Need some help with manual backend switching

[Anton Vorobev]

I've got two backends and I have to switch mysqlproxy from one to another manually.As I understood, now I can do it only by changing backend_ndx inside connect_server(). So, I try to do it via this lua script:


ndx=0
function connect_server( )
local file = io.open("/root/lua/backend_ndx", "r") -- file contains only desired backend index (0 or 1)
ndx = file:read()
proxy.connection["backend_ndx"] = ndx
print (proxy.connection["backend_ndx"])
end

function read_query( packet )
local file = io.open("/root/lua/backend_ndx", "r")
local new_ndx = file:read()

print ("< new ndx: " .. new_ndx .. " >")
if new_ndx ~= ndx then
proxy.response = {
type = proxy.MYSQLD_PACKET_ERR,
errmsg = "Backend has changed"
}

return proxy.PROXY_SEND_RESULT
end

proxy.queries:append(1, packet )
return proxy.PROXY_SEND_QUERY
end



It works fine, but when I stop mysql server on backend and already connected client tries to reconnect, mysqlproxy gets caught in an endless loop trying to connect to backend. Without line `proxy.connection["backend_ndx"] = ndx` it tries to reconnect only once, as I expected. What am I doing wrong? Help, please.