PGCat

PgCat is a next-generation PostgreSQL pooler and proxy designed to enhance the performance, reliability, and scalability of PostgreSQL databases. It functions similarly to PgBouncer but introduces advanced capabilities like sharding, intelligent load balancing for read queries, and automatic failover. This tool is ideal for organizations and developers managing high-traffic PostgreSQL environments that require robust connection pooling, efficient resource utilization, and continuous availability. By leveraging a multi-threaded runtime built with Tokio, PgCat efficiently utilizes multicore machines, handling a large number of connections and queries per second. It provides critical features for production environments, including transaction and session pooling, secure client/server authentication with SSL/TLS, and live configuration reloading. Its ability to automatically reroute queries around broken replicas and balance read queries across replicas and the primary server ensures high availability and optimal performance, even under heavy loads or during failures. PgCat is particularly beneficial for large-scale applications that need to distribute data across multiple PostgreSQL instances (sharding) or mirror traffic for testing and analysis. While some sharding and mirroring features are still experimental, the core pooling, load balancing, and failover functionalities are stable and proven in production environments, serving hundreds of thousands of queries per second for companies like Instacart and PostgresML.