What does “Velocity” in Big Data mean?

_______________ refers to the accuracy and correctness of the data relative to a particular use

Consider the following statements: Statement 1: Viscosity refers to the connectedness of big data. Statement 2: Volatility refers to the rate of data loss and stable lifetime of data

______________ is a programming model and an associated implementation for processing and generating large data sets

_______________is an open source software framework for big data. It has two basic parts: HDFS and Map Reduce.

The fundamental idea of __________________ is to split up the functionalities of resource management and job scheduling/monitoring into separate daemons. The idea is to have a global Resource Manager (RM) and per-application Application Master (AM). An application is either a single job or a DAG of jobs.

____________is a highly reliable distributed coordination kernel , which can be used for distributed locking, configuration management, leadership election, and work queues etc.

______________ is an open source stream processing software platform developed by the Apache Software Foundation written in Scala and Java.

True or False ? NoSQL databases are non-tabular databases and store data differently than relational tables. NoSQL databases come in a variety of types based on their data model. The main types are document, key-value, wide-column, and graph. They provide flexible schemas and scale easily with large amounts of data and high user loads.

_______________works as a master server that manages the file system namespace and basically regulates access to these files from clients, and it also keeps track of where the data is on the Data Nodes and where the blocks are distributed essentially.

When a client contacts the name node for accessing a file, the name node responds with

The namenode knows that the datanode is active using a mechanism known as

For reading/writing data to/from HDFS, clients first connect to ______________

True or False ? HDFS performs replication, although it results in data redundancy?

Consider the following statements: Statement 1: Task Tracker is hosted inside the master and it receives the job execution request from the client. Statement 2: Job tracker is the MapReduce component on the slave machine as there are multiple slave machines.

Consider the following statements: Statement 1: MapReduce is a programming model and an associated implementation for processing and generating large data sets. Statement 2: Users specify a map function that processes a key/value pair to generate a set of intermediate key/value pairs, and a reduce function that merges all intermediate values associated with the same intermediate key

Point out the correct statement in context of YARN:

Apache Hadoop YARN stands for:

Consider the pseudo-code for MapReduce's WordCount example (not shown here). Let's now assume that you want to determine the average length of all the words in a text file. Which part of the pseudo-code do you need to adapt?

Consider the following statements in the context of Spark: Statement 1: Spark improves efficiency through in-memory computing primitives and general computation graphs. Statement 2: Spark improves usability through high-level APIs in Java, Scala, Python and also provides an interactive shell

True or False ? Resilient Distributed Datasets (RDDs) are fault-tolerant and immutable

In Spark, a ______________________is a read-only collection of objects partitioned across a set of machines that can be rebuilt if a partition is lost.

Given the following definition about the join transformation in Apache Spark: def join[W](other: RDD[(K, W)]): RDD[(K, (V, W))] Where join operation is used for joining two datasets. When it is called on datasets of type (K, V) and (K, W), it returns a dataset of (K, (V, W)) pairs with all pairs of elements for each key. Output the result of joinrdd, when the following code is run. val rdd1 = sc.parallelize(Seq(("m",55),("m",56),("e",57),("e",58),("s",59),("s",54))) val rdd2 = sc.parallelize(Seq(("m",60),("m",65),("s",61),("s",62),("h",63),("h",64))) val joinrdd = rdd1.join(rdd2) joinrdd.collect

True or False ? Apache Spark potentially run batch-processing programs up to 100 times faster than Hadoop MapReduce in memory, or 10 times faster on disk.

______________ leverages Spark Core fast scheduling capability to perform streaming analytics.

____________________ is a distributed graph processing framework on top of Spark.

Which of the following are the simplest NoSQL databases ?

Consider the following statements: Statement 1: Scale out means grow your cluster capacity by replacing with more powerful machines. Statement 2: Scale up means incrementally grow your cluster capacity by adding more COTS machines (Components Off the Shelf).

Point out the incorrect statement in the context of Cassandra:

In Cassandra, ________________ replication strategy treats the entire cluster as a single data center. It is suitable for a single data center and one rack. This is also called as Rack-Unaware Strategy.

In Cassandra, ____________________ is used to specify data centers and the number of replicas to place within each data center. It attempts to place replicas on distinct racks to avoid the node failure and to ensure data availability.

True or False ? A Snitch determines which data centers and racks nodes belong to. Snitches inform Cassandra about the network topology so that requests are routed efficiently and allows Cassandra to distribute replicas by grouping machines into data centers and racks.

Identify the correct choices for the given scenarios: P: All nodes see same data at any time, or reads return latest written value by any client Q: The system allows operations all the time, and operations return quickly R: The system continues to work in spite of network partitions

Consider the following statements: Statement 1: In Cassandra, during a write operation, when hinted handoff is enabled and If any replica is down, the coordinator writes to all other replicas, and keeps the write locally until down replica comes back up. Statement 2: In Cassandra, Ec2Snitch is important snitch for deployments and it is a simple snitch for Amazon EC2 deployments where all nodes are in a single region. In Ec2Snitch region name refers to data center and availability zone refers to rack in a cluster.

Cassandra uses a protocol called __________________to discover location and state information about the other nodes participating in a Cassandra cluster.

What is Eventual Consistency ?

Consider the following statements: Statement 1: When two processes are competing with each other causing data corruption, it is called deadlock Statement 2: When two processes are waiting for each other directly or indirectly, it is called race condition

Which of the following is incorrect statement ?

In Zookeeper, when a _______ is triggered the client receives a packet saying that the znode has changed.

ZooKeeper itself is intended to be replicated over a sets of hosts called ____________

Consider the Table temperature_details in Keyspace “day3” with schema as follows: temperature_details(daynum, year,month,date,max_temp) with primary key(daynum,year,month,date) There exists same maximum temperature at different hours of the same day. Choose the correct CQL query to: Alter table temperature_details to add a new column called “seasons” using map of type <varint, text> represented as <month, season>. Season can have the following values season={spring, summer, autumn, winter}. Update table temperature_details where columns daynum, year, month, date contain the following values- 4317,1955,7,26 respectively. Use the select statement to output the row after updation. Note: A map relates one item to another with a key-value pair. For each key, only one value may exist, and duplicates cannot be stored. Both the key and the value are designated with a data type.

True or False ? Apache HBase is a column-oriented, NoSQL database designed to operate on top of the Hadoop distributed file system (HDFS).

A small chunk of data residing in one machine which is part of a cluster of machines holding one HBase table is known as__________________

In HBase, what is the number of MemStore per column family ?

In HBase, __________________is a combination of row, column family, column qualifier and contains a value and a timestamp.

HBase architecture has 3 main components:

True or False ? Kafka is a high performance, real time messaging system. It is an open source tool and is a part of Apache projects

Kafka maintains feeds of messages in categories called___________________

True or False ? Statement 1: Batch Processing provides ability to process and analyze data at-rest (stored data) Statement 2: Stream Processing provides ability to ingest, process and analyze data in-motion in real or near-real-time.

What exactly Kafka key capabilities?

is a framework to import event streams from other source data systems into Kafka and export event streams from Kafka to destination data systems.

________________is a central hub to transport and store event streams in real time.

________________is a Java library to process event streams live as they occur

Which of the following tasks can be best solved using Clustering ?

Identify the correct statement in context of Regressive model of Machine Learning

___________ refers to a model that can neither model the training data nor generalize to new data

Which of the following is required by K-means clustering ?

Imagine you are working on a project which is a binary classification problem. You trained a model on training dataset and get the below confusion matrix on validation datasetBased on the above confusion matrix, choose which option(s) below will give you correct predictions ? 1. Accuracy is ~0.91 2. Misclassification rate is ~ 0.91 3. False positive rate is ~0.95 4. True positive rate is ~0.95

Identify the correct method for choosing the value of ‘k’ in k-means algorithm ?

True or False ? If your model has very low training error but high generalization error, then it is overfitting.

Identify the correct statement(s) in context of overfitting in decision trees: Statement I: The idea of Post-pruning is to grow a tree to its maximum size and then remove the nodes using a top-bottom approach. Statement II: The idea of Pre-pruning is to stop tree induction before a fully grown tree is built, that perfectly fits the training data.

Which of the following options is/are true for K-fold cross-validation ? 1. Increase in K will result in higher time required to cross validate the result. 2. Higher values of K will result in higher confidence on the cross-validation result as compared to lower value of K. 3. If K=N, then it is called Leave one out cross validation, where N is the number of observations.

Identify the correct statement(s) in context of machine learning approaches: Statement I: In supervised approaches, the target that the model is predicting is unknown or unavailable. This means that you have unlabeled data. Statement II: In unsupervised approaches the target, which is what the model is predicting, is provided. This is referred to as having labeled data because the target is labeled for every sample that you have in your data set.

True or False ? The bootstrap sampling method is a resampling method that uses random sampling with replacement.

True or False ? Statement 1: Maximum likelihood estimation is a method that determines values for the parameters of a model. The parameter values are found such that they maximize the likelihood that the process described by the model produced the data that were actually observed. Statement 2: Bagging provides an averaging over a set of possible datasets, removing noisy and non-stable parts of models.

In which of the following scenario a gain ratio is preferred over Information Gain ?

Given an attribute table shown below, which stores the basic information of attribute a, including the row identifier of instance row_id , values of attribute values (a) and class labels of instances c.Which of the following attribute will first provide the pure subset ?

Hundreds of trees can be aggregated to form a Random forest model. Which of the following is true about any individual tree in Random Forest? 1. Individual tree is built on a subset of the features 2. Individual tree is built on all the features 3. Individual tree is built on a subset of observations 4. Individual tree is built on full set of observations

Which of the following is/are true about Random Forest and Gradient Boosting ensemble methods ? 1. Both methods can be used for classification task 2. Random Forest is use for classification whereas Gradient Boosting is use for regression task 3. Random Forest is use for regression whereas Gradient Boosting is use for Classification task 4. Both methods can be used for regression task

Boosting any algorithm takes into consideration the weak learners. Which of the following is the main reason behind using weak learners ? Reason I-To prevent overfitting Reason II- To prevent underfitting

To apply bagging to regression trees which of the following is/are true in such case ? 1. We build the N regression with N bootstrap sample 2. We take the average the of N regression tree 3. Each tree has a high variance with low bias

Which of the following statement(s) is/are true in the context of Apache Spark GraphX operators ? S1: Structural operators operate on the structure of an input graph and produces a new graph. S2: Property operators modify the vertex or edge properties using a user defined map function and produces a new graph. S3: Join operators add data to graphs and produces a new graphs.

GraphX provides an API for expressing graph computation that can model the __________ abstraction

Match the following: A. Dataflow Systems i. Vertex Programs B. Graph Systems ii. Parameter Servers C. Shared Memory Systems iii. GuineaPig

is the PageRank score of vertex 'B' after the second iteration? (Without damping factor)Hint:- The basic PageRank formula is:Where, PRt+1(u)PRt+1(u) : page rank of node uu under consideration, PRt(v)PRt(v) : previous page rank of node ‘vv’ pointing to node ‘uu’ , C(v)C(v): outgoing degree of vertex ‘vv’

Which of the following statement(s) is/are true in context of Parameter Servers. S1: A machine learning framework S2: Distributes a model over multiple machines S3: It offers two operations: (i) Pull for query parts of the model (ii) Push for update parts of the model.

Identify the correct statement for Stale synchronous process (SSP): Statement 1: SSP interpolates between BSP (Bulk synchronous parallel) and Asynchronous and subsumes both. Statement 2: SSP allows usually workers to run at own pace

Which of the following are provided by spark API for graph parallel computations: i. joinVertices ii. subgraph iii. aggregateMessages

Which of the following statement(s) is/are true ? S1: Apache Spark GraphX provides the following property operators - mapVertices(), mapEdges(), mapTriplets() S2: The RDDs in Spark, depend on one or more other RDDs. The representation of dependencies in between RDDs is known as the lineage graph. Lineage graph information is used to compute each RDD on demand, so that whenever a part of persistent RDD is lost, the data that is lost can be recovered using the lineage graph information.