Since 9c91b30 ("MINOR: server: remove prev_deleted server list"), hlua server pair iterator may use and return invalid (stale) server pointer if multiple servers were deleted between two iterations. Indeed, the server refcount mechanism (using srv_take()) is no longer sufficient as the prev_deleted mitigation was removed. To ensure server pointer consistency between two yields, the new watcher mechanism must be used (as it already the case for stats dumping). Thus in this patch we slightly change the server iteration logic: hlua_server_list_iterator_context struct now stores the next valid server pointer, and a watcher is added to ensure this pointer is never stale. Then in hlua_listable_servers_pairs_iterator(), this next pointer is used to create the Lua server object, and the next valid pointer is obtained by leveraging watcher_next(). No backport needed unless 9c91b30 ("MINOR: server: remove prev_deleted server list") is. Please note that dynamic servers were not supported in Lua prior to 2.8, so it doesn't make sense to backport this patch further than 2.8.
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.