[ANN] The HTTP/2 protocol implementation (client side)

zchao1995 · 2018-09-15T17:53:06+00:00

Hello, I get following request from a device and should proxy it to hd10.vtech.com: GET http://hd10.vtech.com/test/pp_firmware/HD10...

[ANN] The HTTP/2 protocol implementation (client side)

zchao1995

Hello!

Recently I created the lua-resty-http2, which implements the HTTP/2 protocol on the client side,

furthermore, now you can use the HTTP/2 protocol by lua-resty-requests easily! Welcome to report

issues and submit PRs.

However, there are some limitations that may limit the HTTP/2 power.

The Cosocket technology doesn't support the ALPN/NPN extensions when ssl handshaking,

as such we cannot use HTTP/2 over SSL/TLS, I have submitted a patch to the lua-resty-http2

to support the protocol upgrade, just as a temporary way.

The Cosocket model is request-related, this limits the reuse of the HTTP/2 session as we must

match the correct session with the reused connection, but it is difficult when your connection pool

contains more than one alive connection. Also the lua-resty-requests bypasses this, but the schema

is not elegant, which should be changed if there are better ways in the future.

There may still some potential issues inside both lua-resty-http2 and lua-resty-requests,

so again, PRs and Issues are welcome!

Best Regards

Alex Zhang

kiril

Hello Alex. I would like to hear more why it was important to implement HTTP/2 for upstreams? What do you think will be the benefit compared to HTTP/1.1 and keepalives?

Thank you in advance,

Kiril

On Saturday, September 15, 2018 at 5:53:06 AM UTC-4, tokers wrote:

Hello!

Recently I created the lua-resty-http2, which implements the HTTP/2 protocol on the client side,
furthermore, now you can use the HTTP/2 protocol by lua-resty-requests easily! Welcome to report
issues and submit PRs.

However, there are some limitations that may limit the HTTP/2 power.

The Cosocket technology doesn't support the ALPN/NPN extensions when ssl handshaking,
as such we cannot use HTTP/2 over SSL/TLS, I have submitted a patch to the lua-resty-http2
to support the protocol upgrade, just as a temporary way.

The Cosocket model is request-related, this limits the reuse of the HTTP/2 session as we must
match the correct session with the reused connection, but it is difficult when your connection pool
contains more than one alive connection. Also the lua-resty-requests bypasses this, but the schema
is not elegant, which should be changed if there are better ways in the future.

There may still some potential issues inside both lua-resty-http2 and lua-resty-requests,
so again, PRs and Issues are welcome!

Best Regards
Alex Zhang

zchao1995

Hello!

> Hello Alex. I would like to hear more why it was important to implement HTTP/2 for upstreams? What do you think will be the benefit compared to HTTP/1.1 and keepalives?

Well, firstly I must say there are some inherent advantages of HTTP/2, like the HPACK, which reduces the cost of headers parsing,

and the HOL blocking problem is solved, since HTTP/2 supports the concurrent streams, becasue sometimes you may need to communicate with

multiple upstream servers.

Also, with the HTTP/2 support, the usage of gRPC is possible.

However, there are still some limitations just like I said above (because of the ngx_lua modle). So the full power cannot be showed, at least for now.

So with this library, I hope the ecosystem of OpenResty can be more and more perfect.

302976474

Hello Alex. I would like to ask a question. I want to implement a push system through openresty,
accept the http request, and push it to the backend apns and fcm push server. Access to apns requires
the use of http2.0 rest api.I roughly read the implementation of lua-resty-http2,and found you use the single
size connection pool to bypass the limitation between the mapping of HTTP/2 session and the underlying
connection(client:keepalive).

So, my question is how can I keep two sessions, one to apns and one to fcm. apns use lua-resty-http2, fcm use lua-resty-http.
Do you have any good suggestion?

Best Regards

Rojeas Wang

On Saturday, September 15, 2018 at 5:53:06 PM UTC+8, tokers wrote:

Hello!

Recently I created the lua-resty-http2, which implements the HTTP/2 protocol on the client side,
furthermore, now you can use the HTTP/2 protocol by lua-resty-requests easily! Welcome to report
issues and submit PRs.

However, there are some limitations that may limit the HTTP/2 power.

The Cosocket technology doesn't support the ALPN/NPN extensions when ssl handshaking,
as such we cannot use HTTP/2 over SSL/TLS, I have submitted a patch to the lua-resty-http2
to support the protocol upgrade, just as a temporary way.

The Cosocket model is request-related, this limits the reuse of the HTTP/2 session as we must
match the correct session with the reused connection, but it is difficult when your connection pool
contains more than one alive connection. Also the lua-resty-requests bypasses this, but the schema
is not elegant, which should be changed if there are better ways in the future.

There may still some potential issues inside both lua-resty-http2 and lua-resty-requests,
so again, PRs and Issues are welcome!

Best Regards
Alex Zhang

zchao1995

Hello!

> Hello Alex. I would like to ask a question. I want to implement a push system through openresty,
> accept the http request, and push it to the backend apns and fcm push server. Access to apns requires
> the use of http2.0 rest api.I roughly read the implementation of lua-resty-http2,and found you use the single
> size connection pool to bypass the limitation between the mapping of HTTP/2 session and the underlying
> connection(client:keepalive).

Yes. This is an inherent limitation of cosocket.

> So, my question is how can I keep two sessions, one to apns and one to fcm. apns use lua-resty-http2, fcm use lua-resty-http.

> Do you have any good suggestion?

Maybe some efforts are needed to let lua-resty-http supports this.

BTW, my lua-resty-requests supports the HTTP/2 protocol.

You can try it first, although some bugs may in there.

302976474

got, thanks a lot

Best Regards
Rojeas Wang

On Friday, February 22, 2019 at 2:19:02 PM UTC+8, tokers wrote:

Hello!

> Hello Alex. I would like to ask a question. I want to implement a push system through openresty,
> accept the http request, and push it to the backend apns and fcm push server. Access to apns requires
> the use of http2.0 rest api.I roughly read the implementation of lua-resty-http2,and found you use the single
> size connection pool to bypass the limitation between the mapping of HTTP/2 session and the underlying
> connection(client:keepalive).

Yes. This is an inherent limitation of cosocket.

> So, my question is how can I keep two sessions, one to apns and one to fcm. apns use lua-resty-http2, fcm use lua-resty-http.
> Do you have any good suggestion?

Maybe some efforts are needed to let lua-resty-http supports this.
BTW, my lua-resty-requests supports the HTTP/2 protocol.
You can try it first, although some bugs may in there.