5c299dee5a
This patch looks huge, but it has a very simple goal: protect all accessed to shared stats pointers (either read or writes), because we know consider that these pointers may be NULL. The reason behind this is despite all precautions taken to ensure the pointers shouldn't be NULL when not expected, there are still corner cases (ie: frontends stats used on a backend which no FE cap and vice versa) where we could try to access a memory area which is not allocated. Willy stumbled on such cases while playing with the rings servers upon connection error, which eventually led to process crashes (since 3.3 when shared stats were implemented) Also, we may decide later that shared stats are optional and should be disabled on the proxy to save memory and CPU, and this patch is a step further towards that goal. So in essence, this patch ensures shared stats pointers are always initialized (including NULL), and adds necessary guards before shared stats pointers are de-referenced. Since we already had some checks for backends and listeners stats, and the pointer address retrieval should stay in cpu cache, let's hope that this patch doesn't impact stats performance much.
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.