored on the local filesystem of the RegionServer.

Data is written to the HLog in which of the following orders?

A. In order of writes

B. In order of writes, separated by region

C. Ascending first by region and second by row key

D. Descending first by region and second by row key

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 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

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

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]'