upstream/haproxy
1
0
Fork 0
mirror of https://github.com/haproxy/haproxy.git synced 2026-03-21 18:10:47 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions 4
HAProxy - Load balancer
12256 commits 27 branches 411 tags 327 MiB
C 98.1%
Shell 0.9%
Makefile 0.5%
Lua 0.2%
Python 0.1%
Find a file
Willy Tarreau 4cabfc18a3 BUG/MAJOR: connection: always disable ready events once reported 
This effectively reverts the two following commits:

  6f95f6e11 ("OPTIM: connection: disable receiving on disabled events when the run queue is too high")
  065a02561 ("MEDIUM: connection: don't stop receiving events in the FD handler")

The problem as reported in issue #662 is that when the events signals
the readiness of input data that has to be forwarded over a congested
stream, the mux will read data and wake the stream up to forward them,
but the buffer full condition makes this impossible immediately, then
nobody in the chain will be able to disable the event after it was
first reported. And given we don't know at the connection level whether
an event was already reported or not, we can't decide anymore to
forcefully stop it if for any reason its processing gets delayed.

The problem is magnified in issue #662 by the fact that a shutdown is
reported with pending data occupying the buffer. The shutdown will
strike in loops and cause the upper layer stream to be notified until
it's handled, but with a buffer full it's not possible to call cs_recv()
hence to purge the event.

All this can only be handled optimally by implementing a lower layer,
direct mux-to-mux forwarding that will not require any scheduling. This
was no wake up will be needed and the event will be instantly handled
or paused for a long time.

For now let's simply revert these optimizations. Running a 1 MB transfer
test over H2 using 8 connections having each 32 streams with a limited
link of 320 Mbps shows the following profile before this fix:

   calls  syscall       (100% CPU)
  ------  -------
  259878  epoll_wait
  519759  clock_gettime
   17277  sendto
   17129  recvfrom
     672  epoll_ctl

And the following one after the fix:

   calls  syscall       (2-3% CPU)
  ------  -------
   17201  sendto
   17357  recvfrom
    2304  epoll_wait
    4609  clock_gettime
    1200  epoll_ctl

Thus the behavior is much better.

No backport is needed as these patches were only in 2.2-dev.

Many thanks to William Dauchy for reporting a lot of details around this
difficult issue.
2020-06-17 17:00:51 +02:00
.github CI: extend spellchecker whitelist 2020-05-11 10:10:26 +02:00
contrib BUILD: include: add sys/types before netinet/tcp.h 2020-06-11 11:22:44 +02:00
doc [RELEASE] Released version 2.2-dev9 2020-06-11 10:22:10 +02:00
examples CLEANUP: removed obsolete examples an move a few to better places 2019-06-15 21:25:06 +02:00
include MINOR: compiler: always define __has_feature() 2020-06-16 19:13:24 +02:00
reg-tests MINOR: sample: Add secure_memcmp converter 2020-06-09 22:04:13 +02:00
scripts REORG: include: move version.h to haproxy/ 2020-06-11 10:18:56 +02:00
src BUG/MAJOR: connection: always disable ready events once reported 2020-06-17 17:00:51 +02:00
tests REORG: include: split mini-clist into haproxy/list and list-t.h 2020-06-11 10:18:56 +02:00
.cirrus.yml CI: cirrus-ci: skip reg-tests/connection/proxy_protocol_send_unique_id_alpn.vtc on CentOS 6 2020-05-28 16:51:36 +02:00
.gitignore DOC: create a BRANCHES file to explain the life cycle 2019-06-15 22:00:14 +02:00
.travis.yml CI: travis-ci: use "-O1" for clang builds 2020-06-13 22:59:03 +02:00
BRANCHES DOC: assorted typo fixes in the documentation 2020-03-09 14:45:58 +01:00
CHANGELOG [RELEASE] Released version 2.2-dev9 2020-06-11 10:22:10 +02:00
CONTRIBUTING DOC: assorted typo fixes in the documentation and Makefile 2020-03-06 10:49:55 +01:00
INSTALL BUILD: Makefile: add linux-musl to TARGET 2020-04-16 15:17:13 +02:00
LICENSE LICENSE: add licence exception for OpenSSL 2012-09-07 13:52:26 +02:00
MAINTAINERS REORG: include: split hathreads into haproxy/thread.h and haproxy/thread-t.h 2020-06-11 10:18:56 +02:00
Makefile BUILD: Re-enable -Wimplicit-fallthrough 2020-06-11 16:49:37 +02:00
README DOC: create a BRANCHES file to explain the life cycle 2019-06-15 22:00:14 +02:00
ROADMAP DOC: update the outdated ROADMAP file 2019-06-15 21:59:54 +02:00
SUBVERS BUILD: use format tags in VERDATE and SUBVERS files 2013-12-10 11:22:49 +01:00
VERDATE [RELEASE] Released version 2.2-dev9 2020-06-11 10:22:10 +02:00
VERSION [RELEASE] Released version 2.2-dev9 2020-06-11 10:22:10 +02:00

README 

The HAProxy documentation has been split into a number of different files for
ease of use.

Please refer to the following files depending on what you're looking for :

  - INSTALL for instructions on how to build and install HAProxy
  - BRANCHES to understand the project's life cycle and what version to use
  - LICENSE for the project's license
  - CONTRIBUTING for the process to follow to submit contributions

The more detailed documentation is located into the doc/ directory :

  - doc/intro.txt for a quick introduction on HAProxy
  - doc/configuration.txt for the configuration's reference manual
  - doc/lua.txt for the Lua's reference manual
  - doc/SPOE.txt for how to use the SPOE engine
  - doc/network-namespaces.txt for how to use network namespaces under Linux
  - doc/management.txt for the management guide
  - doc/regression-testing.txt for how to use the regression testing suite
  - doc/peers.txt for the peers protocol reference
  - doc/coding-style.txt for how to adopt HAProxy's coding style
  - doc/internals for developer-specific documentation (not all up to date)