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MySQL Proxy读写分离脚本

2010年07月12日 IT运维 ⁄ 共 5893字 暂无评论 ⁄ 被围观 7+

注意:第一次client连接时,是不能读写分离的,呵呵,中间使用到连接池的概念,看到你后端server有多个连接时,不要悲伤,不要哭泣,不要怒骂,这是正常的

启动方法:/usr/bin/mysql-proxy -b 10.50.21.130:3306 -r 10.0.0.3:3308 --proxy-lua-script=/home/opensoce/lua-proxy/rw-splitting.lua

脚本文件名: rw-splitting.lua,脚本内容如下:

[php]local commands = require("proxy.commands")
local tokenizer = require("proxy.tokenizer")
local lb = require("proxy.balance")

if not proxy.global.config.rwsplit then
proxy.global.config.rwsplit = {
max_idle_connections = 30,
is_debug = false
}
end

--local is_in_transaction = false

function connect_server()
local is_debug = proxy.global.config.rwsplit.is_debug
local rw_ndx = 1
local min_cur_idle_connections=1000000

-- init all backends
for i = 1, #proxy.global.backends do
local s = proxy.global.backends[i]
local pool = s.pool -- we don't have a username yet, try to find a connections which is idling
local cur_idle = pool.users[""].cur_idle_connections
if min_cur_idle_connections > cur_idle
then
min_cur_idle_connections=cur_idle
rw_ndx=i
end
end

proxy.connection.backend_ndx = rw_ndx

if is_debug then
print()
print("[connect_server] " .. proxy.connection.client.src.name)
print("[server] " .. proxy.global.backends[proxy.connection.backend_ndx].dst.name)
end

end

function read_auth_result( auth )
local is_debug = proxy.global.config.rwsplit.is_debug
if is_debug then
print("[read_auth_result] " .. proxy.connection.client.src.name)
end
if auth.packet:byte() == proxy.MYSQLD_PACKET_OK then
-- auth was fine, disconnect from the server
proxy.connection.backend_ndx = 0
elseif auth.packet:byte() == proxy.MYSQLD_PACKET_EOF then
-- we received either a
--
-- * MYSQLD_PACKET_ERR and the auth failed or
-- * MYSQLD_PACKET_EOF which means a OLD PASSWORD (4.0) was sent
print("(read_auth_result) ... not ok yet");
elseif auth.packet:byte() == proxy.MYSQLD_PACKET_ERR then
-- auth failed
end
end

function read_query( packet )
local is_debug = proxy.global.config.rwsplit.is_debug
local cmd = commands.parse(packet)
local c = proxy.connection.client

local tokens

-- looks like we have to forward this statement to a backend
if is_debug then
print("[read_query] " .. proxy.connection.client.src.name)
print(" current backend = " .. proxy.connection.backend_ndx)
print(" client default db = " .. c.default_db)
print(" client username = " .. c.username)
if cmd.type == proxy.COM_QUERY then
print(" query = " .. cmd.query)
end
end

if cmd.type == proxy.COM_QUIT then
-- don't send COM_QUIT to the backend. We manage the connection
-- in all aspects.
proxy.response = {
type = proxy.MYSQLD_PACKET_OK,
}

if is_debug then
print(" (QUIT) current backend = " .. proxy.connection.backend_ndx)
end

return proxy.PROXY_SEND_RESULT
end

proxy.queries:append(1, packet, { resultset_is_needed = true })

if not is_in_transaction and
cmd.type == proxy.COM_QUERY then
tokens = tokens or assert(tokenizer.tokenize(cmd.query))

local stmt = tokenizer.first_stmt_token(tokens)

if stmt.token_name == "TK_SQL_SELECT" then

local is_insert_id = false

for i = 1, #tokens do
local token = tokens[i]
local utext = token.text:upper()
if token.token_name == "TK_LITERAL"
then
if utext == "@@LAST_INSERT_ID" then
is_insert_id = true
end
elseif token.token_name == "TK_FUNCTION"
then
if utext == "LAST_INSERT_ID" then
is_insert_id = true
end
end

end

if not is_insert_id
then local backend_ndx = lb.idle_ro()

if backend_ndx > 0 then
proxy.connection.backend_ndx = backend_ndx
end
else
print(" found a SELECT LAST_INSERT_ID(), staying on the same backend")
end
end
end

if proxy.connection.backend_ndx == 0 then
-- we don't have a backend right now
--
-- let's pick a master as a good default
--
proxy.connection.backend_ndx = lb.idle_failsafe_rw()
end

-- by now we should have a backend
--
-- in case the master is down, we have to close the client connections
-- otherwise we can go on
if proxy.connection.backend_ndx == 0 then
return proxy.PROXY_SEND_QUERY
end

local s = proxy.connection.server

if cmd.type ~= proxy.COM_INIT_DB and
c.default_db and c.default_db ~= s.default_db then
print(" server default db: " .. s.default_db)
print(" client default db: " .. c.default_db)
print(" syncronizing")
proxy.queries:prepend(2, string.char(proxy.COM_INIT_DB) .. c.default_db, { resultset_is_needed = true })
end

-- send to master
if is_debug then
if proxy.connection.backend_ndx > 0 then
local b = proxy.global.backends[proxy.connection.backend_ndx]
print(" sending to backend : " .. b.dst.name);
print(" is_read_only[slave server] : " .. tostring(b.type == proxy.BACKEND_TYPE_RO));
print(" server default db: " .. s.default_db)
print(" server username : " .. s.username)
end
print(" in_trans : " .. tostring(is_in_transaction))
print(" COM_QUERY : " .. tostring(cmd.type == proxy.COM_QUERY))
end

return proxy.PROXY_SEND_QUERY
end

function read_query_result( inj )
local is_debug = proxy.global.config.rwsplit.is_debug
local res = assert(inj.resultset)
local flags = res.flags

if inj.id ~= 1 then
-- ignore the result of the USE <default_db>
-- the DB might not exist on the backend, what do do ?
--
if inj.id == 2 then
-- the injected INIT_DB failed as the slave doesn't have this DB
-- or doesn't have permissions to read from it
if res.query_status == proxy.MYSQLD_PACKET_ERR then
proxy.queries:reset()

proxy.response = {
type = proxy.MYSQLD_PACKET_ERR,
errmsg = "can't change DB ".. proxy.connection.client.default_db ..
" to on slave " .. proxy.global.backends[proxy.connection.backend_ndx].dst.name
}

return proxy.PROXY_SEND_RESULT
end
end
return proxy.PROXY_IGNORE_RESULT
end

is_in_transaction = flags.in_trans
local have_last_insert_id = (res.insert_id and (res.insert_id > 0))

if not is_in_transaction and
not have_last_insert_id then
-- release the backend
proxy.connection.backend_ndx = 0
elseif is_debug then
print("(read_query_result) staying on the same backend")
print(" in_trans : " .. tostring(is_in_transaction))
print(" have_insert_id : " .. tostring(have_last_insert_id))
end
end

function disconnect_client()
local is_debug = proxy.global.config.rwsplit.is_debug
if is_debug then
print("[disconnect_client] " .. proxy.connection.client.src.name)
end

-- make sure we are disconnection from the connection
-- to move the connection into the pool
if proxy.connection.backend_ndx == 0
then
for i = 1, #proxy.global.backends do
local s = proxy.global.backends[i]
local pool = s.pool
local cur_idle = pool.users[""].cur_idle_connections
pool.max_idle_connections = proxy.global.config.rwsplit.max_idle_connections
if is_debug then
print ("cur_idle="..cur_idle )
print ("pool.max_idle_connections = "..pool.max_idle_connections)
end
if s.state ~= proxy.BACKEND_STATE_DOWN and
cur_idle > pool.max_idle_connections then
-- try to disconnect a backend
proxy.connection.backend_ndx = i
return
end
end
end
end[/php]

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