MySQLX Plugin Branch Wrap-Up

Date: 2026-04-07 Branch: mysqlx-plugin-impl Worktree: /data/rene/proxysql/.worktrees/mysqlx-plugin-impl

All 9 Tasks Complete

Task	Description	Commit	Tests
1	Generic plugin ABI and loader	7e1a12b8f	plugin_manager_unit-t
2	Plugin configuration and core lifecycle	804771271	plugin_config_unit-t
3	Plugin-owned admin table/command registration	cd15afdd1	plugin_registry_unit-t
4	mysqlx plugin scaffold and build integration	19d48bdc1	test_mysqlx_plugin_load-t (6/6)
5	Config store, runtime tables, dual-mode identity	0b11bce37	mysqlx_config_store_unit-t (16/16), test_mysqlx_admin_tables-t (20/20)
6	Listener sockets and worker threads	5b5bbfbca	test_mysqlx_listener_smoke-t (8/8)
7	Frontend X handshake, auth, account enforcement	05ca510f2	mysqlx_protocol_unit-t (10/10)
8	Backend X sessions and hostgroup-based routing	e087fdda4	mysqlx_route_store_unit-t (8/8)
9	Stats, topology invalidation hooks	c2e90d369	mysqlx_stats_unit-t (7/7)

Plugin Module Map

File	Responsibility
mysqlx_plugin.h/cpp	Plugin descriptor, context, lifecycle hooks
mysqlx_admin_schema.h/cpp	DDL registration, LOAD TO RUNTIME commands, stats table schema
mysqlx_config_store.h/cpp	Runtime caches, dual-mode identity merge, round_robin routing
mysqlx_worker.h/cpp	Listener sockets, accept loop, worker threads
mysqlx_protocol.h/cpp	X frame encode/decode, MYSQL41 scramble auth, protobuf helpers
mysqlx_frontend_session.h/cpp	Client handshake state machine (CapabilitiesGet/Set, Auth)
mysqlx_backend_session.h/cpp	Backend X connect, MYSQL41 auth, bidirectional byte relay
mysqlx_stats.h/cpp	Atomic route counters, SQLite stats flush
proto/*.pb.h/cc	Compiled X Protocol protobuf messages

Config/Runtime Tables

• mysqlx_users / runtime_mysqlx_users — X-specific overrides for dual-mode accounts
• mysqlx_routes / runtime_mysqlx_routes — route definitions with bind/hostgroup
• mysqlx_backend_endpoints / runtime_mysqlx_backend_endpoints — X port mapping
• stats_mysqlx_routes — per-route connection and byte counters
• stats_mysqlx_processlist — (schema registered, flush not yet wired)

Admin Commands

• LOAD MYSQLX USERS TO RUNTIME (aliases: TO RUN, FROM MEMORY, FROM MEM)
• SAVE MYSQLX USERS TO MEMORY (aliases: TO MEM, FROM RUNTIME, FROM RUN)
• LOAD MYSQLX ROUTES TO RUNTIME (aliases: same pattern)
• SAVE MYSQLX ROUTES TO MEMORY (aliases: same pattern)
• LOAD MYSQLX BACKEND ENDPOINTS TO RUNTIME (aliases: same pattern)
• SAVE MYSQLX BACKEND ENDPOINTS TO MEMORY (aliases: same pattern)

Auth Methods Supported

• MYSQL41 (challenge-response SHA1)
• PLAIN (plaintext, should require TLS in production)

Routing Strategies

• first_available — first ONLINE server in hostgroup
• round_robin — rotate across ONLINE servers
• round_robin_with_fallback — round_robin, then fallback_hostgroup

Phase 2 Seams

• Topology generation counter captured at session bind time
• bump_topology_generation() available for future GR notification observer
• Policy profile field present on resolved identity but not enforced

Known Limitations (Phase 1)

• One frontend session = one backend session (no pooling)
• pass_through backend auth mode explicitly rejected
• Stats processlist table registered but not flushed during relay
• TLS negotiation acknowledged but not implemented in CapabilitiesSet
• No end-to-end integration test with a live MySQL X backend (requires Docker infrastructure)