upstream/haproxy
1
0
Fork 0
mirror of https://github.com/haproxy/haproxy.git synced 2026-04-15 21:59:41 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions 3
HAProxy - Load balancer
22953 commits 30 branches 413 tags 227 MiB
C 98.1%
Shell 0.9%
Makefile 0.5%
Lua 0.2%
Python 0.1%
Find a file
Willy Tarreau b11495652e BUG/MEDIUM: queue: implement a flag to check for the dequeuing 
As unveiled in GH issue #2711, commit 5541d4995d ("BUG/MEDIUM: queue:
deal with a rare TOCTOU in assign_server_and_queue()") does have some
side effects in that it can occasionally cause an endless loop.

As Christopher analysed it, the problem is that process_srv_queue(),
which uses a trylock in order to leave only one thread in charge of
the dequeueing process, can lose the lock race against pendconn_add().
If this happens on the last served request, then there's no more thread
to deal with the dequeuing, and assign_server_and_queue() will loop
forever on a condition that was initially exepected to be extremely
rare (and still is, except that now it can become sticky). Previously
what was happening is that such queued requests would just time out
and since that was very rare, nobody would notice.

The root of the problem really is that trylock. It was added so that
only one thread dequeues at a time but it doesn't offer only that
guarantee since it also prevents a thread from dequeuing if another
one is in the process of queuing. We need a different criterion.

What we're doing now is to set a flag "dequeuing" in the server, which
indicates that one thread is currently in the process of dequeuing
requests. This one is atomically tested, and only if no thread is in
this process, then the thread grabs the queue's lock and dequeues.
This way it will be serialized with pendconn_add() and no request
addition will be missed.

It is not certain whether the original race covered by the fix above
can still happen with this change, so better keep that fix for now.

Thanks to @Yenya (Jan Kasprzak) for the precise and complete report
allowing to spot the problem.

This patch should be backported wherever the patch above was backported.
2024-09-13 08:35:47 +02:00
.github CI: QUIC Interop: use different artifact names for uploading logs 2024-08-26 11:19:41 +02:00
addons MINOR: startup: rename readcfgfile in parse_cfg 2024-08-07 18:41:41 +02:00
admin CLEANUP: assorted typo fixes in the code and comments 2024-09-03 17:49:21 +02:00
dev DEV: patchbot: detect commit IDs starting with 7 chars 2024-09-04 09:41:40 +02:00
doc MINOR: server: allow init-state for dynamic servers 2024-09-10 18:18:38 +02:00
examples MEDIUM: protocol: add MPTCP per address support 2024-08-30 18:53:49 +02:00
include BUG/MEDIUM: queue: implement a flag to check for the dequeuing 2024-09-13 08:35:47 +02:00
reg-tests REGTESTS: shorten a bit the delay for the h1/h2 upgrade test 2024-09-10 10:36:59 +02:00
scripts SCRIPTS: create-release: no more need to skip architecture.txt 2024-07-10 15:38:45 +02:00
src BUG/MEDIUM: queue: implement a flag to check for the dequeuing 2024-09-13 08:35:47 +02:00
tests MAJOR: import: update mt_list to support exponential back-off (try #2) 2024-07-09 16:46:38 +02:00
.cirrus.yml CI: FreeBSD: upgrade image, packages 2024-06-04 11:19:00 +02:00
.gitattributes MINOR: Configure the cpp userdiff driver for *.[ch] in .gitattributes 2021-02-22 18:17:57 +01:00
.gitignore CONTRIB: Add vi file extensions to .gitignore 2023-06-02 18:14:34 +02:00
.mailmap DOC: update Tim's address in .mailmap 2021-09-16 09:14:14 +02:00
.travis.yml CI: travis-ci: temporarily disable arm64 builds 2021-08-07 07:28:15 +02:00
BRANCHES DOC: fix some spelling issues over multiple files 2021-01-08 14:53:47 +01:00
BSDmakefile BUILD: makefile: commit the tiny FreeBSD makefile stub 2023-05-24 17:17:36 +02:00
CHANGELOG [RELEASE] Released version 3.1-dev7 2024-09-05 18:53:54 +02:00
CONTRIBUTING CLEANUP: assorted typo fixes in the code and comments 2021-08-16 12:37:59 +02:00
INSTALL DOC: install: don't reference removed CPU arg 2024-07-16 20:06:06 +02:00
LICENSE LICENSE: add licence exception for OpenSSL 2012-09-07 13:52:26 +02:00
MAINTAINERS MAJOR: spoe: Let the SPOE back into the game 2024-05-22 09:04:38 +02:00
Makefile MINOR: quic: Token for future connections implementation. 2024-08-30 17:04:09 +02:00
README.md DOC: change the link to the FreeBSD CI in README.md 2024-06-03 15:21:29 +02:00
SUBVERS BUILD: use format tags in VERDATE and SUBVERS files 2013-12-10 11:22:49 +01:00
VERDATE [RELEASE] Released version 3.1-dev7 2024-09-05 18:53:54 +02:00
VERSION [RELEASE] Released version 3.1-dev7 2024-09-05 18:53:54 +02:00

README.md

HAProxy

alpine/musl AWS-LC openssl no-deprecated Illumos NetBSD FreeBSD VTest

HAProxy logo

HAProxy is a free, very fast and reliable reverse-proxy offering high availability, load balancing, and proxying for TCP and HTTP-based applications.

Installation

The INSTALL file describes how to build HAProxy. A list of packages is also available on the wiki.

Getting help

The discourse and the mailing-list are available for questions or configuration assistance. You can also use the slack or IRC channel. Please don't use the issue tracker for these.

The issue tracker is only for bug reports or feature requests.

Documentation

The HAProxy documentation has been split into a number of different files for ease of use. It is available in text format as well as HTML. The wiki is also meant to replace the old architecture guide.

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:

License

HAProxy is licensed under GPL 2 or any later version, the headers under LGPL 2.1. See the LICENSE file for a more detailed explanation.