Featured Post

Top Questions People Ask About Pandas, NumPy, Matplotlib & Scikit-learn — Answered!

-
Image
 Whether you're a beginner or brushing up on your skills, these are the real-world questions Python learners ask most about key libraries in data science. Let’s dive in! 🐍 🐼 Pandas: Data Manipulation Made Easy 1. How do I handle missing data in a DataFrame? df.fillna( 0 ) # Replace NaNs with 0 df.dropna() # Remove rows with NaNs df.isna(). sum () # Count missing values per column 2. How can I merge or join two DataFrames? pd.merge(df1, df2, on= 'id' , how= 'inner' ) # inner, left, right, outer 3. What is the difference between loc[] and iloc[] ? loc[] uses labels (e.g., column names) iloc[] uses integer positions df.loc[ 0 , 'name' ] # label-based df.iloc[ 0 , 1 ] # index-based 4. How do I group data and perform aggregation? df.groupby( 'category' )[ 'sales' ]. sum () 5. How can I convert a column to datetime format? df[ 'date' ] = pd.to_datetime(df[ 'date' ]) ...
Post a Comment

10 Kafka Interview Questions That Recently Asked

-
10 Kafka Interview Questions That Recently Asked

Kafka Interview Questions

Here're ten interview questions that were asked during Kafka's interview.  These are useful to update your knowledge.


1. What is Kafka?

Kafka is a framework of Publisher and Subscribe. It reads messages from the Producer and allows them to read by Subscribers. It keeps store all the producer messages in the form of topics (underlying partitions). It also maintains logs.


2. What is a Consumer group?

Each consumer is part of some Consumer group. By adding more consumers to a Consumer group, you can balance the load. In general, the Consumer group reads data from the same topic. The number of partitions in a Topic always should be the same as Consumers in a particular CG (consumer group).


3. What is Fault-Tolerance?

Each partition is replicated on multiple servers. So, when one partition is failed, the other backup will deliver. So this concept is called Fault-tolerance.


4. Can we decrease the partitions that we created?

No, you can't decrease the partitions once created. But, you can increase the partitions.


5. What is the architecture of Kafka?

The architecture is a combination of Producer, Broker, Subscriber, and Zookeeper. It can handle messages from multiple producers. It can have multiple Brokers (Sometimes it is called Kafka Broker). Zoooker oversees the Kafka cluster and has information about consumer's messages.


6. How to start Kafka Broker?

In Linux environments, you can start using $ bin/kafka-server-start.sh config/server-1.properties

$ bin/kafka-server-start.sh config/server-2.properties

So, you start Kafka server using different Server properties. Here Server-1, Server-2, and so on.


7. What is Leader Balancing in Kafka?

A partition in a Broker acts as a leader. The partitions of replicas are followers of this leader. In case of failure, the followers act as leads and deliver messages to consumers. This is called Leader balancing.


8. What is the real use of Broker?

The Broker's main functionality is to handle the storage of messages in topics.


9. What are the two main functions of Zookeeper?

  • Oversee the function of the Kafka cluster (all the nodes)
  • It commits each offset after reading by the consumer. So, in case of Consumer failure, with the help of Zooker, the consumer starts reading from the next offset (after it recovered from failure)

 10. What is the Retention period?

The amount of Time that Kafka stores messages in Topics are called the retention period. There are two types of retentions - Time-based and Storage Based


References

Comments

Post a Comment

Thanks for your message. We will get back you.

Popular posts from this blog

SQL Query: 3 Methods for Calculating Cumulative SUM

-
Image
SQL provides various constructs for calculating cumulative sums, offering flexibility and efficiency in data analysis. In this article, we explore three distinct SQL queries that facilitate the computation of cumulative sums. Each query leverages different SQL constructs to achieve the desired outcome, catering to diverse analytical needs and preferences. Using Window Functions (e.g., PostgreSQL, SQL Server, Oracle) SELECT id, value, SUM(value) OVER (ORDER BY id) AS cumulative_sum  FROM your_table; This query uses the SUM() window function with the OVER clause to calculate the cumulative sum of the value column ordered by the id column. Using Subqueries (e.g., MySQL, SQLite): SELECT t1.id, t1.value, SUM(t2.value) AS cumulative_sum FROM your_table t1 JOIN your_table t2 ON t1.id >= t2.id GROUP BY t1.id, t1.value ORDER BY t1.id; This query uses a self-join to calculate the cumulative sum. It joins the table with itself, matching rows where the id in the first table is greater than...
Read more

5 SQL Queries That Popularly Used in Data Analysis

-
Image
 Here are five popular SQL queries frequently used in data analysis. 1. SELECT with Aggregations Summarize data by calculating aggregates like counts, sums, averages, etc. SELECT department, COUNT(*) as employee_count, AVG(salary) as average_salary FROM employees GROUP BY department; 2. JOIN Operations  Combine data from multiple tables based on a related column. SELECT e.employee_id, e.name, d.department_name FROM employees e JOIN departments d ON e.department_id = d.department_id; 3. WHERE Clause for Filtering Filter records based on specified conditions. SELECT * FROM sales WHERE sale_date BETWEEN '2024-01-01' AND '2024-12-31'   AND amount > 1000; 4. ORDER BY Clause for Sorting Sort results in ascending or descending order based on one or more columns. SELECT product_name, price FROM products ORDER BY price DESC; 5. GROUP BY with HAVING Clause Group records and apply conditions to the aggregated results. SELECT department, SUM(salary) as total_salaries FROM employ...
Read more

Big Data: Top Cloud Computing Interview Questions (1 of 4)

-
Image
The below are frequently asked interview questions on Cloud computing: 1) What is the difference between Cloud and Grid? Grid: -Information service -Security Service -Data management -Execution Manageement Cloud: - Maintains up-to-date information of resources -Create VMs according to user requirement -Application deploment -User management 2) What are the different cloud standards? -Interoperability standards -Security standards -Portability Standards -Governance and Risk standards 3) What are the two different sub-systems in Cloud computing ? -Management sub system -Resource sub system 4)What is Cloud compouting? The promise of cloud computing is ubiquitous access to a broad set of applications and services, which are delivered over the network to multiple customer. 5) Why we need specialized network for Cloud services? The public Internet is the simplest choice for delivering cloud-based services. In this model, the cloud provider simply purchases Inter...
Read more