HAProxy - Load balancer
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Christopher Faulet 0efc0993ec BUG/MEDIUM: resolvers: Don't release resolution from a requester callbacks
Another way to say it: "Safely unlink requester from a requester callbacks".

Requester callbacks must never try to unlink a requester from a resolution, for
the current requester or another one. First, these callback functions are called
in a loop on a request list, not necessarily safe. Thus unlink resolution at
this place, may be unsafe. And it is useless to try to make these loops safe
because, all this stuff is placed in a loop on a resolution list. Unlink a
requester may lead to release a resolution if it is the last requester.

However, the unkink is necessary because we cannot reset the server state
(hostname and IP) with some pending DNS resolution on it. So, to workaround
this issue, we introduce the "safe" unlink. It is only performed from a
requester callback. In this case, the unlink function never releases the
resolution, it only reset it if necessary. And when a resolution is found
with an empty requester list, it is released.

This patch depends on the following commits :

 * MINOR: resolvers: Purge answer items when a SRV resolution triggers an error
 * MINOR: resolvers: Use a function to remove answers attached to a resolution
 * MINOR: resolvers: Directly call srvrq_update_srv_state() when possible
 * MINOR: resolvers: Add function to change the srv status based on SRV resolution

All the series must be backported as far as 2.2. It fixes a regression
introduced by the commit b4badf720 ("BUG/MINOR: resolvers: new callback to
properly handle SRV record errors").

don't release resolution from requester cb
2021-03-12 17:41:28 +01:00
.github Revert "CI: Pin VTest to a known good commit" 2021-03-03 05:07:10 +01:00
contrib MINOR: contrib: Enhance peers dissector heuristic. 2021-03-02 11:08:45 +01:00
doc OPTIM: task: automatically adjust the default runqueue-depth to the threads 2021-03-10 11:15:34 +01:00
examples CLEANUP: assorted typo fixes in the code and comments 2020-06-26 11:27:28 +02:00
include BUG/MEDIUM: resolvers: Don't release resolution from a requester callbacks 2021-03-12 17:41:28 +01:00
reg-tests BUG/MINOR: sample: Rename SenderComID/TargetComID to SenderCompID/TargetCompID 2021-03-10 10:44:20 +01:00
scripts BUILD: Makefile: move REGTESTST_TYPE default setting 2021-02-05 11:41:16 +01:00
src BUG/MEDIUM: resolvers: Don't release resolution from a requester callbacks 2021-03-12 17:41:28 +01:00
tests MEDIUM: config: remove the deprecated and dangerous global "debug" directive 2020-10-09 19:18:45 +02:00
.cirrus.yml CI: cirrus: update FreeBSD image to 12.2 2021-02-12 16:04:52 +01:00
.gitattributes MINOR: Configure the cpp userdiff driver for *.[ch] in .gitattributes 2021-02-22 18:17:57 +01:00
.gitignore CLEANUP: Update .gitignore 2020-09-12 13:11:24 +02:00
.travis.yml CI: travis-ci: drop coverity scan builds 2020-12-22 19:39:23 +01:00
BRANCHES DOC: fix some spelling issues over multiple files 2021-01-08 14:53:47 +01:00
CHANGELOG [RELEASE] Released version 2.4-dev11 2021-03-05 21:24:23 +01:00
CONTRIBUTING DOC: fix some spelling issues over multiple files 2021-01-08 14:53:47 +01:00
INSTALL DOC: fix some spelling issues over multiple files 2021-01-08 14:53:47 +01:00
LICENSE LICENSE: add licence exception for OpenSSL 2012-09-07 13:52:26 +02:00
MAINTAINERS DOC: Update the module list in MAINTAINERS file 2021-02-24 22:09:57 +01:00
Makefile MINOR: build: force CC to set a return code when probing options 2021-03-09 15:24:47 +01:00
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 2.4-dev11 2021-03-05 21:24:23 +01:00
VERSION [RELEASE] Released version 2.4-dev11 2021-03-05 21:24:23 +01:00

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)