How to make the openresty support parse the TCP stream and set the proxy address about stream-lua-nginx-module

[agentzh]

@daxiong380380 Just use content_by_lua* of ngx_stream_lua_module and implement the proxy all in Lua via cosockets.

[daxiong380380]

@agentzh
Hi
I had tried this method.
Cosockets can't satisfy my requirements,because cosockets just builds short TCP connection with the server,there exist a big performance problem.I want to use the upstream ability of nginx.

[splitice]

I must say we currently find ourselves in a similar situation. The performance of content_by_lua for implementing a filtering proxy just isnt very high.

I have planned body_filter_by_lua at some point, but currently its not even a remote priority.

[daxiong380380]

@agentzh
After I read some cosocket docs,I find my recognize to the cosoket is wrang.Maybe cosoket can solve my problem:)

[daxiong380380]

@agentzh
@splitice
Hi
when I create tcp socket during the content phase,I'd like to save this socket so that I can reuse it in the next requst,is this idea correctly?
or are there some other ways to reuse the socket in several request?

[agentzh]

@daxiong380380 Reusing connections is easy on both sides. For upstream connections, you can use the builtin connection pool via the setkeepalive method. This way you can recycle upstream connections across the "session" boundary (though not across the nginx worker process boundary). For downstream connections, just repeatedly process N requests in the same downstream cosocket object in a loop or something. Just do not use an infinite loop to process infinite number of requests in the same connection since right now quite some (small) memory blocks are allocated in the "session" memory pool, which won't get freed until the current session (associated with the current downstream connection) is destroyed.

[agentzh]

@splitice Have you sampled some flame graphs to show us? Please see http://openresty.org/en/profiling.html

[daxiong380380]

@agentzh
Hi
`--do it in the content

local socket = ngx.socket.tcp()

socket:setkeepalive(0)

local ok, err = socket:connect(ip,port)`

I create soket during the content phase,I expect the tcp connection keep alive always with the server so that I can reuse it in the different requsts,but when I test my deamo ,I find the tcp connection would be closed after one request finished.I think I use the cosocket in an incorrect way.
So your examples are very grateful .

[zyxtomcat]

setkeepalive must after the request finished, like this:
local socket = ngx.socket.tcp()
local ok, err = socket:connect(ip,port)
--request
socket:setkeepalive(...)

[daxiong380380]

@zyxtomcat
Thank you very much, I made a mistake, when I set keepalive after connect,the connection is not closed.

[daxiong380380]

@zyxtomcat
Hi
when I use the cosocket to forward my tcp stream I find the connection between my client and the nginx closed after the client received the response from the server.I hope that connection can also be keep alive,how can I do that?

[daxiong380380]

@agentzh
Hi
local sock = assert(ngx.req.socket(true))
Can I keep alive this socket,so I can keep the TCP connection between client and nginx.

[agentzh]

@daxiong380380 Just use a Lua loop to repeatedly process N requests in a single Lua handler. But it's not recommended to use an infinite loop or a finite loop with too many iterations.

[agentzh]

@daxiong380380 BTW, general questions should go to the openresty-en mailing list instead. This place is for bug report or developer discussions only. See http://openresty.org/en/community.html