I have been working a lot with MySQL proxy lately and trying to figure out how it works is a major PITA. There is virtually no documentation for it and the best way to understand how it actually works is to read the source code.

This is a list of API functions discovered by reading plugin.c in the mysql_proxy SVN source. The list may be incomplete or not entirely accurate.

Bear with me as I try to get better <pre> tag stylization, right now this is the best I can do.

[i] = integer based index

[s] = string based index

[proxy]

proxy.global - data structure shared amongst all lua state machines

proxy.global.config - sub structure (possibly added for esthetical reasons only)

proxy.backends - array of backends (shared)

proxy.connection - mysql connection object

[proxy.backends[i]]

proxy.backends[i].connected_clients - connected clients

proxy.backends[i].address - server Address

proxy.backends[i].state - status {BACKEND_STATE_UNKNOWN, BACKEND_STATE_UP, BACKEND_STATE_DOWN}

proxy.backends[i].type - type {BACKEND_TYPE_UNKNOWN, BACKEND_TYPE_RW, BACKEND_TYPE_RO}

proxy.backends[i].pool - connection pool object

[proxy.backends[i].pool]

proxy.backends[i].pool.max_idle_connections - max connections

proxy.backends[i].pool.min_idle_connections - min connections

proxy.backends[i].pool.users - hash table containing sockets hashed by username

[proxy.backends[i].pool.users[s]]

proxy.backends[i].pool.users[s].cur_idle_connections - number of sockets currently in the pool (meaning they are idle)

[proxy.connection]

proxy.connection.backend_ndx - id of active backend (magic value, setting it can trigger server socket changes, i.e: setting it to 0 returns the socket into the connection pool)

proxy.connection.server - server socket object

proxy.connection.client - client socket object

[proxy.connection.client]

proxy.connection.client.default_db - database

proxy.connection.client.username - user

proxy.connection.client.address - ip address (?)

proxy.connection.client.scrambled_password - password as it was sent from the client

[proxy.connection.server]

proxy.connection.server.default_db - database

proxy.connection.server.username - user

proxy.connection.server.address - ip address (?)

proxy.connection.server.scrambled_password - password as it was sent from the client

proxy.connection.server.mysqld_version - mysql version

proxy.connection.server.thread_id - connection id as set during the server handshake

proxy.connection.server.scramble_buffer - password hash (?)