DBLE vs ProxySQL

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.

ProxySQL is a self-hosted Linux database proxy for MySQL, PostgreSQL and related systems. It scales infrastructure without changes to the application stack or database engine, multiplexing more than 100,000 client connections through a few hundred backend connections. Protocol-aware, regex-based routing can send queries to primary servers, replicas or shards, and can route by user, schema or table. The proxy can cache results without application changes, monitor backend health and reroute traffic during failures. Query mirroring duplicates live traffic for analysis and performance testing, while percentage-based balancing supports gradual shifts. A database firewall is intended to protect against SQL injection and runaway queries. Deployment options include Linux packages, Docker and Kubernetes. ProxySQL is GPLv3-licensed open source, released in 2013. The Community plan is free and includes core features, supported platforms and community channels.