Horizontal scaling techniques with PostgreSQL elastic clusters

Scaling databases to meet growing demands is a fundamental requirement for modern applications. While traditional vertical scaling focuses on upgrading a single machine, horizontal scaling offers a more flexible approach by distributing data across multiple nodes. PostgreSQL’s elastic clusters, powered by Azure Database for PostgreSQL Flexible Server and the open-source Citus extension, bring efficient horizontal scaling to the forefront.

In this article, we’ll explore horizontal scaling concepts, compare it with vertical scaling, and discuss its implementation and best practices using PostgreSQL elastic clusters.

Horizontal scaling vs. Vertical scaling

Vertical scaling enhances a database’s performance by increasing the resources of a single server, such as adding more CPU, memory, or storage. While this approach is straightforward, it eventually hits physical and cost limits.

Horizontal scaling, on the other hand, distributes data across multiple servers (nodes) to handle increasing workloads. This method is more cost-effective for large-scale applications and avoids the single point of failure inherent in vertical scaling. PostgreSQL elastic clusters make horizontal scaling seamless by automatically managing sharding, query distribution, and load balancing across nodes.

PostgreSQL elastic clusters: Configuration and features you need to know

PostgreSQL elastic clusters offer a managed horizontal scaling solution. The system uses sharding to split data across multiple nodes, each capable of handling read and write operations. Key features include:

• Unified endpoint: A single connection point simplifies application management.
• Sharding options: Supports both schema-based and row-based sharding for flexible data distribution.
• Scalability: Easily add nodes as your application grows without rewriting code or disrupting workloads.
• Distributed queries: Queries are automatically distributed across nodes, reducing bottlenecks.

To create an elastic cluster, developers can configure settings in the Azure portal, choosing up to 10 nodes during the preview phase. PostgreSQL elastic clusters also include high availability and disaster recovery options, ensuring reliability.

Sharding models in PostgreSQL elastic clusters

• Schema-Based Sharding:

This approach assigns entire schemas to individual shards, making it ideal for applications with multi-tenant architectures. For example, if each customer has a dedicated schema, data for each tenant remains isolated, simplifying scalability. Schema-based sharding requires minimal code changes, making it suitable for lift-and-shift migrations.

• Row-Based Sharding:

Row-based sharding splits tables into smaller chunks based on a distribution key, such as tenant_id or device_id. This model is highly effective for applications requiring dense packing of data across nodes. Proper selection of the distribution key is crucial to ensure data is evenly distributed and avoids hotspots. For example, commands like SELECT create_distributed_table(‘accounts’, ‘account_id’); enable row-based sharding effortlessly.

Performance optimization strategies

Maximizing the performance of horizontally scaled PostgreSQL clusters requires:

• Optimal Sharding: Select distribution keys with high cardinality to avoid data skew and ensure balanced workloads.
• Query Optimization: Include distribution keys in WHERE clauses to minimize cross-node queries.
• Load Balancing: Distribute read and write operations across nodes to prevent bottlenecks.
• Dynamic Rebalancing: Redistribute shards automatically during node addition or scaling events using commands like SELECT citus_rebalance_start();.

Use cases for elastic scaling with PostgreSQL elastic clusters

PostgreSQL elastic clusters offer scalable solutions that meet the diverse demands of various industries. Here are some key use cases:

• eCommerce Platforms

Elastic scaling helps eCommerce platforms manage fluctuating user traffic and transaction volumes. It ensures that platforms can handle peak traffic seamlessly, maintain high availability, and process millions of transactions efficiently, especially during sales events or seasonal spikes.

• AI Applications

AI-driven applications require handling massive datasets for training and inference. PostgreSQL elastic clusters support distributed sharding, allowing AI applications to manage and process vectorized data quickly and efficiently. This ensures smooth scaling for large data volumes and high-performance model training.

• SaaS Solutions

Multi-tenant SaaS platforms benefit from PostgreSQL elastic clusters’ schema-based sharding. This allows each tenant’s data to be stored securely and independently while enabling horizontal scaling to support growing user demands, all without compromising performance.

• Real-Time Analytics

Real-time analytics platforms require fast query execution across large datasets. PostgreSQL elastic clusters enable rapid querying and analysis of distributed data, ensuring timely insights. This is essential for industries like finance and healthcare, where data-driven decisions must be made quickly.

Implementation best practices

• Plan for growth: Start with a smaller cluster and scale out as needed to manage costs efficiently.
• Leverage tutorials: Follow PostgreSQL elastic cluster guides for schema-based or row-based sharding to align with your application architecture.
• Monitor resource usage: Continuously evaluate CPU, storage, and connections to avoid performance bottlenecks.
• Test before production: Validate sharding configurations and query performance in a staging environment.

Conclusion

PostgreSQL elastic clusters offer a robust solution for horizontal scaling, enabling organizations to handle growing workloads with efficiency and flexibility. By automating shard management and distributing data intelligently, elastic clusters simplify the challenges of scaling databases while ensuring high performance. Whether you’re supporting multi-tenant applications, running analytics, or managing real-time dashboards, PostgreSQL elastic clusters can meet your needs with ease.

Discover how AVASOFT can help you implement and optimize PostgreSQL elastic clusters for your business.