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Dynamodb and DocumentDB are two popular NoSQL databases that serve different purposes and have distinct features.
Dynamodb is a fast, fully managed NoSQL database service offered by Amazon Web Services (AWS).
It's designed for applications that require high performance, low latency, and high availability, making it a great choice for real-time web applications, gaming, and mobile applications.
DocumentDB, on the other hand, is a document-oriented database that allows for flexible schema design and high scalability.
It's ideal for applications that require frequent schema changes and high data throughput, such as social media platforms and e-commerce websites.
Additional reading: Amazon Aurora vs Dynamodb
Database Features
DocumentDB is designed to be compatible with MongoDB, making it easier for developers to migrate their existing MongoDB applications to AWS.
DynamoDB simplifies data storage and retrieval with its key-value pair model, performing exceptionally well in scenarios requiring high-speed, low-latency performance.
DocumentDB provides a more flexible data model that supports complex nested structures, useful for applications where the data schema evolves over time or where intricate document structures are required.
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DynamoDB automatically partitions and distributes data to handle changing workloads, ensuring consistent performance even during traffic spikes. DocumentDB scales horizontally by adding read replicas to handle read-heavy workloads.
DynamoDB provides low-latency, predictable read and write performance, ideal for high-performance applications. DocumentDB's performance is similar to that of MongoDB, making it an excellent choice for applications looking to migrate seamlessly from MongoDB.
DynamoDB uses a pay-as-you-go pricing model, in which you only pay for the read and write capacity that you use. DocumentDB adds the option of reserved instances, allowing you to commit to a one- or three-year term for predictable pricing.
Here are the key features of DocumentDB:
- MongoDB Compatibility: Allows the use of existing MongoDB drivers and tools.
- Scalability and Performance: Automatically scales storage and compute resources.
- Durability and Availability: Continuous backups and multi-AZ deployments ensure data durability and high availability.
- Security: Offers encryption at rest and in-transit, along with AWS’s standard security features.
Performance
Performance is a critical aspect of any database, and both DynamoDB and DocumentDB excel in this area. DynamoDB uses an array of SSDs spread across multiple partitions to store data in a table, offering single-digit millisecond latency to every request.
This means that DynamoDB can handle a massive 20 million requests per second without any performance loss, making it an ideal choice for large-scale applications. Developers can also integrate DynamoDB Accelerator (DAX) to improve read performance and achieve microsecond latency, resulting in a 10x read performance improvement.
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DynamoDB's scalable architecture allows it to automatically replicate data across AWS regions, ensuring rapid read and write performance for globally distributed applications. This feature is particularly useful for applications that require low-latency access to data.
In contrast, DocumentDB uses a scalable in-memory optimized architecture that allows it to evaluate queries faster for larger datasets. This results in faster query performance and a higher read throughput to process millions of requests per second without throttling.
Here are some key performance metrics for DynamoDB:
- Tables replicate data across AWS regions automatically for rapid read and write performance
- Scales tables up and down automatically to maintain performance and adjust for capacity
- DynamoDB performance tests reveal a monthly uptime of 99.999% SLA per AWS region
- Fully managed in-memory caching dramatically reduces read time
- Backups affect neither application performance nor availability
- Application performance monitoring scales up and down automatically with application traffic
DocumentDB also uses up to 15 read replicas to provide a higher read throughput and process millions of requests per second without throttling.
Availability & Durability
DynamoDB is highly durable, spreading incoming traffic across multiple servers to ensure each server performs optimally and can manage the load without throttling.
This approach prevents servers from unexpectedly going down due to high loads, ensuring high availability.
DynamoDB replicates data across multiple availability zones, allowing users to access data even if one server fails.
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Each availability zone is a separate physical location, providing an added layer of protection against data loss.
DocumentDB, on the other hand, allows developers to create up to 15 read replicas across multiple availability zones.
This improves availability by automating failover to a read replica whenever an instance fails.
Ultimately, this helps users access data even when an instance fails, minimizing downtime and ensuring business continuity.
Curious to learn more? Check out: Data Lake vs Databricks
Security
Security is a top concern for any database, and both DynamoDB and DocumentDB offer robust security features.
DynamoDB supports encryption at rest using three KMS key types: AWS Owned Key, AWS Managed Key, and Customer Managed Key.
Developers can configure encryption using these key types, but note that methods 2 and 3 are subject to KMS charges.
DynamoDB also allows developers to declare granular access to DynamoDB resources using the IAM service, enabling fine-grained access control.
DocumentDB, on the other hand, runs inside a VPC, giving developers the flexibility to define firewall settings that control network access to the cluster.
DocumentDB supports encryption at rest with 256-bit AES-256 using symmetric encryption keys stored at AWS KMS, but this is not enabled by default.
Only clusters created using the AWS Console have encryption at rest enabled by default.
DocumentDB also supports encryption in transit using TLS to ensure secure connections to the cluster.
Here are the key differences in encryption options between DynamoDB and DocumentDB:
- DynamoDB offers three KMS key types for encryption at rest.
- DocumentDB supports encryption at rest with 256-bit AES-256, but only for clusters created using the AWS Console.
- DocumentDB supports encryption in transit using TLS.
Scalability and Pricing
DynamoDB is highly scalable and can serve over 20 million requests per second without performance loss. It uses two capacity modes: Provisioned and On-Demand.
DocumentDB is also highly scalable, allowing developers to scale the cluster's storage and compute to help scale the database as data and traffic grow. It provides four types of scaling: Storage Scaling, Instance Scaling, Read Scaling, and Write Scaling.
DynamoDB charges based on the capacity model, whereas DocumentDB has a strict model of only paying for what you use, requiring no upfront payments. DocumentDB's pricing model comprises four dimensions: On-demand instances, Database I/O, Database storage, and Database backup storage.
Here's a comparison of the two services' pricing models:
Scalability
Scalability is a crucial aspect of any database service, and both DynamoDB and DocumentDB offer impressive scalability features.
DynamoDB can serve over 20 million requests per second without performance loss, thanks to its two capacity modes: Provisioned and On-Demand.
The Provisioned mode allows you to specify the required minimum and maximum WCU and RCU units when creating the table, which is suitable for applications with predictable traffic flow.
DynamoDB's On-Demand mode, on the other hand, scales the capacity units up and down based on the application workload and traffic, making it ideal for applications with unpredictable traffic flow.
DocumentDB also offers high scalability, allowing developers to scale the cluster's storage and compute to meet growing data and traffic demands.
DocumentDB provides four types of scaling: Storage Scaling, Instance Scaling, Read Scaling, and Write Scaling.
Storage Scaling happens automatically as the data grows in size, scaling up to 64 TiB.
Instance Scaling allows developers to manually update the cluster's instance class to improve performance.
Read Scaling increases the number of replicas in the cluster to improve read performance.
Write Scaling updates the size of the cluster's primary instance to improve write performance across multiple AZs.
Here's a comparison of the two services' scaling options:
Pricing
Pricing is a crucial aspect to consider when choosing between DynamoDB and DocumentDB. Both services offer a pay-per-use pricing model, which means you only pay for the resources you consume.
DynamoDB charges for reading, writing, and storing data in your table, as well as additional services like streams. You get billed for the WCU and RCU you consume, plus any used backup storage and other DynamoDB services.
DocumentDB, on the other hand, has a strict pay-per-use model with no upfront payments required. Its pricing model comprises four dimensions: on-demand instances, database I/O, database storage, and database backup storage.
Here's a comparison of the pricing models of DynamoDB and DocumentDB in a table:
Both services offer a free tier for limited usage, as well as committed use discounts. DynamoDB has free data transfer within the same region, while DocumentDB charges for all data transfers.
Backup and Recovery
Backup and recovery are crucial for any database. DynamoDB provides two backup mechanisms: point-in-time recovery and on-demand backups. Point-in-time recovery helps DynamoDB maintain continuous backups of table data for the last 35 days.
These backups allow developers to seamlessly restore data within 35 days in case of accidental deletes/updates. The feature is disabled by default. On-demand backups, on the other hand, allow developers to create full table backups with no performance overhead.
DocumentDB offers two types of backups: S3 Backups and AWS Backup. S3 Backups automatically create backups for data during the past 35 days on Amazon S3. AWS Backup allows developers to create snapshots of their table data on AWS Backup and perform restores directly from AWS Backup.
Here's a comparison of the backup mechanisms offered by DynamoDB and DocumentDB:
DocumentDB provides continuous backups to Amazon S3 and allows point-in-time recovery, ensuring that your data is safe and recoverable in the event of a disaster.
Setup and Configuration
To set up a DocumentDB cluster, you'll need to have an AWS account. Ensure you have an AWS account before proceeding with the setup process.
You'll need to create a DocumentDB instance in your cluster, which requires having the AWS CLI installed and configured on your machine, as well as having MongoDB shell (mongosh) for connecting to your DocumentDB cluster.
Here are the steps to create a DB Subnet Group and connect to your DocumentDB cluster:
- Create a DB Subnet Group.
- Once the cluster is available, create a DocumentDB instance in that cluster.
You can also set up a Virtual Private Cloud (VPC) for your DocumentDB cluster for secure networking.
Setting Up Amazon
To set up Amazon DocumentDB, you need to have an AWS account. You can't create a cluster without it, so make sure you've got one set up.
First, navigate to the AWS Management Console. From there, you'll find the option to create a DocumentDB cluster.
To create a cluster, click on 'Create cluster' and follow the steps to specify cluster details, including instance type and number of instances. You'll need to choose the right settings for your project.
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Setting up a Virtual Private Cloud (VPC) for your DocumentDB cluster is a good idea for secure networking. This will help keep your data safe.
You'll also need to define security groups to control access to the cluster. These groups determine who can access your cluster and what actions they can perform.
Comparison and Choosing
When considering DynamoDB and DocumentDB, it's essential to think about your specific use case. If high-performance scenarios are crucial, DynamoDB might be the way to go, thanks to its low-latency access.
DynamoDB's simplicity also makes it a great choice for projects with simple key-value or document storage requirements. This simplicity can simplify development and get your project up and running faster.
Here's a brief comparison of the two services to help you make an informed decision:
Ultimately, the choice between DynamoDB and DocumentDB depends on your project's specific needs. If MongoDB compatibility is critical, or your project requires a flexible schema with complex data structures, DocumentDB might be the better choice.
Comparison Between AWS
When choosing between AWS DynamoDB and DocumentDB, it's essential to consider their primary use cases. DynamoDB is a NoSQL database for key-value and document data, while DocumentDB is a document-oriented database compatible with MongoDB.
DynamoDB's flexible schema allows attributes to vary per item, making it suitable for handling diverse data structures. This flexibility is also present in DocumentDB, where documents within a collection can have varying attributes.
Automatic scaling based on demand is a key feature of DynamoDB, ensuring that your database can handle sudden spikes in traffic. In contrast, DocumentDB requires manual scaling with read and write capacity units.
Both DynamoDB and DocumentDB support ACID-compliant transactions, ensuring that your database operations are reliable and consistent. They also offer eventual consistency and strongly consistent reads, providing flexibility in data consistency models.
Here's a quick comparison of the two services:
Both services offer high performance and efficient query optimization, making them suitable for demanding applications. However, DynamoDB's highly scalable architecture makes it a better choice for applications with unpredictable traffic patterns.
Choosing a Database
Choosing a database can be a daunting task, especially with the numerous options available. Relational databases store data in tables with columns and rows, but for high-performance scenarios, a NoSQL database like DynamoDB might be a better fit.
DynamoDB is ideal for applications that require low-latency access, making it suitable for real-time data processing. Its flexible schema aligns with the needs of many projects, allowing for easy data modeling.
On the other hand, DocumentDB is a better choice when MongoDB compatibility is critical or when complex data structures are required. Its document-oriented database design makes it easy to store and retrieve data in a hierarchical format.
Here's a quick comparison of DynamoDB and DocumentDB:
In addition to these two options, there are other types of databases to consider, such as key-value databases, in-memory databases, and graph databases. Each has its own strengths and weaknesses, and the choice ultimately depends on your specific use case and development preferences.
Best Practices and Optimization
Proper indexing is crucial for query performance. This is especially true when working with large datasets, as it can significantly speed up query times.
Amazon CloudWatch is a powerful tool for monitoring database performance. It allows you to set up alarms for key metrics, so you can quickly identify and address any issues that may arise.
Analyzing your queries for performance using the built-in query engine is a great way to optimize your database. This can help you identify slow-running queries and make adjustments to improve overall performance.
Monitoring database performance is essential to ensure it's running smoothly. By setting up alarms for key metrics, you can catch any potential issues before they become major problems.
Recommended read: Documentdb Cloudwatch Metrics
Data Modeling
Data Modeling is a crucial aspect of NoSQL databases, and it's not just about migrating from SQL to NoSQL. Our experts offer a 3-hour masterclass on data modeling for NoSQL databases that covers techniques and best practices to avoid mistakes.
Amazon S3 is a cloud storage service that's scalable and high-speed, making it perfect for archiving and backing up data and applications on AWS. It's an object store that holds large amounts of binary unstructured data grouped into buckets, each associated with a region.
Use Cases
DynamoDB is perfect for building scalable and fast applications, handling millions of concurrent requests per second with single-digit millisecond latency.
DynamoDB's speed and scalability make it ideal for near-real-time applications, such as sensory applications that require quick response times.
E-commerce platforms that demand high throughput and low latency also benefit from DynamoDB's capabilities.
Gaming applications that need to handle large volumes of player data in real-time can rely on DynamoDB's performance.
IoT applications that collect and process data from numerous devices can also take advantage of DynamoDB's scalability.
Here are some specific use cases for DynamoDB:
On the other hand, DocumentDB is a good fit for applications with an ever-changing schema, such as building a user profile.
DocumentDB is also suitable for managing big real-time data, content management, and applications that require complex querying capabilities.
Migrating existing MongoDB workloads to a managed service is another use case for DocumentDB.
Frequently Asked Questions
Is DynamoDB a document database?
Yes, DynamoDB supports a document data model, allowing developers to store and manage semi-structured data in a flexible and scalable way. This makes it suitable for building modern applications that require flexible data storage.
Is DocumentDB the same as MongoDB?
No, Amazon DocumentDB is not the same as MongoDB, but it emulates the MongoDB API to provide a similar experience. While it's not a direct copy, DocumentDB offers a compatible alternative for MongoDB users.
Is DynamoDB a datastore?
Yes, DynamoDB is a type of datastore, specifically a key-value store with a schemaless, non-relational data model. It's designed for large-scale, high-performance data storage and retrieval.
Sources
- https://dynobase.dev/dynamodb-vs-documentdb/
- https://medium.com/@christopheradamson253/getting-started-with-amazon-documentdb-f9181a43aad5
- https://www.jeffersonfrank.com/insights/choosing-an-aws-database/
- https://www.scylladb.com/learn/dynamodb/introduction-to-dynamodb/comparison/
- https://k21academy.com/amazon-web-services/aws-solutions-architect/aws-dynamodb-vs-document/
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