Farhad Saberi's lightning talk from http://www.meetup.com/SF-Bay-Area-Large-Scale-Production-Engineering/calendar/15464663/

3. Overview and Arhitecture Read only Load Balancing with multiple –proxy-read-only-backend-addresses option

5. No need to restart for configuration or behavioral changes. It all happens in real time.

7. Deny/allow queries based on DB or DB User.

8. Deny/allow based on a regex

9. Construct your own results set and return it to the application without ever actually querying the backend database.

10. LUA embedded

12. Coded in C

13. implements connection pooling

14. Doesn't need to do NS lookups every time

15. Has never “crashed” on me so far!

16. Making the case for mysql-proxy Open source.

18. Small: its whole distribution fits in a floppy disk.

19. Extensible; it is easy to interface with C code.

23. Lua examples Deny all queries to any backend DB: function read_query(packet) if string.byte(packet) == proxy.COM_QUERY then local fields = { } local rows = { } fields = { { name = “ message from DBA ”, type =proxy.MYSQL_TYPE_STRING}, } rows[1] = { “ maintenance ”} proxy.respose = { type = proxy.MYSQLD_PACKET_OK, resultset = { fields = fields, rows = rows } } return proxy.PROXY_SEND_RESULT –means bypass backend, return to client now end end

28. Choose your backend DB based on which IP address, or which mysql user the client has.

29. Modify result set by adding or removing a column from the returned table.

30. Time your queries. Gather statistics.

31. Your limits are that of the Lua language.

33. Start mysql-proxy with admin options:

34. --admin-address=127.0.0.1:10008

35. --admin-username=root

36. – admin-password=password

37. --admin-lua-script=/mysql-proxy/share/admin/admin.lua

38. The admin interface Function read_query(packet) If packet:byte() ~= proxy.COM_QUERY then return_error(“ [admin] we only handle COM_QUERY ”); --user defined end Local rows = { } local fields = { } – no need for a semicolon in Lua if packet:sub(2) == “ls” then – if query is an ls fields = { { name = “ backend_ndx ”, type = proxy.MYSQL_TYPE_LONG }, { name = “ address ” , type = proxy.MYSQL_TYPE_STRING } , { name = “ connected_clients ”, type = proxy.MYSQL_TYPE_LONG}, } for i = 1 , #proxy.global.backends do Local b = proxy.global.backends[i] rows[#rows + 1 ] = { i, b.dst.name, b.connected_clients } end end … Now build proxy.response and return with proxy.PROXY_SEND_RESULT

39. The admin interface Querying the previously Lua coded interface will return: mysql>msyql -u root -ppassword -h 127.0.0.1 -P 10008 mysql> ls; +------------------+--------------------------+-------------------------+ | backend_ndx | address | connected_clients | +------------------+--------------------------+-------------------------+ | 1 | 192.168.1.9:3309 | 23 | +------------------+--------------------------+-------------------------+ | 2 | 192.168.1.10:3309 | 142 | +------------------+--------------------------+-------------------------+

41. A bit complicated. Everything has to be coded by you.

42. You need to know Lua well. (not a bad thing though)