UrbanPro
Login Ask & Answer Success Stories Paid Courses Free Classes Tuition & Classes Fees Write a Review All Categories Help Center
Post your Learning Need Signup as a Tutor
✕

Popular Cities

Bangalore

Hyderabad

Delhi

Mumbai

Chennai

Pune

Kolkata

Gurgaon

Ahmedabad

Jaipur

Noida

✕

Learn Hadoop from the Best Tutors

  • Affordable fees
  • 1-1 or Group class
  • Flexible Timings
  • Verified Tutors

Book a Free Demo

Hadoop > Learn Hadoop > What is the meaning of a shared variable in Apache...
✕

Search in

What is the meaning of a shared variable in Apache Spark? What is the use of it?

Asked by Last Modified  

2 Answers

Learn Hadoop

Follow 2
Answer

Please enter your answer

Technical Lead & Archiect - Azure & Databricks, Spark,Kafka,Snowflake,Scala,Pyspark,AWS Cloud,NoSQL

Spark Shared Variables help in reducing data transfer.There two types for shared variables-Broadcast variable and Accumulators. Broadcast variable: If we have a large dataset, instead of transferring a copy of data set for each task, we can use a broadcast variable which can be copied to each node...
read more
Spark Shared Variables help in reducing data transfer.There two types for shared variables-Broadcast variable and Accumulators. Broadcast variable: If we have a large dataset, instead of transferring a copy of data set for each task, we can use a broadcast variable which can be copied to each node at one time and share the same data for each task in that node. Broadcast variable help to give a large data set to each node. First, we need to create a broadcast variable using SparkContext.broadcast and then broadcast the same to all nodes from driver program. Value method can be used to access the shared value. The broadcast variable will be used only if tasks for multiple stages use the same data. Accumulator: Spark functions used variables defined in the driver program and local copies of variables will be generated. Accumulators are shared variables which help to update variables in parallel during execution and share the results from workers to the driver. read less
Comments
Dislike Bookmark

Big Data Architect

Normally, when a function passed to a Spark operation (such as map or reduce) is executed on a remote cluster node, it works on separate copies of all the variables used in the function. These variables are copied to each machine, and no updates to the variables on the remote machine are propagated back...
read more
Normally, when a function passed to a Spark operation (such as map or reduce) is executed on a remote cluster node, it works on separate copies of all the variables used in the function. These variables are copied to each machine, and no updates to the variables on the remote machine are propagated back to the driver program. Supporting general, read-write shared variables across tasks would be inefficient. However, Spark does provide two limited types of shared variables for two common usage patterns: broadcast variables and accumulators. Broadcast variables allow the programmer to keep a read-only variable cached on each machine rather than shipping a copy of it with tasks. They can be used, for example, to give every node a copy of a large input dataset in an efficient manner. Spark also attempts to distribute broadcast variables using efficient broadcast algorithms to reduce communication cost. Accumulators are variables that are only “added” to through an associative operation and can therefore be efficiently supported in parallel. They can be used to implement counters (as in MapReduce) or sums. Spark natively supports accumulators of numeric types, and programmers can add support for new types. If accumulators are created with a name, they will be displayed in Spark’s UI. This can be useful for understanding the progress of running stages (NOTE: this is not yet supported in Python). read less
Comments
Dislike Bookmark

Related Questions

Can anyone suggest about Hadoop?
Hadoop is good but it depends on your experience. If you don't know basic java, linux, shell scripting. Hadoop is not beneficial for you.
Ajay
What is big data and Hadoop?
Big data refers to extremely large datasets that cannot be easily managed or analyzed using traditional data processing tools. Hadoop is an open-source framework designed to store and process big data...
Parini
0 0
5
Which is better for the future Hadoop or cloud computing for a fresher?
Hadoop and Big Data
Asif
0 0
6
Hello, I am Ali from Hyderabad, and I am into Telecom field as a Network Performance Engineer from the past 3 years, and as I don't find any growth in Telecom Field due to stability I am thinking to switch into IT field. And so far whatever I have researched I found Big Data is the demand in IT sector. 1. Can a non-IT guy with no programming/coding knowledge can step into Big Data? 2. How much scope does Big Data have or for how much years can we except Big Data around? 3. If I opt the course into your institute, will there be any real-time exposure during the course? 4. Can I easily get a job into Big Data as I am a non-IT person? And any experts or who have already taken course from any Institution and got helped in getting placements, please do suggest me which would be the best.
Hello Ali, We are from Sgraph Infotech, Bangalore. Bigdata Hadoop is Very good Technology in current market. You can find openings in all the MNC companies. For Bigdata you should have little bit of core...
Ali
Hi everyone, What is Hadoop /bigdata and what is required qualification and work experience background for Hadoop/bigdata?
Hadoop is the core platform for structuring Big Data, and solves the problem of formatting it for subsequent analytics purposes. Hadoop uses a distributed computing architecture consisting of multiple...
Priya

Now ask question in any of the 1000+ Categories, and get Answers from Tutors and Trainers on UrbanPro.com

Ask a Question

Related Lessons

Use of Piggybank and Registration in Pig
What is a Piggybank? Piggybank is a jar and its a collection of user contributed UDF’s that is released along with Pig. These are not included in the Pig JAR, so we have to register them manually...
S

Sachin Patil

0 0
0
How Big Data Hadoop and its importance for an enterprise?
In IT phrasing, Big Data is characterized as a collection of data sets (Hadoop), which are so mind boggling and large that the data cannot be easily captured, stored, searched, shared, analyzed or visualized...

Prwatech

1 0
0
Hadoop v/s Spark
1. Introduction to Apache Spark: It is a framework for performing general data analytics on distributed computing cluster like Hadoop.It provides in memory computations for increase speed and data process...

Gopal Raj

0 0
0
13 Things Every Data Scientist Must Know Today
We have spent close to a decade in data science & analytics now. Over this period, We have learnt new ways of working on data sets and creating interesting stories. However, before we could succeed,...

SV Tech Soft

0 0
0
Lets look at Apache Spark's Competitors. Who are the top Competitors to Apache Spark today.
Apache Spark is the most popular open source product today to work with Big Data. More and more Big Data developers are using Spark to generate solutions for Big Data problems. It is the de-facto standard...
B

Biswanath Banerjee

1 0
0

Recommended Articles

Growth and Career Prospects in Big Data

Big data is a phrase which is used to describe a very large amount of structured (or unstructured) data. This data is so “big” that it gets problematic to be handled using conventional database techniques and software.  A Big Data Scientist is a business employee who is responsible for handling and statistically evaluating...

Read full article >

Some Popular IT Courses in Current Market

In the domain of Information Technology, there is always a lot to learn and implement. However, some technologies have a relatively higher demand than the rest of the others. So here are some popular IT courses for the present and upcoming future: Cloud Computing Cloud Computing is a computing technique which is used...

Read full article >

Learn Hadoop and Big Data

Hadoop is a framework which has been developed for organizing and analysing big chunks of data for a business. Suppose you have a file larger than your system’s storage capacity and you can’t store it. Hadoop helps in storing bigger files than what could be stored on one particular server. You can therefore store very,...

Read full article >

Why Should you Become a Data Scientist

We have already discussed why and how “Big Data” is all set to revolutionize our lives, professions and the way we communicate. Data is growing by leaps and bounds. The Walmart database handles over 2.6 petabytes of massive data from several million customer transactions every hour. Facebook database, similarly handles...

Read full article >

Find Hadoop near you
Hadoop in Hyderabad
Hadoop in Bangalore
Hadoop in Chennai
Hadoop in Pune
Hadoop in Mumbai
Hadoop in Ahmedabad
Hadoop in Gurgaon
Hadoop in Noida

Looking for Hadoop ?

Learn from the Best Tutors on UrbanPro

Are you a Tutor or Training Institute?

Join UrbanPro Today to find students near you
X

Looking for Hadoop Classes?

The best tutors for Hadoop Classes are on UrbanPro

  • Select the best Tutor
  • Book & Attend a Free Demo
  • Pay and start Learning

Learn Hadoop with the Best Tutors

The best Tutors for Hadoop Classes are on UrbanPro

This website uses cookies

We use cookies to improve user experience. Choose what cookies you allow us to use. You can read more about our Cookie Policy in our Privacy Policy

Accept All
Decline All

UrbanPro.com is India's largest network of most trusted tutors and institutes. Over 55 lakh students rely on UrbanPro.com, to fulfill their learning requirements across 1,000+ categories. Using UrbanPro.com, parents, and students can compare multiple Tutors and Institutes and choose the one that best suits their requirements. More than 7.5 lakh verified Tutors and Institutes are helping millions of students every day and growing their tutoring business on UrbanPro.com. Whether you are looking for a tutor to learn mathematics, a German language trainer to brush up your German language skills or an institute to upgrade your IT skills, we have got the best selection of Tutors and Training Institutes for you. Read more

ThinkVidya Learning Pvt Ltd © 2010-2025 All Rights Reserved