postgresml/pgcat
Pgcat
Pgcat 是一个 PostgreSQL 中间件解决方案，提供连接池、分片、负载均衡和故障转移管理。它作为一个代理，通过管理数据库会话并将查询分发到多个实例来优化资源使用和可扩展性。
该系统通过流量镜像脱颖而出，它将实时生产查询复制到测试数据库以进行验证。它还实现了分片代理，根据分片键将数据和查询分发到多个数据库实例。
该项目通过自动故障转移和服务器健康监控涵盖了高可用性。它包括用于分离读写操作的流量路由、用于加密通信的传输层安全 (TLS)，以及用于系统管理和性能指标导出的虚拟管理数据库。
该服务打包为 Docker 容器，以确保在不同环境中的一致部署。
Features
- PostgreSQL Pool Managers - Manages a pool of database connections specifically tailored for the PostgreSQL wire protocol to optimize resource usage.
- Database Connection Pooling - Manages a pool of reusable backend sessions to reduce the overhead of establishing new database connections.
- SQL Comment Based Routing - Routes queries to specific data partitions using sharding keys extracted from SQL comments or hashing functions.
- Query Routing - Directs queries to specific data partitions using automatic key detection, SQL comments, or custom syntax.
- Horizontal Database Scaling - Distributes data across multiple database instances to scale storage and throughput through horizontal expansion.
- PostgreSQL Database Sharding - Splits data across multiple PostgreSQL servers to scale storage and processing by routing queries via sharding keys.
- PostgreSQL Load Balancers - Provides a protocol-aware proxy to distribute read queries across multiple PostgreSQL backend instances.
- Traffic Routing - Analyzes incoming SQL to automatically direct read-only requests to replicas and write operations to the primary server.
- Replica Load Balancers - Distributes incoming queries across a cluster of available replicas to prevent single-instance bottlenecks.
- Read Load Balancers - Distributes read requests across multiple replicas using random or least-connection algorithms.
- Sharding Proxies - Acts as a routing layer that distributes queries across multiple database instances based on sharding keys.
- Database Failover Routers - Redirects traffic to a healthy standby instance when a primary node becomes unavailable to maintain uptime.
- Database High Availability - Coordinates PostgreSQL nodes to ensure continuous service availability through automated failover and health monitoring.
- Database Failover Management - Monitors backend server health and automatically reroutes traffic to standby instances during primary node failure.
- Health-Based Traffic Rerouting - Monitors backend server availability via periodic probes and automatically reroutes traffic away from unresponsive nodes.
- Upstream Health Monitoring - Performs periodic health checks on backend servers and temporarily blocks unresponsive nodes to ensure stability.
- Database Query Mirroring - Duplicates incoming production queries to test databases to validate new versions or warm up caches.
- Database Connection Encryption - Encrypts communication between clients, the proxy, and database servers using TLS certificates.
- Database Authentication - Validates client identities using secure hashing or external query passthrough to manage database access.
- Transport Layer Security - Secures data in transit between clients and backend servers using certificates and private keys.
- Administrative Command Engines - Executes system management tasks and inspects pool status through a dedicated administrative interface.
- Virtual Administrative Databases - Provides a dedicated virtual administrative database for executing system commands and inspecting pool health.
