* [ANN] yahns 1.13.0 -_- sleepy app server for Ruby
@ 2016-08-05 7:44 5% Eric Wong
0 siblings, 0 replies; 3+ results
From: Eric Wong @ 2016-08-05 7:44 UTC (permalink / raw)
To: ruby-talk; +Cc: yahns-public
A Free Software, multi-threaded, non-blocking network
application server designed for low _idle_ power consumption.
It is primarily optimized for applications with occasional users
which see little or no traffic. yahns currently hosts Rack/HTTP
applications, but may eventually support other application
types. Unlike some existing servers, yahns is extremely
sensitive to fatal bugs in the applications it hosts.
* git clone git://yhbt.net/yahns
* https://yahns.yhbt.net/README
* https://yahns.yhbt.net/NEWS.atom.xml
* we only accept plain-text email yahns-public@yhbt.net
* and archive all the mail we receive: https://yhbt.net/yahns-public/
* nntp://news.public-inbox.org/inbox.comp.lang.ruby.yahns
lrg nabgure ubeevoyl-anzrq freire :>
Changes:
yahns 1.13.0 - some user-visible improvements...
And probably a billion new regressions!
yahns now allows users to skip the Rack::Head, Rack::Chunked and
Rack::ContentLength middlewares to ease migrating from/to other
real-world Rack HTTP servers. Most notably, our chunked
encoding implementation is a bit faster than Rack::Chunked by
taking advantage of the writev(2) syscall:
https://yhbt.net/yahns-public/20160803031906.14553-4-e@80x24.org/
There's also rack 2.x fixes in the test case and extras/ section
(these incompatibilities did not affect existing users unless
they use the wonky extras/ section).
There's also some graceful shutdown fixes, the process title is
now changed to display the number of live FDs.
Of course, there's the usual round of documentation improvements
which are systemd and OpenSSL setup-related this time around.
However, the majority of changes (proxy_*, wbuf_lite), affect
currently-unadvertised functionality which is subject to removal
or incompatible config changes. However, they are used to serve
our mailing list archives at:
https://yhbt.net/yahns-public/
49 changes since yahns 1.12.5:
proxy_pass: simplify writing request bodies upstream
proxy_pass: hoist out proxy_res_headers method
proxy_pass: simplify proxy_http_response
proxy_pass: split out body and trailer reading in response
proxy_pass: trim down proxy_response_finish, too
proxy_pass: split out req_res into a separate file
proxy_pass: fix resumes after complete buffering is unblocked
proxy_pass: X-Forwarded-For appends to existing list
proxy_pass: pass entire object to proxy_http_response
proxy_pass: support "proxy_buffering: false"
proxy_pass: remove unnecessary rescue
req_res: store proxy_pass object here, instead
proxy_pass: redo "proxy_buffering: false"
wbuf: remove needless "busy" parameter
Merge branch 'maint'
extras/try_gzip_static: do not show backtrace on syscall errors
wbuf: remove tmpdir parameter
wbuf_lite: fix write retries for OpenSSL sockets
test_proxy_pass_no_buffering: fix racy test
queue_*: check for closed IO objects
cleanup graceful shutdown handling
proxy_pass: more descriptive error messages
proxy_pass: fix HTTP/1.0 backends on EOF w/o buffering
wbuf_common: reset offset counter when done
extras/try_gzip_static: resolve symlinks
test_ssl: remove unnecessary priv_key DH parameter
openssl_client: wrap shutdown for graceful termination
proxy_pass: keep trailer buffer on blocked client writes
proxy_pass: avoid TOCTTOU race when unbuffering, too
proxy_pass: avoid accessing logger in env after hijacking
proxy_pass: avoid stuck responses in "proxy_buffering: false"
extras: include status messages in responses
update init and add systemd examples
test_proxy_pass_no_buffering: exclude rb/ru files, too
wbuf_lite: use StringIO instead of TmpIO
wbuf_lite: truncate StringIO when done
wbuf_lite: prevent clobbering responses
wbuf_lite: unify EOF error handling
wbuf_lite: reset sf_offset/sf_count consistently
wbuf_lite: clear @busy flag when re-arming
http_response: drop bodies for non-compliant responses
fix rack 2.x compatibility bugs
doc: add session cache usage to OpenSSL example
test: skip some buffering tests on non-default values
response: drop clients after HTTP responses of unknown length
response: reduce stack overhead for parameter passing
response: support auto-chunking for HTTP/1.1
Revert "document Rack::Chunked/ContentLength semi-requirements"
extras/exec_cgi: fix for HTTPoxy vulnerability
Please note the disclaimer:
yahns is extremely sensitive to fatal bugs in the apps it hosts. There
is no (and never will be) any built-in "watchdog"-type feature to kill
stuck processes/threads. Each yahns process may be handling thousands
of clients; unexpectedly killing the process will abort _all_ of those
connections. Lives may be lost!
yahns hackers are not responsible for your application/library bugs.
Use an application server which is tolerant of buggy applications
if you cannot be bothered to fix all your fatal bugs.
--
EW
^ permalink raw reply [relevance 5%]
* [PATCH 1/7] proxy_pass: simplify writing request bodies upstream
2016-05-16 1:43 7% [PATCH 0/7] proxy_pass cleanups Eric Wong
@ 2016-05-16 1:43 5% ` Eric Wong
0 siblings, 0 replies; 3+ results
From: Eric Wong @ 2016-05-16 1:43 UTC (permalink / raw)
To: yahns-public
The cost of extra branches inside a loop is negligible compared
to the cost of all the other method calls we make. Favor
smaller code instead and inline some (now) single-use methods.
Furthermore, this allows us to reuse the request header buffer
instead of relying on thread-local storage and potentially
having to to swap buffers.
---
lib/yahns/proxy_pass.rb | 112 +++++++++++++++++++++---------------------------
1 file changed, 49 insertions(+), 63 deletions(-)
diff --git a/lib/yahns/proxy_pass.rb b/lib/yahns/proxy_pass.rb
index 148957b..a2d7d81 100644
--- a/lib/yahns/proxy_pass.rb
+++ b/lib/yahns/proxy_pass.rb
@@ -22,12 +22,6 @@ def req_start(c, req, input, chunked)
Thread.current[:yahns_queue].queue_add(self, Yahns::Queue::QEV_WR)
end
- # we must reinitialize the thread-local rbuf if it may get beyond the
- # current thread
- def detach_rbuf!
- Thread.current[:yahns_rbuf] = ''.dup
- end
-
def yahns_step # yahns event loop entry point
c = @yahns_client
case req = @rrstate
@@ -42,7 +36,9 @@ def yahns_step # yahns event loop entry point
if res = req.headers(@hdr = [], rv)
return c.proxy_response_start(res, rv, req, self)
else # ugh, big headers or tricked response
- buf = detach_rbuf!
+ # we must reinitialize the thread-local rbuf if it may
+ # live beyond the current thread
+ buf = Thread.current[:yahns_rbuf] = ''.dup
@resbuf = rv
end
# continue looping in middle "case @resbuf" loop
@@ -83,64 +79,63 @@ def yahns_step # yahns event loop entry point
c.proxy_err_response(502, self, e, wbuf)
end
- # returns :wait_readable if complete, :wait_writable if not
- def send_req_body(req)
- buf, input, chunked = req
-
- # get the first buffered chunk or vector
+ def send_req_body_chunk(buf)
case rv = String === buf ? kgio_trywrite(buf) : kgio_trywritev(buf)
when String, Array
- buf = rv # retry inner loop
- when :wait_writable
- req[0] = buf
- return :wait_writable
- when nil
- break # onto writing body
+ buf.replace(rv) # retry loop on partial write
+ when :wait_writable, nil
+ # :wait_writable = upstream is reading slowly and making us wait
+ return rv
+ else
+ abort "BUG: #{rv.inspect} from kgio_trywrite*"
end while true
+ end
- buf = Thread.current[:yahns_rbuf]
+ # returns :wait_readable if complete, :wait_writable if not
+ def send_req_body(req) # @rrstate == [ (str|vec), rack.input, chunked? ]
+ buf, input, chunked = req
- # Note: input (env['rack.input']) is fully-buffered by default so
- # we should not be waiting on a slow network resource when reading
- # input. However, some weird configs may disable this on LANs
+ # send the first buffered chunk or vector
+ rv = send_req_body_chunk(buf) and return rv # :wait_writable
+ # yay, sent the first chunk, now read the body!
+ rbuf = buf
if chunked
- while input.read(0x2000, buf)
- vec = [ "#{buf.size.to_s(16)}\r\n", buf, "\r\n".freeze ]
- case rv = kgio_trywritev(vec)
- when Array
- vec = rv # partial write, retry in case loop
- when :wait_writable
- detach_rbuf!
- req[0] = vec
- return :wait_writable
- when nil
- break # continue onto reading next chunk
- end while true
+ if String === buf # initial body
+ req[0] = buf = []
+ else
+ # try to reuse the biggest non-frozen buffer we just wrote;
+ rbuf = buf.max_by(&:size)
+ rbuf = ''.dup if rbuf.frozen? # unlikely...
end
- close_req_body(input)
-
- # note: we do not send any trailer, they are folded into the header
- # because this relies on full request buffering
- send_req_buf("0\r\n\r\n".freeze)
- # prepare_wait_readable already called by send_req_buf
- else # identity request, easy:
- while input.read(0x2000, buf)
- case rv = kgio_trywrite(buf)
- when String
- buf = rv # partial write, retry in case loop
- when :wait_writable
- detach_rbuf!
- req[0] = buf
- return :wait_writable
- when nil
- break # continue onto reading next block
- end while true
+ end
+
+ # Note: input (env['rack.input']) is fully-buffered by default so
+ # we should not be waiting on a slow network resource when reading
+ # input. However, some weird configs may disable this on LANs
+ # and we may wait indefinitely on input.read here...
+ while input.read(0x2000, rbuf)
+ if chunked
+ buf[0] = "#{rbuf.size.to_s(16)}\r\n".freeze
+ buf[1] = rbuf
+ buf[2] = "\r\n".freeze
end
+ rv = send_req_body_chunk(buf) and return rv # :wait_writable
+ end
+
+ rbuf.clear # all done, clear the big buffer
- close_req_body(input)
- prepare_wait_readable
+ # we cannot use respond_to?(:close) here since Rack::Lint::InputWrapper
+ # tries to prevent that (and hijack means all Rack specs go out the door)
+ case input
+ when Yahns::TeeInput, IO
+ input.close
end
+
+ # note: we do not send any trailer, they are folded into the header
+ # because this relies on full request buffering
+ # prepare_wait_readable is called by send_req_buf
+ chunked ? send_req_buf("0\r\n\r\n".freeze) : prepare_wait_readable
rescue Errno::EPIPE, Errno::ECONNRESET, Errno::ENOTCONN
# no more reading off the client socket, just prepare to forward
# the rejection response from the upstream (if any)
@@ -153,15 +148,6 @@ def prepare_wait_readable
:wait_readable # all done sending the request, wait for response
end
- def close_req_body(input)
- # we cannot use respond_to?(:close) here since Rack::Lint::InputWrapper
- # tries to prevent that (and hijack means all Rack specs go out the door)
- case input
- when Yahns::TeeInput, IO
- input.close
- end
- end
-
# n.b. buf must be a detached string not shared with
# Thread.current[:yahns_rbuf] of any thread
def send_req_buf(buf)
^ permalink raw reply related [relevance 5%]
* [PATCH 0/7] proxy_pass cleanups
@ 2016-05-16 1:43 7% Eric Wong
2016-05-16 1:43 5% ` [PATCH 1/7] proxy_pass: simplify writing request bodies upstream Eric Wong
0 siblings, 1 reply; 3+ results
From: Eric Wong @ 2016-05-16 1:43 UTC (permalink / raw)
To: yahns-public
A bunch of cleanups to hopefully make the proxy_pass-related
code a little saner and easier-to-follow.
I introduced at least one bug during this series which got fixed
in 7/7.
Extra sets of eyes to review would be greatly appreciated, thanks!
And this is running live and serving critical information to
readers of https://yhbt.net/ in all its glory!
Once I'm reasonably satisfied with this; I'll continue work
on making "proxy_buffering: false" work, so slow-client-capable
upstreams can generate gigantic (hundreds of megabytes!)
responses without filesystem overhead.
But first, I think I should work on making those gigantic
responses cheaper in terms of memory/CPU usage outside of
yahns. This is git-http-backend for serving mega repos
over smart HTTP, yahns is already great for dumb HTTP
git clones.
lib/yahns/proxy_http_response.rb | 236 +++++++++++++++------------------------
lib/yahns/proxy_pass.rb | 171 +---------------------------
lib/yahns/req_res.rb | 159 ++++++++++++++++++++++++++
3 files changed, 252 insertions(+), 314 deletions(-)
Eric Wong (7):
proxy_pass: simplify writing request bodies upstream
proxy_pass: hoist out proxy_res_headers method
proxy_pass: simplify proxy_http_response
proxy_pass: split out body and trailer reading in response
proxy_pass: trim down proxy_response_finish, too
proxy_pass: split out req_res into a separate file
proxy_pass: fix resumes after complete buffering is unblocked
^ permalink raw reply [relevance 7%]
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2016-08-05 7:44 5% [ANN] yahns 1.13.0 -_- sleepy app server for Ruby Eric Wong
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