What are some limitations of Physical Partitions and why is it important to monitor?
Physical partitions in Azure Cosmos DB have certain limitations that can impact the performance and scalability of your database. It is crucial to monitor these limitations to ensure efficient utilization of resources and to address any potential issues. Here are some limitations of physical partitions in Cosmos DB:
- Maximum Storage Size:
- Each physical partition in Cosmos DB has a maximum storage size limit. The current limit is 20 GB per physical partition in most regions. If the data within a partition exceeds this limit, it will not be able to grow further within that partition. Monitoring the storage size of each partition helps you plan for data growth and avoid hitting this limit.
- Maximum Throughput:
- Each physical partition has a maximum throughput capacity known as Request Units per Second (RUs). The total throughput capacity of a container is the sum of the RUs across all physical partitions. Monitoring the throughput consumption and ensuring it stays within the capacity of each physical partition is essential for maintaining optimal performance and avoiding throttling.
- Hot Partitions:
- Hot partitions refer to physical partitions that experience a disproportionate amount of read and write operations compared to others. This can lead to performance degradation and throttling of requests. Monitoring the workload distribution across partitions helps identify hot partitions and take corrective actions such as redistributing data or adjusting partitioning strategies.
- Limited Scalability:
- Cosmos DB partitions data across physical partitions to achieve scalability. However, there is a limit to the number of physical partitions available for a given container. Monitoring the data growth and workload patterns allows you to proactively plan for scaling operations and avoid hitting the scalability limits of physical partitions.
- Data Movement and Migration:
- Data movement or migration may be required when scaling throughput or redistributing data across partitions. Monitoring the data movement process helps ensure its successful completion and minimizes the impact on query performance during migration.
By monitoring these limitations, you can make informed decisions about scaling, data distribution, and partition management in Cosmos DB. Monitoring also enables you to identify potential performance bottlenecks, hot partitions, or storage constraints, allowing you to take proactive measures to optimize performance, improve scalability, and ensure a smooth operation of your application.