b500e84e24
Since the beginning of thread support, the shutdown of streams attached to a server was run under the server's lock, but that's not sufficient. It indeed turns out that shutting down streams (either from the CLI using "shutdown sessions server XXX" or due to "on-error shutdown-sessions") iterates over all the streams to shut them down, but stream_shutdown() has no way to protect its actions against concurrent actions from the stream itself on another thread, and streams offer no such provisions anyway. The impact is some rare but possible crashes when shutting down streams from the CLI in cmopetition with high server traffic. The probability is low enough to mark it minor, though it was observed in the field. At least since 2.4 the streams are arranged in per-thread lists, so it likely would be possible using the event subsystem to delegate these events to dedicated per-thread tasks which would address the problem. But server streams don't get killed often enough to justify such extra complexity, so better just run the loop under thread isolation. It also shows that the internal API could probably be improved to support a lighter thread exclusion instead of full isolation: various places want to only exclude one thread and here it could work. But again there's no point doing this for now. This patch should be backported to all stable branches. It's important to carefully check that this srv_shutdowns_streams() function is never called itself under isolation in older versions (though at first glance it looks OK).
HAProxy
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:
- 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)
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.