Selecting the appropriate storage service

When considering storage solutions on AWS, how would you differentiate between the use cases for Amazon S3 and Amazon Elastic Block Store (EBS)?

Amazon S3 is object storage built to store and retrieve any amount of data from anywhere, well-suited for storing large amounts of static data, like web content, backups, and media files. It’s ideal for data that is accessed infrequently but requires high durability and availability. Amazon EBS, on the other hand, provides block-level storage volumes for use with EC2 instances. It’s designed for data requiring frequent and fast access, such as the data needed by a database or a file system.

Can you explain how Amazon S3 data consistency models affect the selection of storage for a distributed application?

Amazon S3 offers strong read-after-write consistency for PUTS of new objects and eventual consistency for overwrite PUTS and DELETES, meaning that once you upload a file, you can read it immediately, but if you modify or delete a file, the change might not be visible immediately to all users. This affects distributed applications in that you must design them to handle eventual consistency where necessary. Applications requiring strong consistency for all operations might need to consider alternative storage solutions or add logic to manage consistency.

Describe a scenario where using Amazon S3 Intelligent-Tiering would be beneficial.

S3 Intelligent-Tiering is beneficial for data with unknown or changing access patterns. For instance, if you’re storing a mixture of archival data and data that might be accessed at unpredictable intervals, Intelligent-Tiering can help save costs by automatically moving data to the most cost-effective access tier without performance impact or operational overhead.

How would you ensure high availability and durability for critical data stored on AWS?

To ensure high availability and durability, you would typically store data redundantly across multiple Availability Zones within an AWS Region using services like Amazon S3, which offers 11 nines of durability. Optionally, you can also replicate the data across multiple AWS regions using features like cross-region replication to protect against regional failures.

When would you recommend using Amazon Glacier over Amazon S3 for storage?

Amazon S3 Glacier is recommended for long-term archival storage where data retrieval times of several minutes to hours are acceptable. It’s significantly cheaper for storing data that is rarely accessed, such as regulatory archives and digital preservation, compared to the standard S3 tiers that are designed for more frequent access.

What factors do you consider when selecting between file storage, block storage, and object storage for a given application?

Factors to consider include the access pattern (random or sequential), performance requirements, scalability needs, data structure (file-based, block, or object), the type of workload (database, file sharing, media storage), data retrieval times, and cost-effectiveness.

In which scenario would you consider using AWS Storage Gateway, and why?

AWS Storage Gateway is a hybrid storage service that enables on-premises applications to use AWS cloud storage. You would consider it when you need to integrate on-premises IT environments with cloud storage for backup and archiving, disaster recovery, or data processing, allowing you to maintain existing workflows while leveraging the scalability and cost benefits of the cloud.

How does AWS DataSync assist in migrating large datasets to the cloud, and how do you know when to use it?

AWS DataSync automates and accelerates moving large amounts of data into and out of AWS storage services over the internet or AWS Direct Connect. It’s particularly useful for transferring large datasets, like data lakes or media libraries, and when migrating active data sets to AWS. Use DataSync when you require faster transfer times than traditional methods can provide, need to schedule regular transfers, or must minimize operational overhead.

What are the best practices for ensuring the security of data at rest in AWS S3?

Best practices include enabling S3 default encryption to encrypt objects server-side, using AWS Key Management Service (AWS KMS) for managing encryption keys, implementing bucket policies to control access to the data, enabling versioning to protect against accidental deletions, and using access logs to monitor requests to the buckets.

How would you approach the decision to use Provisioned IOPS with Amazon EBS, and what are the factors that influence this choice?

Provisioned IOPS are chosen when you have workloads with demanding and predictable performance needs, like high-performance database applications. Factors influencing this choice include the required IOPS for your application, the throughput required, and whether the workload experiences peak times with higher performance demands.

Discuss the ideal use cases for using Amazon FSx in comparison to other AWS storage services.

Amazon FSx provides fully managed third-party file systems. FSx for Windows is ideal for Windows-based applications that require Windows file system features, while FSx for Lustre is designed for compute-intensive workloads, like high-performance computing, machine learning, and media processing, providing high-speed and concurrent access to large datasets. Choose FSx when compatibility with specific file system features and native performance is required.

What measures can you take to control costs when using Amazon EBS?

To control costs with Amazon EBS, monitor and delete unused volumes, choose the correct volume type (General Purpose SSD, Provisioned IOPS SSD, Throughput Optimized HDD, Cold HDD) for your workload, leverage EBS snapshots for backups but manage snapshot lifecycle, and consider using reserved instances for predictable workloads that have long-term steady state usage.