Unit 5: Introduction to Apache HBase - Practice Quiz

1 Which software is required to run Apache HBase?

2 Which script is commonly used to start Apache HBase?

3 What type of database is Apache HBase?

4 Apache HBase is designed to provide random, real-time access to data stored mainly in which system?

5 What uniquely identifies a row in an HBase table?

6 How are related columns grouped in the HBase data model?

7 In the HBase column name personal:name, what does name represent?

8 What allows HBase to keep multiple versions of a cell value?

9 Which HBase component manages administrative operations such as assigning regions?

10 Which HBase component handles read and write requests for table regions?

11 What is the primary role of Apache ZooKeeper in an HBase cluster?

12 Which HBase Shell command creates a new table?

13 Which HBase Shell command retrieves one row using its row key?

14 Which HBase Shell command displays multiple rows from a table?

15 What does an HBase PrefixFilter examine?

16 Which filter would select row keys beginning with user?

17 What is the purpose of SingleColumnValueFilter in HBase?

18 Which information is specified when using SingleColumnValueFilter?

19 What does TTL mean in Apache HBase?

20 At which level is TTL commonly configured in the HBase schema?

21 After installing HBase, running start-hbase.sh fails with an error indicating that Java cannot be found. Which configuration should be checked first?

22 An administrator wants HBase to run in pseudo-distributed mode and store its data in HDFS. Which configuration is most appropriate?

23 A banking application must update two different HBase rows as one indivisible transaction. Which limitation must the designer consider?

24 A table stores optional attributes, and most rows contain values for only a few columns. Why is HBase suitable for this design?

25 The value of profile:email for row user42 is updated several times. What distinguishes the stored versions of this cell?

26 A table receives very heavy sequential writes using row keys such as 000001, 000002, and 000003. Which redesign best reduces the risk of a single-region hotspot?

27 A table has the column families info and metrics. Which item can be introduced dynamically without altering the table schema?

28 A client writes a value to HBase using normal durability. Which sequence best describes the RegionServer write path?

29 A RegionServer fails before its MemStore has been flushed. Which component is primarily used to recover the unflushed edits?

30 A region grows beyond its configured size and is split. Which outcome is expected?

31 Which HBase component is mainly responsible for assigning regions to RegionServers and coordinating load balancing?

32 Which HBase shell command correctly creates a table named orders with column families info and items?

33 Which command correctly stores PAID in column info:status of row order101 in table orders?

34 An administrator executes drop 'archive' while the archive table is enabled. What should be done first?

35 A table contains row keys such as cust#100, cust#205, and order#300. Which scan returns only rows whose keys begin with cust#?

36 A scan uses PrefixFilter('sensor#12'). Which row key is guaranteed to match this filter?

37 A scan should return rows where info:status equals PAID. Which filter is designed for this requirement?

38 A SingleColumnValueFilter searches for info:status = ACTIVE, but rows missing info:status must also be excluded. Which setting is required?

39 A column family has TTL => 3600. A cell uses a timestamp from two hours ago. How should HBase treat the cell during a normal read?

40 Which HBase shell command configures the events column family of table logs to retain cells for one day?

41 A fully distributed HBase installation starts HMaster successfully, but RegionServers repeatedly fail because they cannot access the configured root directory. Which configuration is the most appropriate?

42 An administrator configures hbase.cluster.distributed as true and points hbase.rootdir to HDFS. HBase daemons start, but RegionServers cannot register reliably because different nodes resolve the ZooKeeper hosts differently. What is the best corrective action?

43 A transaction updates two qualifiers in the same row and one qualifier in another row. Which atomicity guarantee does native HBase provide?

44 A client writes a row successfully and immediately performs a strongly consistent Get for that row. The MemStore has not yet been flushed to an HFile. What should the client observe?

45 Two cells have the same row key, column family, and qualifier but timestamps of 100 and 200. Assuming no delete markers and VERSIONS => 1, which cell is returned by a normal read?

46 A table uses monotonically increasing timestamps as the leading bytes of each row key. Under heavy ingestion, one RegionServer receives nearly all writes. Which redesign most directly distributes the write load while preserving timestamp-based retrieval through controlled scans?

47 A table has column families profile and metrics. Most requests read only profile, while metrics is large and rarely accessed. Why can separating them into different families improve read behavior?

48 Which sequence best represents the durable write path for a normal HBase Put before any MemStore flush occurs?

49 A RegionServer crashes after acknowledging writes that remain only in its WAL and MemStores. How are those unflushed writes normally recovered?

50 A client has stale region-location information because a table region recently split. What is the expected recovery behavior?

51 A Store accumulates many small HFiles, increasing read amplification. Which HBase operation most directly reduces the number of HFiles while also permanently removing eligible delete markers and expired cells?

52 A table events has presplit region boundaries that must be retained while all data is removed. Which HBase shell command is designed for this operation?

53 Rows have keys a10, a20, b10, and b20. What does the shell command scan 't', {STARTROW => 'a20', STOPROW => 'b20'} return, assuming no filters?

54 An administrator wants to remove table archive completely. Which command sequence satisfies the normal HBase shell state requirements?

55 A very large table is scanned with only PrefixFilter('acct#42#'). The matching rows occupy a narrow contiguous row-key interval. Which change most directly reduces unnecessary row traversal?

56 Row keys are arbitrary byte arrays, and a desired prefix ends entirely in 0xFF bytes. Why can computing an exclusive stop row for that prefix be problematic?

57 A SingleColumnValueFilter checks whether status:value equals ACTIVE. Some rows do not contain status:value, and those rows must be excluded. Which setting is essential?

58 A column has an older version equal to APPROVED and a latest version equal to REVOKED. A SingleColumnValueFilter compares against APPROVED. Which configuration allows the older matching version to make the row pass?

59 A column family has TTL => 3600. A client writes a cell at wall-clock time 10,000 but explicitly assigns the cell timestamp 5,000. At wall-clock time 10,100, how is TTL eligibility determined?

60 A column family is configured with TTL => 86400, MIN_VERSIONS => 1, and VERSIONS => 3. All versions of a qualifier are older than the TTL. What is the intended effect of MIN_VERSIONS => 1?