Benchmark the overhead of the luafilter

Knowing the overhead that the luafilter adds would be valuable as it can be used to customize the behavior of MaxScale. Testing just the raw overhead with the example script (in the documentation) should give us a good estimate of what it costs to use the filter.

Config:

[MyLuaFilter]

type=filter

module=luafilter

global_script=/path/to/script.lua

Script:

function createInstance(name)

end

function newSession(user, host)

end

function closeSession()

end

function routeQuery(query)

end

function clientReply(server)

end

function diagnostic()

end