haproxy/doc
Amaury Denoyelle 7232677385 MAJOR: server: do not remove idle conns in del server
Do not remove anymore idle and purgeable connections directly under the
"del server" handler. The main objective of this patch is to reduce the
amount of work performed under thread isolation. This should improve
"del server" scheduling with other haproxy tasks.

Another objective is to be able to properly support dynamic servers with
QUIC. Indeed, takeover is not yet implemented for this protocol, hence
it is not possible to rely on cleanup of idle connections performed by a
single thread under "del server" handler.

With this change it is not possible anymore to remove a server if there
is still idle connections referencing it. To ensure this cannot be
performed, srv_check_for_deletion() has been extended to check server
counters for idle and idle private connections.

Server deletion should still remain a viable procedure, as first it is
mandatory to put the targetted server into maintenance. This step forces
the cleanup of its existing idle connections. Thanks to a recent change,
all finishing connections are also removed immediately instead of
becoming idle. In short, this patch transforms idle connections removal
from a synchronous to an asynchronous procedure. However, this should
remain a steadfast and quick method achievable in less than a second.

This patch is considered major as some users may notice this change when
removing a server. In particular with the following CLI commands
pipeline:
  "disable server <X>; shutdown sessions server <X>; del server <X>"

Server deletion will now probably fail, as idle connections purge cannot
be completed immediately. Thus, it is now highly advise to always use a
small delay "wait srv-removable" before "del server" to ensure that idle
connections purge is executed prior.

Along with this change, documentation for "del server" and related
"shutdown sessions server" has been refined, in particular to better
highlight under what conditions a server can be removed.
2025-08-28 15:08:35 +02:00
..
design-thoughts CLEANUP: assorted typo fixes in the code and comments 2025-04-02 11:12:20 +02:00
internals MINOR: tools: also implement ha_aligned_alloc_typed() 2025-08-13 17:37:08 +02:00
lua-api CLEANUP: assorted typo fixes in the code, commits and doc 2025-07-10 19:49:48 +02:00
51Degrees-device-detection.txt DOC: 51d: updated 51Degrees repo URL for v3.2.10 2023-11-23 16:26:13 +01:00
acl.fig [DOC] add diagrams of queuing and future ACL design 2009-02-22 16:46:38 +01:00
coding-style.txt DOC: fix a few remainig cases of "Haproxy" and "HAproxy" in doc and comments 2021-05-09 06:50:46 +02:00
configuration.txt DOC: configuration: clarify 'default-crt' and implicit default certificates 2025-08-27 17:09:02 +02:00
cookie-options.txt DOC: fix a few typos in the documentation 2018-11-18 22:23:15 +01:00
DeviceAtlas-device-detection.txt DOC: deviceatlas build clarifications 2025-07-03 09:08:06 +02:00
gpl.txt [LICENSE] licensing clarifications 2006-06-15 21:48:13 +02:00
haproxy.1 DOC: add description of pidfile in master-worker mode 2020-08-26 18:40:53 +02:00
HAProxyCommunityEdition_60px.png DOC: replace the README by a markdown version 2024-05-30 13:53:46 +02:00
intro.txt [RELEASE] Released version 3.3-dev0 2025-05-28 16:46:34 +02:00
lgpl.txt [LICENSE] licensing clarifications 2006-06-15 21:48:13 +02:00
linux-syn-cookies.txt DOC: add doc/linux-syn-cookies.txt 2015-08-11 12:17:41 +02:00
lua.txt [RELEASE] Released version 3.1-dev6 2024-08-21 17:50:03 +02:00
management.txt MAJOR: server: do not remove idle conns in del server 2025-08-28 15:08:35 +02:00
netscaler-client-ip-insertion-protocol.txt DOC: fix typos 2019-05-25 07:34:24 +02:00
network-namespaces.txt MAJOR: namespace: add Linux network namespace support 2014-11-21 07:51:57 +01:00
peers-v2.0.txt MEDIUM: stick-tables: add a new stored type for glitch_cnt and glitch_rate 2024-02-08 15:51:49 +01:00
peers.txt CLEANUP: assorted typo fixes in the code and comments 2022-12-07 09:08:18 +01:00
proxy-protocol.txt DOC: proxy-protocol: fix wrong byte in provided example 2023-02-12 09:26:48 +01:00
queuing.fig [DOC] add diagrams of queuing and future ACL design 2009-02-22 16:46:38 +01:00
regression-testing.txt CLEANUP: assorted typo fixes in the code and comments 2023-11-23 16:23:14 +01:00
seamless_reload.txt CLEANUP: removed obsolete examples an move a few to better places 2019-06-15 21:25:06 +02:00
SOCKS4.protocol.txt MEDIUM: connection: Upstream SOCKS4 proxy support 2019-05-31 17:24:06 +02:00
SPOE.txt CLEANUP: assorted typo fixes in the code, commits and doc 2025-04-03 11:37:25 +02:00
WURFL-device-detection.txt CONTRIB: move src/wurfl.c and contrib/wurfl to addons/wurfl 2021-04-02 17:48:42 +02:00