90441e9bfe
When "vary" is enabled, we can have multiple entries for a given primary key in the cache tree. There is a limit to how many secondary entries can be inserted for a given key. When we try to insert a new secondary entry, if the limit is already reached, we can try to find expired entries with the same primary key, and if the limit is still reached we want to abort the current insertion and to remove the node that was just inserted. In commit "a29b073: MEDIUM: cache: Add refcount on cache_entry" though, a regression was introduced. Instead of removing the entry just inserted as the comments suggested, we removed the second to last entry and returned NULL. We then reset the eb.key of the cache_entry in the caller because we assumed that the entry was already removed from the tree. This means that some entries with an empty key were wrongly kept in the tree and the last secondary entry, which keeps the number of secondary entries of a given key was removed. This ended up causing some crashes later on when we tried to iterate over the elements of this given key. The crash could occur in multiple places, either when trying to retrieve an entry or to add some new ones. This crash was raised in GitHub issue #2950. The fix should be backported up to 3.0.
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.