98 + Interview Questions in Replication Concepts in Mongodb Page 2 InterviewSolution

51.	__________ operations cannot guarantee that the data files do not change.(a) db.lockl()(b) db.synclock()(c) db.fsyncUnlock()(d) secondaryI got this question in unit test.The origin of the question is Master Slave Replication topic in division Replication Concepts, Processes and Replication Set of MongoDB
Answer» The CORRECT choice is (c) db.fsyncUnlock() To elaborate: As a RESULT, do not USE these methods to ENSURE CONSISTENCY for the purposes of creating backups.

Discussion

52.	_______ may block reads, including those necessary to verify authentication.(a) db.lockall()(b) db.fsyncLock()(c) db,lockreads()(d) none of the mentionedThis question was posed to me during an internship interview.My doubt is from Master Slave Replication topic in division Replication Concepts, Processes and Replication Set of MongoDB
Answer» The correct answer is (b) db.fsyncLock() To EXPLAIN I WOULD say: Such READS are necessary to establish new CONNECTIONS to a mongod that ENFORCES authorization checks.

Discussion

53.	Point out the wrong statement.(a) Clients will not distribute reads with the appropriate read preference to hidden members(b) Hidden members cannot vote in replica set elections(c) If you stop a voting hidden member, ensure that the set has an active majority or the primary will step down(d) None of the mentionedI got this question during an interview.Question is from Master Slave Replication in portion Replication Concepts, Processes and Replication Set of MongoDB
Answer» Correct choice is (b) Hidden members cannot VOTE in REPLICA SET ELECTIONS The explanation: Hidden members may vote in replica set elections

Discussion

54.	Which of the following members should be hidden?(a) Delayed(b) Hidden(c) Primary(d) All of the mentionedI have been asked this question by my school teacher while I was bunking the class.This intriguing question originated from Master Slave Replication in section Replication Concepts, Processes and Replication Set of MongoDB
Answer» Correct answer is (a) Delayed Best explanation: Use hidden MEMBERS for DEDICATED TASKS such as reporting and backups.

Discussion

55.	The db.________ method does not display hidden members.(a) isPrima ry()(b) isMaster()(c) Master()(d) none of the mentionedI had been asked this question in examination.The question is from Read and Write Semantics topic in division Replication Concepts, Processes and Replication Set of MongoDB
Answer» Correct OPTION is (B) ISMASTER() Easy explanation: Hidden members, HOWEVER, may vote in elections.

Discussion

56.	A second data center hosts one priority 0 member that cannot become ___________(a) primary(b) write(c) view(d) SecondaryThe question was asked in an online interview.Asked question is from Read and Write Semantics topic in section Replication Concepts, Processes and Replication Set of MongoDB
Answer» The correct OPTION is (a) primary The explanation: A priority 0 member can function as a STANDBY.

Discussion

57.	A ______ member maintains a copy of the primary’s data set but is invisible to client applications.(a) primary(b) delayed(c) hidden(d) none of the mentionedThe question was posed to me during an interview for a job.This interesting question is from Read and Write Semantics topic in division Replication Concepts, Processes and Replication Set of MongoDB
Answer» RIGHT choice is (C) hidden To ELABORATE: Hidden members are good for workloads with different usage PATTERNS from the other members in the replica set.

Discussion

58.	Point out the correct statement.(a) Elections does not occur when the primary becomes unavailable and the replica set members autonomously select a new primary(b) A priority 1 member maintains a copy of the data set, accepts read operations, and votes in elections(c) In a two-member replica set, in one data center hosts the primary and a secondary.(d) None of the mentionedI got this question in examination.Question is from Read and Write Semantics topic in portion Replication Concepts, Processes and Replication Set of MongoDB
Answer» CORRECT choice is (a) Elections does not occur when the primary BECOMES unavailable and the replica set members autonomously select a new primary To explain: Configure a priority 0 MEMBER to prevent secondaries from becoming primary, which is particularly useful in multi-data center deployments.

Discussion

59.	A priority __ member is a secondary that cannot become primary.(a) 0(b) 1(c) 2(d) None of the mentionedI got this question in an interview.This intriguing question comes from Read and Write Semantics in portion Replication Concepts, Processes and Replication Set of MongoDB
Answer» Right ANSWER is (a) 0 Easy EXPLANATION: Priority 0 MEMBERS cannot TRIGGER elections.

Discussion

60.	A rollback reverts _______ operations on a former primary when the member rejoins the replica set after a failover.(a) read(b) write(c) view(d) secondaryThis question was addressed to me by my school teacher while I was bunking the class.The query is from Read and Write Semantics topic in division Replication Concepts, Processes and Replication Set of MongoDB
Answer» Right answer is (b) write To EXPLAIN I WOULD say: The replica set RECOVERS from the loss of a primary by holding an election.

Discussion

61.	Point out the wrong statement.(a) Administrators must apply or discard rollback data manually(b) Network partitions could not prevent the set from being able to form a majority(c) Replica sets remove “rollback” data when needed without intervention(d) None of the mentionedI got this question during an online exam.Question is from Read and Write Semantics in section Replication Concepts, Processes and Replication Set of MongoDB
Answer» Right choice is (b) NETWORK PARTITIONS could not prevent the set from being able to form a majority To elaborate: When a ROLLBACK does occur, it is often the result of a network partition.

Discussion

62.	The __________ of a replica set affects the outcome of failover situations.(a) deployment(b) architecture(c) structure(d) all of the mentionedI had been asked this question in my homework.I'm obligated to ask this question of Read and Write Semantics in portion Replication Concepts, Processes and Replication Set of MongoDB
Answer» The correct answer is (a) deployment Explanation: To SUPPORT EFFECTIVE failover, ENSURE that ONE facility can elect a primary if needed.

Discussion

63.	Use ______ to apply the changes to the new primary after rollback.(a) mongostore(b) mongorestore(c) restore(d) none of the mentionedThe question was asked during an interview.Origin of the question is Replica Set High Availability topic in division Replication Concepts, Processes and Replication Set of MongoDB
Answer» Correct CHOICE is (b) mongorestore The explanation is: The mongorestore program writes DATA from a BINARY database dump created by MONGODUMP to a MONGODB instance.

Discussion

64.	_________ is used to read the contents of the rollback files.(a) bsondumpdata(b) bsondp(c) bsondump(d) none of the mentionedI got this question in an online interview.Question is from Replica Set High Availability in division Replication Concepts, Processes and Replication Set of MongoDB
Answer» The CORRECT answer is (C) bsondump Explanation: The bsondump converts BSON FILES into human-readable formats, including JSON.

Discussion

65.	Point out the correct statement.(a) A rollback does not occur if the write operations replicate to another member of the replica set before the primary steps down(b) Secondaries that can not keep up with the throughput of operations on the former primary, decrease the size and impact of the rollback(c) Fault tolerance is an effect of replica set size, but the relationship is not direct(d) None of the mentionedThe question was posed to me in an internship interview.My question is from Replica Set High Availability in portion Replication Concepts, Processes and Replication Set of MongoDB
Answer» Correct OPTION is (a) A rollback does not occur if the WRITE operations replicate to another member of the replica set before the primary steps down The EXPLANATION is: When a rollback does occur, ADMINISTRATORS must decide whether to apply or IGNORE the rollback data.

Discussion

66.	The names of rollback files have the following form.(a) ...bson.(b) ...bson.(c) ...json.(d) None of the mentionedThis question was posed to me in a national level competition.This key question is from Replica Set High Availability topic in division Replication Concepts, Processes and Replication Set of MongoDB
Answer» Correct choice is (a) ...bson. The explanation is: Administrators must apply ROLLBACK data manually after the MEMBER completes the rollback and RETURNS to secondary status.

Discussion

67.	MongoDB writes the rollback data to BSON files in the rollback/ folder under the database’s ________ directory.(a) dbPath(b) logPath(c) dataPath(d) all of the mentionedThis question was posed to me during an internship interview.Query is from Replica Set High Availability topic in section Replication Concepts, Processes and Replication Set of MongoDB
Answer» Right choice is (a) dbPath For explanation I WOULD say: The storage.dbPath SETTING is available only for MONGOD.

Discussion

68.	Sometimes the failover process may require a ____________ during operation.(a) savepoint(b) rollback(c) commit(d) none of the mentionedThis question was addressed to me in an online quiz.The above asked question is from Replica Set High Availability topic in division Replication Concepts, Processes and Replication Set of MongoDB
Answer» Right choice is (b) rollback Easiest explanation: A rollback reverts write OPERATIONS on a former primary when the MEMBER REJOINS its replica SET after a failover.

Discussion

69.	Failover allows a ________ member to become primary if primary is unavailable.(a) Hidden(b) Primary(c) ViewState(d) SecondaryThis question was posed to me in a job interview.This question is from Replica Set High Availability in division Replication Concepts, Processes and Replication Set of MongoDB
Answer» Right ANSWER is (d) Secondary Easiest EXPLANATION: Replica SET MEMBERS keep the same data set but are otherwise independent.

Discussion

70.	Point out the wrong statement.(a) When the primary rejoins the set as a secondary, it reverts, or “rolls back,” its write operations to maintain database consistency with the other members(b) A rollback is necessary only if the primary had accepted write operations that the secondaries had not successfully replicated before the primary stepped down(c) MongoDB attempts for rollbacks, which should be rare(d) None of the mentionedI got this question in an internship interview.My query is from Replica Set High Availability in division Replication Concepts, Processes and Replication Set of MongoDB
Answer» The correct answer is (C) MongoDB ATTEMPTS for rollbacks, which should be rare To elaborate: When a rollback does occur, it is OFTEN the result of a network partition.

Discussion

71.	Replica sets provide high availability using automatic ________(a) failover(b) replication(c) failure(d) all of the mentionedI got this question in an internship interview.I want to ask this question from Replica Set High Availability topic in portion Replication Concepts, Processes and Replication Set of MongoDB
Answer» RIGHT CHOICE is (a) failover The explanation: Failover, in most situations does not REQUIRE MANUAL intervention.

Discussion

72.	What should be the priority of member to prevent them from becoming primary?(a) 0(b) 1(c) 2(d) 3I have been asked this question in final exam.I need to ask this question from Replica Set Deployment Architectures topic in division Replication Concepts, Processes and Replication Set of MongoDB
Answer» Correct OPTION is (a) 0 To explain I would say: Always ensure that the MAIN facility is able to ELECT a primary.

Discussion

73.	_________ member is used to support dedicated functions, such as backup or reporting.(a) Hidden(b) Primary(c) ViewState(d) None of the mentionedI had been asked this question in an interview.The query is from Replica Set Deployment Architectures topic in section Replication Concepts, Processes and Replication Set of MongoDB
Answer» Correct answer is (a) Hidden To explain I WOULD say: Delayed members can also SUPPORT DEDICATED FUNCTIONS.

Discussion

74.	To protect your data if your main data center fails, keep at least _______ member in an alternate data center.(a) one(b) two(c) three(d) none of the mentionedThe question was asked in homework.Question is taken from Replica Set Deployment Architectures topic in portion Replication Concepts, Processes and Replication Set of MongoDB
Answer» The correct option is (a) one To EXPLAIN I would SAY: ALWAYS add new members before the current DEMAND SATURATES the capacity of the set.

Discussion

75.	Without a primary, a replica set cannot accept ________ operations.(a) read(b) write(c) read write(d) all of the mentionedThe question was asked during an internship interview.I'm obligated to ask this question of Replica Set Deployment Architectures topic in division Replication Concepts, Processes and Replication Set of MongoDB
Answer» RIGHT choice is (B) write For explanation: Arbiters do not KEEP a COPY of the DATA.

Discussion

76.	Point out the correct statement.(a) Removing a member to the replica set does not always increase the fault tolerance(b) The secondary is the only member in the replica set that receives write operations(c) Fault tolerance is an effect of replica set size, but the relationship is not direct(d) None of the mentionedI had been asked this question in a job interview.Asked question is from Replica Set Deployment Architectures topic in portion Replication Concepts, Processes and Replication Set of MongoDB
Answer» Right choice is (C) Fault tolerance is an effect of replica set size, but the relationship is not direct Easiest explanation: Additional members can PROVIDE SUPPORT for DEDICATED functions, such as backups or REPORTING.

Discussion

77.	_________ for a replica set is the number of members that can become unavailable and still leave enough members in the set to elect a primary.(a) Fault tolerance(b) Reliability(c) Security(d) None of the mentionedI got this question in final exam.The above asked question is from Replica Set Deployment Architectures topic in chapter Replication Concepts, Processes and Replication Set of MongoDB
Answer» Right choice is (a) Fault tolerance The explanation: In other WORDS, it is the DIFFERENCE between the number of members in the set and the MAJORITY NEEDED to elect a primary.

Discussion

78.	The standard replica set deployment for production system is a ___-member replica set.(a) two(b) three(c) four(d) fiveThis question was posed to me by my school principal while I was bunking the class.The query is from Replica Set Deployment Architectures in division Replication Concepts, Processes and Replication Set of MongoDB
Answer» The correct ANSWER is (b) three To explain I would say: AVOID complexity when POSSIBLE, but let your application requirements dictate the ARCHITECTURE.

Discussion

79.	Point out the wrong statement.(a) Even number of members ensures that the replica set is always able to elect a primary(b) Arbiters do not store a copy of the data and require fewer resources(c) You may run an arbiter on an application server or other shared process(d) None of the mentionedThis question was addressed to me in an internship interview.This intriguing question originated from Replica Set Deployment Architectures in chapter Replication Concepts, Processes and Replication Set of MongoDB
Answer» Right option is (a) Even NUMBER of members ensures that the replica set is always able to ELECT a primary Easy explanation: If you have an even number of members, ADD an ARBITER to get an odd number.

Discussion

80.	If the current primary becomes unavailable, the replica set holds an ______ to choose which of the secondaries becomes the new primary.(a) election(b) replication(c) clasification(d) none of the mentionedThe question was asked by my school principal while I was bunking the class.Question is from Replica Set Members topic in division Replication Concepts, Processes and Replication Set of MongoDB
Answer» The CORRECT answer is (a) election Best EXPLANATION: A SECONDARY can become a PRIMARY.

Discussion

81.	The architecture of a replica set affects the set’s _________ and capability.(a) scalability(b) capacity(c) performance(d) all of the mentionedThe question was posed to me in exam.This intriguing question originated from Replica Set Deployment Architectures topic in section Replication Concepts, Processes and Replication Set of MongoDB
Answer» RIGHT option is (b) capacity Explanation: REPLICA sets provide REDUNDANCY and fault TOLERANCE.

Discussion

82.	Which of the following may be non-voting or priority 0?(a) center(b) secondary(c) primary(d) none of the mentionedThe question was posed to me by my college professor while I was bunking the class.The query is from Replica Set Members in portion Replication Concepts, Processes and Replication Set of MongoDB
Answer» The correct option is (B) secondary Explanation: All MEMBERS of the REPLICA SET can ACCEPT read operations.

Discussion

83.	A replica set can have up to ______ members but only 7 voting members.(a) 10(b) 30(c) 50(d) 70I got this question in an interview for job.Question is from Replica Set Members topic in chapter Replication Concepts, Processes and Replication Set of MongoDB
Answer» CORRECT choice is (d) 70 For explanation: In PREVIOUS VERSIONS, REPLICA sets can have up to 12 members.

Discussion

84.	_________ play a role in the elections that select a primary if the current primary is unavailable.(a) Arbiters(b) Replicators(c) Loggers(d) None of the mentionedI got this question in a job interview.This intriguing question comes from Replica Set Members in portion Replication Concepts, Processes and Replication Set of MongoDB
Answer» RIGHT CHOICE is (a) ARBITERS Easy EXPLANATION: Arbiters do not keep a copy of the DATA.

Discussion

85.	Point out the wrong statement.(a) The minimum requirements for a replica set are: A primary, a secondary, and an arbiter(b) The primary is the only member in the replica set that receives write operations(c) Most deployments, however, will keep three members that store data: A primary and two secondary members(d) None of the mentionedThe question was posed to me by my college professor while I was bunking the class.I want to ask this question from Replica Set Members in portion Replication Concepts, Processes and Replication Set of MongoDB
Answer» The correct option is (d) None of the mentioned For explanation I WOULD say: SECONDARY members replicate this OPLOG and apply the operations to their DATA SETS.

Discussion

86.	_________ replicate operations from the primary to maintain an identical data set.(a) center(b) secondary(c) primary(d) none of the mentionedI have been asked this question in an international level competition.Origin of the question is Replica Set Members topic in section Replication Concepts, Processes and Replication Set of MongoDB
Answer» The correct choice is (B) secondary Explanation: Secondaries may have additional CONFIGURATIONS for SPECIAL usage profiles.

Discussion

87.	Which of the member receives all write operations?(a) center(b) secondary(c) primary(d) none of the mentionedI have been asked this question in an internship interview.I'd like to ask this question from Replica Set Members topic in portion Replication Concepts, Processes and Replication Set of MongoDB
Answer» The correct OPTION is (C) PRIMARY To elaborate: The primary ACCEPTS all write operations from clients.

Discussion

88.	When a primary does not communicate with the other members of the set for more than ____ seconds, the replica set will attempt to select another member to become the new primary.(a) 10(b) 20(c) 30(d) None of the mentionedI had been asked this question in final exam.This key question is from Replication in MongoDB in chapter Replication Concepts, Processes and Replication Set of MongoDB
Answer» The correct OPTION is (a) 10 The explanation is: The FIRST secondary that receives a majority of the votes becomes primary.

Discussion

89.	Point out the wrong statement.(a) Replication provides scalability and increases data redundancy(b) A replica set in MongoDB is a group of mongod processes that provide redundancy and high availability(c) You can also maintain an arbiter as part of a replica set(d) None of the mentionedI got this question in homework.Enquiry is from Replica Set Members in section Replication Concepts, Processes and Replication Set of MongoDB
Answer» CORRECT choice is (a) Replication provides scalability and INCREASES data REDUNDANCY The explanation: Data redundancy is reduced by REPLICATING the COPIES of data.

Discussion

90.	How many types of members exist in replica set?(a) 1(b) 2(c) 3(d) 4The question was posed to me in an interview for internship.My doubt is from Replica Set Members topic in division Replication Concepts, Processes and Replication Set of MongoDB
Answer» The correct OPTION is (B) 2 To ELABORATE: There are two MEMBERS in replica set-primary and SECONDARY.

Discussion

91.	An arbiter will always be an arbiter whereas a primary may step down and become a secondary and a _________ may become the primary during an election.(a) center(b) secondary(c) primary(d) none of the mentionedThis question was addressed to me in an online interview.I would like to ask this question from Replication in MongoDB topic in division Replication Concepts, Processes and Replication Set of MongoDB
Answer» CORRECT choice is (b) secondary To explain: If your replica set has an even number of MEMBERS, add an arbiter to obtain a majority of VOTES in an ELECTION for primary.

Discussion

92.	You may add an extra mongod instance to a replica set as an __________(a) arbiter(b) replicator(c) additor(d) all of the mentionedI got this question during an interview.Origin of the question is Replication in MongoDB topic in chapter Replication Concepts, Processes and Replication Set of MongoDB
Answer» Correct CHOICE is (a) arbiter To explain: ARBITERS do not maintain a DATA SET.

Discussion

93.	To support replication, the primary records all changes to its data sets in its _______(a) oplog(b) adlog(c) log(d) none of the mentionedI have been asked this question in an interview for internship.My question is based upon Replication in MongoDB topic in chapter Replication Concepts, Processes and Replication Set of MongoDB
Answer» RIGHT CHOICE is (a) oplog Explanation: If the primary is unavailable, the replica set will ELECT a secondary to be primary.

Discussion

94.	Point out the wrong statement.(a) In all cases, you can use replication to increase read capacity(b) Clients have the ability to send read and write operations to different servers(c) You can also maintain copies in different data centers to increase the locality and availability of data for distributed applications(d) None of the mentionedThe question was posed to me in semester exam.This key question is from Replication in MongoDB in portion Replication Concepts, Processes and Replication Set of MongoDB
Answer» Right ANSWER is (a) In all CASES, you can USE REPLICATION to increase read capacity The EXPLANATION is: In some cases, you can use replication to increase read capacity.

Discussion

95.	A replica set can have only ________ primary.(a) One(b) Two(c) Three(d) All of the mentionedThe question was asked in examination.My doubt is from Replication in MongoDB topic in division Replication Concepts, Processes and Replication Set of MongoDB
Answer» Right choice is (a) One Easiest explanation: The secondaries replicate the PRIMARY’s oplog and apply the OPERATIONS to their DATA sets such that the secondaries’ data sets reflect the primary’s data SET.

Discussion

96.	All other instances, secondaries, apply operations from the _________ so that they have the same data set.(a) center(b) secondary(c) primary(d) none of the mentionedThe question was asked in a national level competition.I'm obligated to ask this question of Replication in MongoDB topic in portion Replication Concepts, Processes and Replication Set of MongoDB
Answer» Correct CHOICE is (c) PRIMARY To explain I WOULD SAY: The primary accepts all write operations from clients.

Discussion

97.	Point out the wrong statement.(a) Replication provides redundancy and increases data availability(b) Replication allows you to recover from hardware failure and service interruptions(c) With multiple copies of data on different database servers, replication protects a database from the loss of a single server(d) None of the mentionedThe question was posed to me in an interview for job.The doubt is from Replication in MongoDB topic in section Replication Concepts, Processes and Replication Set of MongoDB
Answer» CORRECT option is (d) None of the mentioned To EXPLAIN: With additional COPIES of the data, you can dedicate one to DISASTER recovery, reporting, or backup.

Discussion

98.	A _______ set is a group of mongod instances that host the same data set.(a) copy(b) sorted(c) radii(d) replicaI have been asked this question in an international level competition.The origin of the question is Replication in MongoDB in chapter Replication Concepts, Processes and Replication Set of MongoDB
Answer» CORRECT answer is (d) replica The explanation: ONE MONGOD, the PRIMARY, receives all write OPERATIONS.

Discussion

Explore topic-wise InterviewSolutions in .

The db.________ method does not display hidden members.(a) isPrima ry()(b) isMaster()(c) Master()(d) none of the mentionedI had been asked this question in examination.The question is from Read and Write Semantics topic in division Replication Concepts, Processes and Replication Set of MongoDB

A second data center hosts one priority 0 member that cannot become ___________(a) primary(b) write(c) view(d) SecondaryThe question was asked in an online interview.Asked question is from Read and Write Semantics topic in section Replication Concepts, Processes and Replication Set of MongoDB

A priority __ member is a secondary that cannot become primary.(a) 0(b) 1(c) 2(d) None of the mentionedI got this question in an interview.This intriguing question comes from Read and Write Semantics in portion Replication Concepts, Processes and Replication Set of MongoDB

_________ is used to read the contents of the rollback files.(a) bsondumpdata(b) bsondp(c) bsondump(d) none of the mentionedI got this question in an online interview.Question is from Replica Set High Availability in division Replication Concepts, Processes and Replication Set of MongoDB

What should be the priority of member to prevent them from becoming primary?(a) 0(b) 1(c) 2(d) 3I have been asked this question in final exam.I need to ask this question from Replica Set Deployment Architectures topic in division Replication Concepts, Processes and Replication Set of MongoDB

A replica set can have up to ______ members but only 7 voting members.(a) 10(b) 30(c) 50(d) 70I got this question in an interview for job.Question is from Replica Set Members topic in chapter Replication Concepts, Processes and Replication Set of MongoDB

How many types of members exist in replica set?(a) 1(b) 2(c) 3(d) 4The question was posed to me in an interview for internship.My doubt is from Replica Set Members topic in division Replication Concepts, Processes and Replication Set of MongoDB

You may add an extra mongod instance to a replica set as an __________(a) arbiter(b) replicator(c) additor(d) all of the mentionedI got this question during an interview.Origin of the question is Replication in MongoDB topic in chapter Replication Concepts, Processes and Replication Set of MongoDB

A replica set can have only ________ primary.(a) One(b) Two(c) Three(d) All of the mentionedThe question was asked in examination.My doubt is from Replication in MongoDB topic in division Replication Concepts, Processes and Replication Set of MongoDB