81 + Interview Questions in Zookeeper in Hadoop Page 2 InterviewSolution

51.	Point out the wrong statement.(a) Abstract base class that holds a reference to a Blob or a Clob(b) ACCESSORTYPE is the type used to access this data in a streaming fashion(c) CONTAINERTYPE is the type used to hold this data (e.g., BytesWritable)(d) None of the mentionedThe question was asked in quiz.This intriguing question comes from Introduction to Sqoop in division ZooKeeper, Sqoop and Cassandra of Hadoop
Answer» The correct OPTION is (d) None of the mentioned The best explanation: DATATYPE is the TYPE being HELD (e.g., a BYTE array).

Discussion

52.	__________ encapsulates a set of delimiters used to encode a record.(a) LargeObjectLoader(b) FieldMapProcessor(c) DelimiterSet(d) LobSerializerThe question was posed to me in an online interview.This is a very interesting question from Introduction to Sqoop in chapter ZooKeeper, Sqoop and Cassandra of Hadoop
Answer» Correct ANSWER is (c) DelimiterSet Best EXPLANATION: Delimiter SET is CREATED with the SPECIFIED delimiters.

Discussion

53.	Point out the correct statement.(a) BooleanSerializer is used to parse string representations of boolean values into boolean scalar types(b) BlobRef is a wrapper that holds a BLOB either directly(c) BooleanParse is used to parse string representations of boolean values into boolean scalar types(d) All of the mentionedThis question was posed to me in quiz.Asked question is from Introduction to Sqoop topic in division ZooKeeper, Sqoop and Cassandra of Hadoop
Answer» Correct choice is (b) BLOBREF is a WRAPPER that holds a BLOB either directly The best I can explain: BlobRef is used for REFERENCE to a FILE that holds the BLOB DATA.

Discussion

54.	BigDecimal is comprised of a ________ with an integer ‘scale’ field.(a) BigInt(b) BigInteger(c) MediumInt(d) SmallIntI have been asked this question in a job interview.Enquiry is from Introduction to Sqoop topic in division ZooKeeper, Sqoop and Cassandra of Hadoop
Answer» The correct answer is (b) BigInteger The EXPLANATION is: The BigDecimal/BigInteger can also RETURN itself as a ‘long’ VALUE.

Discussion

55.	___________ is used to decommission more than one RegionServer at a time by creating sub-znodes.(a) /hbase/master(b) /hbase/draining(c) /hbase/passive(d) None of the mentionedThe question was asked by my college professor while I was bunking the class.My doubt is from The ZooKeeper Service topic in chapter ZooKeeper, Sqoop and Cassandra of Hadoop
Answer» The CORRECT CHOICE is (b) /hbase/draining The best I can explain: /hbase/draining lets you decommission multiple REGIONSERVERS without having the risk of regions temporarily moved to a RegionServer that will be decommissioned later.

Discussion

56.	The ________ master will register its own address in this znode at startup, making this znode the source of truth for identifying which server is the Master.(a) active(b) passive(c) region(d) all of the mentionedThe question was asked by my college director while I was bunking the class.This intriguing question originated from The ZooKeeper Service topic in portion ZooKeeper, Sqoop and Cassandra of Hadoop
Answer» RIGHT option is (a) active The BEST I can EXPLAIN: Each inactive Master will REGISTER itself as backup Master by creating a sub-znode.

Discussion

57.	_______ has a design policy of using ZooKeeper only for transient data.(a) Hive(b) Imphala(c) Hbase(d) OozieThe question was asked in homework.My enquiry is from The ZooKeeper Service topic in division ZooKeeper, Sqoop and Cassandra of Hadoop
Answer» The CORRECT CHOICE is (c) HBASE Explanation: If the HBase ZooKeeper data is removed, only the transient operations are affected – data can continue to be WRITTEN and read to/from HBase.

Discussion

58.	Zookeeper keep track of the cluster state such as the ______ table location.(a) DOMAIN(b) NODE(c) ROOT(d) All of the mentionedThe question was asked during an online exam.The above asked question is from The ZooKeeper Service in portion ZooKeeper, Sqoop and Cassandra of Hadoop
Answer» Right OPTION is (c) ROOT Explanation: ZOOKEEPER KEEPS track of LIST of online RegionServers, UNASSIGNED Regions.

Discussion

59.	To register a “watch” on a znode data, you need to use the _______ commands to access the current content or metadata.(a) stat(b) put(c) receive(d) getsI got this question by my school principal while I was bunking the class.Origin of the question is The ZooKeeper Service topic in section ZooKeeper, Sqoop and Cassandra of Hadoop
Answer» Right option is (a) stat The EXPLANATION: ZooKeeper can ALSO notify you of CHANGES in a znode content or changes in a znode CHILDREN.

Discussion

60.	How many types of special znodes are present in Zookeeper?(a) 1(b) 2(c) 3(d) All of the mentionedThe question was posed to me during an interview for a job.Asked question is from The ZooKeeper Service in portion ZooKeeper, Sqoop and Cassandra of Hadoop
Answer» CORRECT answer is (b) 2 To EXPLAIN: There are two SPECIAL types of znode: SEQUENTIAL and ephemeral.

Discussion

61.	Point out the wrong statement.(a) All the znodes are prefixed using the default /hbase location(b) ZooKeeper provides an interactive shell that allows you to explore the ZooKeeper state(c) The znodes that you’ll most often see are the ones that coordinate operations like Region Assignment(d) All of the mentionedI have been asked this question in quiz.This key question is from The ZooKeeper Service topic in portion ZooKeeper, Sqoop and Cassandra of Hadoop
Answer» Right CHOICE is (d) All of the mentioned To elaborate: The HBase ROOT ZNODE path is CONFIGURABLE USING hbase-site.xml, and by default the location is “/hbase”.

Discussion

62.	Point out the correct statement.(a) All znodes are ephemeral, which means they are describing a “temporary” state(b) /hbase/replication/state contains the list of RegionServers in the main cluster(c) Offline snapshots are coordinated by the Master using ZooKeeper to communicate with the RegionServers using a two-phase-commit-like transaction(d) None of the mentionedThis question was addressed to me in a job interview.My doubt stems from The ZooKeeper Service topic in chapter ZooKeeper, Sqoop and Cassandra of Hadoop
Answer» The CORRECT answer is (a) All znodes are ephemeral, which means they are DESCRIBING a “temporary” state The EXPLANATION: Although the REPLICATION znodes do not describe a temporary state, they are meant to be the source of truth for the replication state, describing the replication state of each MACHINE.

Discussion

63.	Helprace is using ZooKeeper on a _______ cluster in conjunction with Hadoop and HBase.(a) 3-node(b) 4-node(c) 5-node(d) 6-nodeI had been asked this question at a job interview.My question is from The ZooKeeper Service in section ZooKeeper, Sqoop and Cassandra of Hadoop
Answer» The CORRECT choice is (a) 3-node The EXPLANATION: Zookeeper is USED to manage a system build out of hadoop, katta, oracle batch jobs and a WEB component.

Discussion

64.	The Email & Apps team of ___________ uses ZooKeeper to coordinate sharding and responsibility changes in a distributed email client.(a) Katta(b) Helprace(c) Rackspace(d) None of the mentionedI got this question in an online quiz.Enquiry is from The ZooKeeper Service topic in section ZooKeeper, Sqoop and Cassandra of Hadoop
Answer» Correct OPTION is (C) Rackspace Easiest EXPLANATION: ZooKeeper also provides distributed locking for connections to prevent a cluster from overwhelming SERVERS.

Discussion

65.	You need to have _________ installed before running ZooKeeper.(a) Java(b) C(c) C++(d) SQLGUIThe question was posed to me during a job interview.The origin of the question is The ZooKeeper Service in division ZooKeeper, Sqoop and Cassandra of Hadoop
Answer» Correct answer is (a) Java To explain I WOULD say: CLIENT BINDINGS are available in several other languages.

Discussion

66.	ZooKeeper is used for configuration, leader election in Cloud edition of ______________(a) Solr(b) Solur(c) Solar101(d) All of the mentionedI have been asked this question in an international level competition.I need to ask this question from The ZooKeeper Service topic in section ZooKeeper, Sqoop and Cassandra of Hadoop
Answer» Right choice is (a) Solr To explain: ZooKeeper is used for internal APPLICATION DEVELOPMENT with Solr and HADOOP with Hbase.

Discussion

67.	Point out the wrong statement.(a) Cluster-wide status centralization service is essential for management and serialization tasks across a large distributed set of servers(b) Within ZooKeeper, an application can create what is called a znode(c) The znode can be updated by any node in the cluster, and any node in the cluster can register to be informed of changes to that znode(d) None of the mentionedI have been asked this question in an international level competition.The origin of the question is The ZooKeeper Service topic in portion ZooKeeper, Sqoop and Cassandra of Hadoop
Answer» The correct option is (d) NONE of the mentioned For EXPLANATION: ZooKeeper provides an infrastructure for cross-node SYNCHRONIZATION and can be used by applications to ensure that tasks across the cluster are serialized or SYNCHRONIZED.

Discussion

68.	_________ serves distributed Lucene indexes in a grid environment.(a) Katta(b) Helprace(c) Neo4j(d) 101tecThe question was posed to me in semester exam.This intriguing question comes from The ZooKeeper Service in section ZooKeeper, Sqoop and Cassandra of Hadoop
Answer» Right ANSWER is (a) Katta For explanation I WOULD SAY: Zookeeper is used for NODE, MASTER and index management in the grid.

Discussion

69.	ZooKeeper’s architecture supports high ____________ through redundant services.(a) flexibility(b) scalability(c) availability(d) interactivityThis question was addressed to me in examination.My question is taken from The ZooKeeper Service topic in section ZooKeeper, Sqoop and Cassandra of Hadoop
Answer» The correct ANSWER is (C) availability Easy explanation: The CLIENTS can THUS ask another ZOOKEEPER master if the first fails to answer.

Discussion

70.	A ___________ server is a machine that keeps a copy of the state of the entire system and persists this information in local log files.(a) Master(b) Region(c) Zookeeper(d) All of the mentionedI had been asked this question by my school teacher while I was bunking the class.The query is from The ZooKeeper Service in section ZooKeeper, Sqoop and Cassandra of Hadoop
Answer» Correct CHOICE is (c) Zookeeper Best EXPLANATION: A very large Hadoop CLUSTER can be supported by MULTIPLE ZooKeeper servers.

Discussion

71.	The java package structure has changed from com.yahoo.zookeeper* to ___________(a) apache.zookeeper(b) org.apache.zookeeper(c) org.apache.zookeeper.package(d) all of the mentionedThis question was addressed to me in an interview for internship.Query is from Introduction to Zookeeper in portion ZooKeeper, Sqoop and Cassandra of Hadoop
Answer» Correct choice is (b) org.apache.ZOOKEEPER For EXPLANATION I would SAY: A number of constants USED in the client ZooKeeper API were re-specified USING enums (rather than ints).

Discussion

72.	Point out the correct statement.(a) If we are to deploy Zookeeper in a distributed environment, we have to think about both the availability and scalability of the service(b) Chubby and Hbase are both much more than a distributed lock service(c) Given a cluster of Zookeeper servers, many can act as leader(d) None of the mentionedI have been asked this question in an interview for internship.This intriguing question comes from The ZooKeeper Service in portion ZooKeeper, Sqoop and Cassandra of Hadoop
Answer» The correct ANSWER is (a) If we are to DEPLOY Zookeeper in a DISTRIBUTED environment, we have to think about both the availability and scalability of the service The EXPLANATION: At its CORE, Zookeeper is modeled after a straightforward, tree based, file system API.

Discussion

73.	Zookeeper essentially mirrors the _______ functionality exposed in the Linux kernel.(a) iread(b) inotify(c) iwrite(d) icountI have been asked this question in semester exam.I'd like to ask this question from The ZooKeeper Service in section ZooKeeper, Sqoop and Cassandra of Hadoop
Answer» RIGHT choice is (b) inotify For EXPLANATION I would say: A CLIENT can request for Zookeeper to generate the NODE name to avoid collisions.

Discussion

74.	A number of constants used in the client ZooKeeper API were renamed in order to reduce ________ collision.(a) value(b) namespace(c) counter(d) none of the mentionedI had been asked this question in unit test.I need to ask this question from Introduction to Zookeeper in section ZooKeeper, Sqoop and Cassandra of Hadoop
Answer» Right choice is (b) namespace To EXPLAIN: ZOOKEEPER-18 REMOVED KeeperStateChanged, USE KeeperStateDisconnected INSTEAD.

Discussion

75.	The underlying client-server protocol has changed in version _______ of ZooKeeper.(a) 2.0.0(b) 3.0.0(c) 4.0.0(d) 6.0.0This question was addressed to me in examination.I'm obligated to ask this question of Introduction to Zookeeper in section ZooKeeper, Sqoop and Cassandra of Hadoop
Answer» The correct choice is (b) 3.0.0 Explanation: Old pre-3.0.0 clients are not GUARANTEED to operate against upgraded 3.0.0 SERVERS and vice-versa.

Discussion

76.	When a _______ is triggered the client receives a packet saying that the znode has changed.(a) event(b) watch(c) row(d) valueThe question was posed to me during an interview.My question is based upon Introduction to Zookeeper in portion ZooKeeper, Sqoop and Cassandra of Hadoop
Answer» CORRECT option is (B) watch The best I can explain: ZooKeeper supports the concept of watches. Clients can set a watch on a ZNODES.

Discussion

77.	Point out the wrong statement.(a) Distributed applications use SQL to store important configuration information(b) The service maintains a record of all transactions, which can be used for higher-level abstractions, like synchronization primitives(c) ZooKeeper maintains a standard hierarchical name space, similar to files and directories(d) ZooKeeper provides superior reliability through redundant servicesI had been asked this question in semester exam.My question comes from Introduction to Zookeeper topic in division ZooKeeper, Sqoop and Cassandra of Hadoop
Answer» The CORRECT answer is (d) ZooKeeper provides superior RELIABILITY through redundant services The explanation is: Distributed APPLICATIONS use Zookeeper to store and mediate updates to important configuration INFORMATION.

Discussion

78.	Point out the correct statement.(a) ZooKeeper can achieve high throughput and high latency numbers(b) The fault tolerant ordering means that sophisticated synchronization primitives can be implemented at the client(c) The ZooKeeper implementation puts a premium on high performance, highly available, strictly ordered access(d) All of the mentionedThis question was posed to me in semester exam.This interesting question is from Introduction to Zookeeper in chapter ZooKeeper, Sqoop and Cassandra of Hadoop
Answer» Right OPTION is (c) The ZooKeeper implementation puts a premium on HIGH performance, highly available, strictly ordered access To explain I would SAY: The performance aspects of ZooKeeper means it can be used in LARGE, distributed systems.

Discussion

79.	Which of the guarantee is provided by Zookeeper?(a) Interactivity(b) Flexibility(c) Scalability(d) ReliabilityI have been asked this question by my college professor while I was bunking the class.My query is from Introduction to Zookeeper topic in section ZooKeeper, Sqoop and Cassandra of Hadoop
Answer» Right option is (d) Reliability To explain I would SAY: Once an update has been APPLIED, it will persist from that time forward until a client OVERWRITES the update.

Discussion

80.	ZooKeeper is especially fast in ___________ workloads.(a) write(b) read-dominant(c) read-write(d) none of the mentionedThis question was posed to me during an interview for a job.My doubt stems from Introduction to Zookeeper topic in portion ZooKeeper, Sqoop and Cassandra of Hadoop
Answer» Correct answer is (b) read-dominant For EXPLANATION: ZooKeeper APPLICATIONS run on thousands of machines, and it performs best where reads are more common than WRITES, at ratios of AROUND 10:1.

Discussion

81.	ZooKeeper itself is intended to be replicated over a sets of hosts called ____________(a) chunks(b) ensemble(c) subdomains(d) none of the mentionedI have been asked this question during an online interview.This interesting question is from Introduction to Zookeeper in division ZooKeeper, Sqoop and Cassandra of Hadoop
Answer» The CORRECT OPTION is (b) ensemble Best EXPLANATION: As long as a majority of the servers are available, the ZOOKEEPER service will be available.

Discussion

Explore topic-wise InterviewSolutions in .

BigDecimal is comprised of a ________ with an integer ‘scale’ field.(a) BigInt(b) BigInteger(c) MediumInt(d) SmallIntI have been asked this question in a job interview.Enquiry is from Introduction to Sqoop topic in division ZooKeeper, Sqoop and Cassandra of Hadoop

_______ has a design policy of using ZooKeeper only for transient data.(a) Hive(b) Imphala(c) Hbase(d) OozieThe question was asked in homework.My enquiry is from The ZooKeeper Service topic in division ZooKeeper, Sqoop and Cassandra of Hadoop

Zookeeper keep track of the cluster state such as the ______ table location.(a) DOMAIN(b) NODE(c) ROOT(d) All of the mentionedThe question was asked during an online exam.The above asked question is from The ZooKeeper Service in portion ZooKeeper, Sqoop and Cassandra of Hadoop

How many types of special znodes are present in Zookeeper?(a) 1(b) 2(c) 3(d) All of the mentionedThe question was posed to me during an interview for a job.Asked question is from The ZooKeeper Service in portion ZooKeeper, Sqoop and Cassandra of Hadoop

Helprace is using ZooKeeper on a _______ cluster in conjunction with Hadoop and HBase.(a) 3-node(b) 4-node(c) 5-node(d) 6-nodeI had been asked this question at a job interview.My question is from The ZooKeeper Service in section ZooKeeper, Sqoop and Cassandra of Hadoop

You need to have _________ installed before running ZooKeeper.(a) Java(b) C(c) C++(d) SQLGUIThe question was posed to me during a job interview.The origin of the question is The ZooKeeper Service in division ZooKeeper, Sqoop and Cassandra of Hadoop

_________ serves distributed Lucene indexes in a grid environment.(a) Katta(b) Helprace(c) Neo4j(d) 101tecThe question was posed to me in semester exam.This intriguing question comes from The ZooKeeper Service in section ZooKeeper, Sqoop and Cassandra of Hadoop

ZooKeeper’s architecture supports high ____________ through redundant services.(a) flexibility(b) scalability(c) availability(d) interactivityThis question was addressed to me in examination.My question is taken from The ZooKeeper Service topic in section ZooKeeper, Sqoop and Cassandra of Hadoop

Zookeeper essentially mirrors the _______ functionality exposed in the Linux kernel.(a) iread(b) inotify(c) iwrite(d) icountI have been asked this question in semester exam.I'd like to ask this question from The ZooKeeper Service in section ZooKeeper, Sqoop and Cassandra of Hadoop

The underlying client-server protocol has changed in version _______ of ZooKeeper.(a) 2.0.0(b) 3.0.0(c) 4.0.0(d) 6.0.0This question was addressed to me in examination.I'm obligated to ask this question of Introduction to Zookeeper in section ZooKeeper, Sqoop and Cassandra of Hadoop

When a _______ is triggered the client receives a packet saying that the znode has changed.(a) event(b) watch(c) row(d) valueThe question was posed to me during an interview.My question is based upon Introduction to Zookeeper in portion ZooKeeper, Sqoop and Cassandra of Hadoop

Which of the guarantee is provided by Zookeeper?(a) Interactivity(b) Flexibility(c) Scalability(d) ReliabilityI have been asked this question by my college professor while I was bunking the class.My query is from Introduction to Zookeeper topic in section ZooKeeper, Sqoop and Cassandra of Hadoop

ZooKeeper is especially fast in ___________ workloads.(a) write(b) read-dominant(c) read-write(d) none of the mentionedThis question was posed to me during an interview for a job.My doubt stems from Introduction to Zookeeper topic in portion ZooKeeper, Sqoop and Cassandra of Hadoop