why ngx.req.set_header("connection", "Keep-Alive") does not work?

liupengwyy · 2017-01-18T23:14:16+00:00

Hi all, I've came across challenging situation when using NGINX. I have a nginx body filter when returning response to calling client which mod...

why ngx.req.set_header("connection", "Keep-Alive") does not work?

liupengwyy

Hi,

In the location rewrite_by_lua_file script file, I check the "connection" header and also add one if it does not exist.

    local h = ngx.req.get_headers()
    for k, v in pairs(h) do
        ngx.log(ngx.ERR, "header key "..k.." header value "..v)
    end
    local connheader = ngx.req.get_headers()["connection"]

    if (connheader == nil) then
         ngx.log(ngx.ERR,"src webservice connection header is null")
         ngx.req.set_header("connection", "Keep-Alive")
    elseif (connheader ~= nil and connheader ~= "close") then
         ngx.log(ngx.ERR,"src webservice connection header is not null"..connheader)
       -- ngx.header["connection"] = nil
         ngx.req.set_header("connection", "")
    end

Even ngx.req.set_header("connection", "Keep-Alive") is executed, at the upstream server log, I still find that "connection: close".

Why? Any suggestion?

Thanks
tjliupeng