DBLE vs PgDoorman

DBLE is free, open-source middleware for scaling MySQL through sharding. It uses the MySQL protocol and can replace MySQL in many cases without application code changes. Teams can configure hash, modulo, time-based, range-based, or custom sharding, along with global and ER tables. DBLE lists query routing, connection pooling, load balancing, automatic failover, read/write separation, master-slave expansion, and ZooKeeper cluster deployment. SQL support includes SQL 92 and MySQL dialect features such as joins, unions, grouping, ordering, and distinct queries; some features remain on its roadmap. Query optimization addresses global-table joins, sharded tables, ER relations, and subqueries. Distributed transactions use two-phase commit in normal or XA modes, with XA depending on MySQL 5.7 XA transactions, backend availability, and disk reliability. Security controls include password encryption, IP allowlists, and SQL denylists. Explain plans, MySQL-compatible slow logs, and slow-query reports support operations. DBLE is self-hosted on Linux and GPL-2.0 licensed. The open-source plan costs nothing.

PgDoorman is a free, open-source, self-hosted PostgreSQL connection pooler written in Rust. It is described as a drop-in replacement for PgBouncer and Odyssey, and supports PostgreSQL 10 and newer on Linux or macOS. Listed capabilities include connection pooling, load balancing, and automatic failover; query routing is not supported. The pool coordinator enforces per-database connection caps and can reclaim idle capacity from pools with spare connections. Patroni-assisted fallback can direct new connections to another live cluster member during a switchover. Monitoring includes a Prometheus endpoint and an optional local diagnostic console for pool, latency, error, query, log, CPU, and memory information. Authentication includes MD5 or SCRAM passthrough, auth_query, PAM, JWT, Talos JWT, and pg_hba.conf rules. TLS is supported for client and backend connections. It can be built from source, installed from packages, or downloaded as a binary.