AWS SysOps: Navigating Storage Systems Interview Questions and Answers

Introduction

This blog dissects the intricacies of managing and optimizing storage in the AWS environment. From S3 to EBS, join us to learn the interview questions and answers on efficient storage solutions in the AWS SysOps landscape.

Q1: What Is Block Storage, and How Does AWS Handle the Formatting and Provisioning of Block Storage Volumes?

Answer: Block storage in AWS refers to mountable drive storage. AWS provides unformatted drive space, and users can choose the format, block size, and other factors based on their operating system configuration. 

Typically, the formatting decisions are made by the selected Amazon Machine Image (AMI), but users have the flexibility to make their own choices. Block storage volumes are provisioned and attached to Amazon EC2 instances, and in the case of Amazon EBS, the volume's lifecycle is independent of the instance. 

The instance's operating system controls content management within block storage, with AWS having visibility into volume properties rather than individual blocks.

Q2: How Does Object Storage Differ From Block Storage Regarding Functionality and Control Within AWS?

Answer: Unlike block storage, which operates as provisioned, mountable volumes controlled by operating systems, object storage in AWS is entirely API-driven. Applications with proper credentials make API calls for reads, writes, updates, deletes, and more. This API control enables AWS to offer granular content control and increased visibility. 

Except for AWS Snowball, AWS object storage is regional, ensuring content in Amazon S3 or Amazon Glacier is automatically replicated across facilities and Availability Zones for enhanced data durability compared to single datacenter storage solutions.

Q3: What Is the Significance of Cost When Selecting and Managing Storage Options in AWS, and What Principles Govern AWS Pricing?

Answer: The third major criterion for choosing and managing storage in AWS is cost. Actual prices vary across regions, and AWS continually optimizes prices. Refer to the current pricing sheet for your chosen AWS Region. 

AWS pricing principles emphasize paying only for provisioned resources and efficient operations aligned with actual usage. This applies particularly to block storage, where operational considerations are crucial in resource provisioning.

Q4: What Does Iops Measure in the Context of Volume Performance, and How Are the Ratings Determined?

Answer: IOPS (Input/Output Operations Per Second) measures the rate of read/write actions on a volume per second. Volume ratings are based on a standard packet size, with the flexibility to choose an actual packet size based on application needs. 

Understanding the fundamentals of calculating potential IOPS is essential due to the numerous variables influencing performance, ensuring accurate assessment and optimization of storage capabilities.

Q5: How Can Amazon Cloudfront Be Used to Enhance Content Delivery Based on Request Headers?

Answer: Amazon CloudFront allows forwarding specific request headers to your origin server, providing valuable information like visitor devices or geographic location. This enables customization of cached content, catering to diverse viewer needs. 

For instance, if hosting multiple websites on a single server, configuring CloudFront to forward the Host header allows separate caching based on Host values, ensuring efficient delivery of distinct object versions.

Q6: How Does Amazon Cloudfront Handle Headers for Improved Security and Cross-Origin Request Sharing (Cors), and How Can It Be Configured?

Answer: Amazon CloudFront allows customization of headers when forwarding requests to the origin, enhancing security and facilitating Cross-Origin Request Sharing (CORS). This configuration enables validation of requests' CloudFront origin and ensures compatibility with viewers, not automatically including headers. 

CloudFront strikes a balance between security and performance optimization by disabling varying on the origin header for an improved cache hit ratio and forwarding essential headers for CORS responses.

Q7: What Protocols Does Amazon Cloudfront Support for HTTPS Connections With Custom Origin Web Servers?

Answer: Amazon CloudFront supports TLSv1.1, TLSv1.2, SSLv3, and TLSv1.0 for HTTPS connections to custom origin web servers. Users have the flexibility to select preferred protocols for communication, allowing customization for security measures. 

For instance, it's possible to exclude less secure options like SSLv3 to enhance overall security when CloudFront communicates with the origin server.

Q8: How Can You Update Cached Files in Amazon Cloudfront, and What Is the Role of Object Versioning?

Answer: Amazon CloudFront offers two options for updating cached files. One method involves implementing object versioning, where each file version on the origin server has a unique name. 

By referencing the correct version in web pages or applications, CloudFront caches the desired object version, eliminating the need to wait for expiration before serving a newer version. This allows efficient management of content changes without delays.

Q9: How Can You Gain Detailed Insights Into the Traffic Handled by Your Amazon Cloudfront Distribution, and What Are Access Logs?

Answer: To obtain detailed information about delivered or streamed traffic, you can enable access logs in Amazon CloudFront. These logs provide comprehensive records of each content request. 

CloudFront access files are automatically delivered multiple times per hour, with logs usually available within an hour of viewer requests. Enabling access logs enhances visibility, allowing you to analyze and understand the traffic patterns on your CloudFront distribution.

Q10: How Can You Monitor Data Transfer and Requests in Amazon Cloudfront, and What Information Do Usage Charts Provide?

Answer: Amazon CloudFront Usage Charts enable tracking trends in data transfer and requests (HTTP and HTTPS) for active CloudFront web distributions. These charts offer insights into usage from each CloudFront region, providing daily or hourly granularity for up to 60 days. 

The charts include totals, averages, and peak usage, offering a comprehensive view of your distribution's performance over selected time intervals.

Q11: What Is AWS Waf, and How Does It Enhance Web Application Security?

Answer: AWS WAF, a web application firewall, is crucial in identifying and thwarting malicious web requests directed at your applications. It empowers you to establish rules based on IP addresses, HTTP headers, and custom URIs. 

Through these rules, AWS WAF can effectively block, allow, or monitor (count) web requests for your web applications, providing a robust defense mechanism against potential security threats.

Q12: How Does Amazon Cloudfront Facilitate Real-Time Content Delivery, and What Technology Does It Employ for Rtmp Distributions?

Answer: Amazon CloudFront allows the creation of RTMP distributions, delivering content to end users in real-time, with viewers watching the bytes as they are delivered. 

RTMP distributions utilize Adobe's Flash Media Server 3.5 and the Real-Time Messaging Protocol (RTMP) and its variants, distinguishing them from other CloudFront distributions that use HTTP or HTTPS protocols. This enables efficient real-time streaming experiences for end users.

Q13: What Occurs When Users Request Content After Configuring Amazon Cloudfront, and How Does the Process Unfold?

Answer: After configuring Amazon CloudFront for content delivery, when users request objects:

• The user accesses the website or application, initiating object requests.
• DNS directs the request regarding latency to the nearest CloudFront edge location.
• At the edge location, CloudFront checks its cache for the requested files. If found, CloudFront promptly returns the cached files to the user, optimizing content delivery.

Q14: How Can User Access to Private Content Be Managed in Amazon Cloudfront, and What Are the Two Methods Available?

Answer: User access to private content in Amazon CloudFront can be controlled through two methods:

• They restrict access to objects in the CloudFront edge cache using signed URLs or cookies.
• Limiting access to objects in the Amazon S3 bucket ensures users can only access content through Amazon CloudFront and not directly from the S3 bucket.

Q15: How Does Geo Restriction or Geo Blocking Work in Amazon Cloudfront, and What Options Are Available for Controlling Access to Content Based on Geographic Locations?

Answer: Geo Restriction in Amazon CloudFront allows you to limit access to your content by configuring an allowlist or blocklist of countries. This control ensures content delivery only to countries where you have distribution rights. 

Activation can be done through the Amazon CloudFront API or Management Console. When a viewer from a restricted country requests content, CloudFront responds with an HTTP 403 (Forbidden) status code. Custom Error Pages can also be configured to tailor the response for viewers in restricted regions.

Conclusion

Efficient AWS SysOps Storage Systems are vital for seamless cloud operations. Remember that expertise in the AWS is a continuous journey. To enhance your skills further, consider the JanBask Training AWS Sysops Training Program.