upstream/haproxy
1
0
Fork 0
mirror of https://github.com/haproxy/haproxy.git synced 2026-03-09 01:20:40 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions 3
HAProxy - Load balancer
19610 commits 26 branches 410 tags 317 MiB
C 98.1%
Shell 0.9%
Makefile 0.5%
Lua 0.2%
Python 0.1%
Find a file
Aurelien DARRAGON 7f01f0a8ef BUG/MEDIUM: proxy/sktable: prevent watchdog trigger on soft-stop 
During soft-stop, manage_proxy() (p->task) will try to purge
trashable (expired and not referenced) sticktable entries,
effectively releasing the process memory to leave some space
for new processes.

This is done by calling stktable_trash_oldest(), immediately
followed by a pool_gc() to give the memory back to the OS.

As already mentioned in dfe7925 ("BUG/MEDIUM: stick-table:
limit the time spent purging old entries"), calling
stktable_trash_oldest() with a huge batch can result in the function
spending too much time searching and purging entries, and ultimately
triggering the watchdog.

Lately, an internal issue was reported in which we could see
that the watchdog is being triggered in stktable_trash_oldest()
on soft-stop (thus initiated by manage_proxy())

According to the report, the crash seems to only occur since 5938021
("BUG/MEDIUM: stick-table: do not leave entries in end of window during purge")

This could be the result of stktable_trash_oldest() now working
as expected, and thus spending a large amount of time purging
entries when called with a large enough <to_batch>.

Instead of adding new checks in stktable_trash_oldest(), here we
chose to address the issue directly in manage_proxy().

Since the stktable_trash_oldest() function is called with
<to_batch> == <p->table->current>, it's pretty obvious that it could
cause some issues during soft-stop if a large table, assuming it is
full prior to the soft-stop, suddenly sees most of its entries
becoming trashable because of the soft-stop.

Moreover, we should note that the call to stktable_trash_oldest() is
immediately followed by a call to pool_gc():

We know for sure that pool_gc(), as it involves malloc_trim() on
glibc, is rather expensive, and the more memory to reclaim,
the longer the call.

We need to ensure that both stktable_trash_oldest() + consequent
pool_gc() call both theoretically fit in a single task execution window
to avoid contention, and thus prevent the watchdog from being triggered.

To do this, we now allocate a "budget" for each purging attempt.
budget is maxed out to 32K, it means that each sticktable cleanup
attempt will trash at most 32K entries.

32K value is quite arbitrary here, and might need to be adjusted or
even deducted from other parameters if this fails to properly address
the issue without introducing new side-effects.
The goal is to find a good balance between the max duration of each
cleanup batch and the frequency of (expensive) pool_gc() calls.

If most of the budget is actually spent trashing entries, then the task
will immediately be rescheduled to continue the purge.
This way, the purge is effectively batched over multiple task runs.

This may be slowly backported to all stable versions.
[Please note that this commit depends on 6e1fe25 ("MINOR: proxy/pool:
prevent unnecessary calls to pool_gc()")]
2023-03-31 07:05:08 +02:00
.github CI: Reformat matrix.py using black 2023-01-03 16:28:34 +01:00
addons MINOR: stconn: Always report READ/WRITE event on shutr/shutw 2023-02-22 15:59:16 +01:00
admin BUILD: halog: fix missing double-quote at end of help line 2022-11-25 11:11:41 +01:00
dev MEDIUM: ring: make the offset relative to the head/tail instead of absolute 2023-02-24 09:26:30 +01:00
doc MINOR: http_fetch: Add case-insensitive argument for url_param/urlp_val 2023-03-30 14:11:25 +02:00
examples EXAMPLES: remove completely outdated acl-content-sw.cfg 2022-05-30 18:14:24 +02:00
include MINOR: http_fetch: add case insensitive support for smp_fetch_url_param 2023-03-30 14:11:10 +02:00
reg-tests REGTESTS : Add test support for case insentitive for url_param 2023-03-30 15:32:14 +02:00
scripts SCRIPTS: run-regtests: add a version check 2022-11-30 18:44:33 +01:00
src BUG/MEDIUM: proxy/sktable: prevent watchdog trigger on soft-stop 2023-03-31 07:05:08 +02:00
tests TESTS: add a unit test for one_among_mask() 2022-06-21 20:29:57 +02:00
.cirrus.yml CI: cirrus-ci: bump FreeBSD image to 13-1 2022-09-09 13:30:17 +02:00
.gitattributes MINOR: Configure the cpp userdiff driver for *.[ch] in .gitattributes 2021-02-22 18:17:57 +01:00
.gitignore CLEANUP: exclude udp-perturb with .gitignore 2022-09-16 15:47:04 +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
CHANGELOG [RELEASE] Released version 2.8-dev6 2023-03-28 13:58:56 +02:00
CONTRIBUTING CLEANUP: assorted typo fixes in the code and comments 2021-08-16 12:37:59 +02:00
INSTALL MINOR: version: mention that it's development again 2022-12-01 15:24:10 +01:00
LICENSE LICENSE: add licence exception for OpenSSL 2012-09-07 13:52:26 +02:00
MAINTAINERS CLEANUP: assorted typo fixes in the code and comments 2022-11-30 14:02:36 +01:00
Makefile BUILD: da: extends CFLAGS to support API v3 from 3.1.7 and onwards. 2023-03-28 08:40:34 +02:00
README DOC: create a BRANCHES file to explain the life cycle 2019-06-15 22:00:14 +02:00
SUBVERS BUILD: use format tags in VERDATE and SUBVERS files 2013-12-10 11:22:49 +01:00
VERDATE [RELEASE] Released version 2.8-dev6 2023-03-28 13:58:56 +02:00
VERSION [RELEASE] Released version 2.8-dev6 2023-03-28 13:58:56 +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)