10 Cosmos DB Best Practices

Cosmos DB is a globally distributed, multi-model database service from Microsoft Azure. It is designed to enable developers to quickly and easily build applications that are globally distributed and highly available.

Cosmos DB is a powerful tool, but it can be difficult to use if you don’t know the best practices. In this article, we’ll discuss 10 best practices for using Cosmos DB to ensure that your applications are running optimally. We’ll cover topics such as data modeling, indexing, and performance tuning. By following these best practices, you can ensure that your applications are running smoothly and efficiently.

1. Use the right consistency level

Cosmos DB offers five different consistency levels, each of which has its own trade-offs. The right choice for your application depends on the type of data you’re storing and how often it needs to be accessed. For example, if you need low latency reads and writes, then a strong consistency level is best. On the other hand, if you don’t mind some eventual consistency in exchange for higher availability, then a weaker consistency level might be more appropriate.

By choosing the right consistency level for your application, you can ensure that your data remains consistent while also taking advantage of Cosmos DB’s scalability and performance benefits.

2. Choose the appropriate partition key

Partitioning is a key factor in Cosmos DB’s scalability and performance. When you choose the right partition key, it ensures that data is evenly distributed across all partitions. This helps to ensure that queries are fast and efficient, as well as reducing the cost of storage and throughput.

When selecting a partition key, make sure it meets the following criteria:
– It should be unique for each item in your database
– It should have an even distribution of values
– It should be immutable (i.e., not changeable)
– It should be used frequently in queries

3. Avoid hot partitions

Cosmos DB is a distributed database, meaning that it stores data across multiple nodes. When one node becomes overloaded with requests, this can cause performance issues for the entire system. This is known as a hot partition.

To avoid hot partitions, you should spread your data evenly across all of the nodes in your Cosmos DB cluster. You can do this by using partition keys to ensure that each node has an equal amount of data. Additionally, you should monitor your usage and adjust your partition key if necessary.

4. Keep your documents small

Cosmos DB is a NoSQL database, which means that it stores data in documents. Documents are stored as JSON objects and can contain any number of fields.

However, the larger your documents become, the more expensive they will be to store and query. This is because Cosmos DB charges for storage and throughput based on the size of each document. So if you have large documents with lots of fields, you’ll end up paying more than necessary.

To keep costs down, try to limit the number of fields in each document and make sure that only relevant information is included. Additionally, consider using compression techniques such as gzip or bzip2 to reduce the size of your documents even further.

5. Use stored procedures and triggers to enforce data integrity

Stored procedures and triggers are server-side scripts that can be used to validate data before it is written or updated in the database. This helps ensure that only valid data is stored, which reduces the risk of errors and improves overall data quality.

For example, you could use a stored procedure to check if an email address is valid before writing it to the database. Or you could use a trigger to make sure that all customer records have a unique ID number. By using these features, you can help ensure that your data remains consistent and accurate.

6. Leverage change feed for asynchronous processing

Change feed is a feature of Cosmos DB that allows you to track changes in your data over time. This means that when new documents are added, updated, or deleted from your database, the change feed will capture those events and allow you to process them asynchronously.

This can be incredibly useful for applications that need to react quickly to changes in their data. For example, if you have an application that needs to send out notifications whenever a document is changed, you could use the change feed to detect these changes and trigger the notification system.

By leveraging change feed, you can ensure that your application is always up-to-date with the latest changes in your data, allowing it to respond quickly and accurately to user requests.

7. Use bulk executors to improve throughput

Bulk executors allow you to send multiple requests in a single batch, which reduces the number of round trips between your application and Cosmos DB. This can significantly improve performance by reducing latency and increasing throughput.

Bulk executors also help reduce costs since they enable you to use fewer request units (RUs) per operation. By using bulk executors, you can optimize your RU usage and save money on your Cosmos DB bill.

Finally, bulk executors are easy to implement and require minimal code changes. All you need to do is create a BulkExecutor object with the appropriate parameters and then call its execute method.

8. Monitor performance metrics

Cosmos DB is a distributed database, and as such it’s important to monitor the performance of each node in the cluster. This will help you identify any potential issues before they become serious problems.

You should also be monitoring throughput, latency, storage utilization, and other metrics that are specific to your application. By doing this, you can ensure that your Cosmos DB instance is running optimally and that your applications are performing as expected. Additionally, monitoring these metrics can help you plan for future capacity needs and make sure that your system is always ready to handle increased load.

9. Use Azure Cosmos DB Emulator

The emulator allows you to develop and test your applications locally without having to use the cloud. This is especially useful for development teams who want to quickly iterate on their application without incurring any costs or dealing with latency issues that can arise from using a remote database.

The emulator also provides an easy way to simulate different Cosmos DB configurations, such as throughput levels, indexing policies, and consistency levels. This makes it easier to find the optimal configuration for your application before deploying it to production. Finally, the emulator supports all of the features available in Azure Cosmos DB, so you can be sure that what works in the emulator will work in the cloud.

10. Use Azure Cosmos DB SDKs

Azure Cosmos DB SDKs are designed to make it easier for developers to interact with the database. They provide a set of APIs that allow you to easily create, read, update, and delete data in your Cosmos DB instance. The SDKs also offer features such as automatic retries, connection pooling, and batch operations which can help improve performance and scalability.

Using Azure Cosmos DB SDKs is an important best practice because they simplify development and reduce the amount of code needed to interact with the database. This makes it easier to maintain and debug applications, and helps ensure that your application is optimized for performance.