Course Name :- Developing Distributed Applications Using ZooKeeper
Module 1 :- Introduction Zookeeper
Question 1 : What is NOT a benefit that distributed systems offer over centralized systems?
- Price to achieve redundancy
- Redundancy
- Ease of developing your own coordination service
- Scalability
Question 2: A ZooKeeper client can perform a read operation from any server in the ensemble, but a write operation must go through the ZooKeeper leader and requires a majority consensus to succeed. True or false?
- False
- True
Question 3 : What’s the benefit of running ZooKeeper in Standalone mode over Replicated mode?
- Cheaper
- Resilience
- Simpler testing and learning
- High availability
Module 2 :- The Zoookeeper Data Model
Question 1: Which of the following statements is true?
- A client reading the data stored at a znode can receive some of the data.
- ZooKeeper is designed for high-volume storage.
- The path to a znode must be expressed as a canonical, absolute, and slash-separated path.
- Znodes can be used to store data that exceeds 1MB.
Question 2 : A znode can be in multiple states at the same time. True or false?
- False
- True
Question 3 : Which of the following commands is used to retrieve the access control list of a znode?
- fetchACL
- setACL
- printACL
- getACL
Module 3 :- Programming and Advance Topics
Question 1 : In addition to the 4 letter commands, JMX can be used to monitor ZooKeeper. True or false?
- False
- True
Question 2 : Which two authentication plugins are included with ZooKeeper?
- ip and MD5
- ip and identify
- digset and MD5
- ip and digest
Question3 : What are the bindings that ZooKeeper comes with out of the box?
- Ruby and Java
- Java and C#
- Python and C
- Java and C
Developing Distributed Applications Using ZooKeeper cognitive class final Exam Answers:-
Question 1. What is the primary purpose of ZooKeeper in the Hadoop architecture?
- To provide logging support for Hadoop jobs
- To support the execution of workflows consisting of a collection of actions
- To provide a centralized coordination service for distributed applications
- To move data into HDFS
Question 2. When executing ZooKeeper in Replicated mode, a new leader can be elected if the former leader fails. True or false?
- True
- False
Question 3. Which of the following are consistency guarantees made by ZooKeeper? Select all that apply.
- Atomicity
- Reliability
- Timeliness
- Release
Question 4. ZooKeeper guarantees simultaneously consistent cross-client views. True or false?
- True
- False
Question 5. ZooKeeper can be used to implement several use cases including
- Leader Election
- Queue Management
- Configuration Management
- Locking
- All of the above
Question 6 . A ZooKeeper client can maintain a list of servers to connect to, and the client will go through its list until it successfully connects to a ZooKeeper server. True or false?
- True
- False
Question 7 : ZooKeeper Watches can be used to
- Watch for failed MapReduce jobs
- Watch for changes to Hadoop configuration
- Watch for changes in the Hadoop Filesystem (HDFS)
- None of the above
Question 8 . If you want to be notified of a change in a ZooKeeper znode, you should use
- The ZooKeeper getData() method
- The ZooKeeper sync() method
- The ZooKeeper callback() method
- A ZooKeeper Watch
Question 9 . In ZooKeeper, if you want a znode to be deleted when the client session ends, you should create a
- Session znode
- Ephemeral znode
- Temp znode
- Persistent znode
Question 10. Using the –s parameter when creating a znode results in a
- Ephemeral znode
- Sequential znode
- Temp znode
- Session znode
- Persistent znode
Question 11 . Which of the ‘four letter word’ commands will show you the status of a ZooKeeper server?
- stat
- dump
- conf
- cons
- ruok
Question 12 . When using the ZooKeeper Java API, what do you need to implement in order to receive Watcher notifications?
- A constructor that calls the watch method
- A class that inherits from zNode
- The process method of the Watcher interface
- None of the above
Question 13. In ZooKeeper, setting an ACL only pertains to the specific znode and is not recursive. True or false?
- True
- False
Question 14 . In ZooKeeper, what permission do you need to have in order to change the ACL on a znode?
- READ
- ADMIN
- WRITE
- DELETE
- CREATE
Question 15. You can plug in your own authentication scheme rather than using the ones provided out of the box by ZooKeeper. True or false?
- True
- False