a498e527b4
It is possible to miss a synchronous write event in process_stream() if the stream was woken up on a write event. In that case, it is possible to freeze the stream until the next I/O event or timeout. Concretely, the stream is woken up with CF_WRITE_EVENT on a channel. this flag is removed from the channel when we leave proces_stream(). But before leaving process_stream(), when a synchronous send is tried on this channel, the flag is removed and eventually set again on success. But this event is masked by the previous one, and the channel is not resync as it should be. To fix the bug, CF_READ_EVENT and CF_WRITE_EVENT flags are removed from a channel after the corresponding analysers evaluation. This way, we will be able to detect a successful synchronous send to restart analysers evaluation based on the new channel state. It is safe (or it should be) to do so becaues these flags are only used by analysers and tested to resync the stream inside process_stream(). It is a very old bug and I guess all versions are affected. It was observed on 2.9 and higher, and with the master/worker only. But it could affect any stream. It is tagged a MAJOR because this area is really sensitive to any change. This patch should fix the issue #3070. It should probably be backported to all stable versions, but only after a period of observation and with a special care because this area is really sensitive to changes. It is probably reasonnable to backport it as far as 3.0 and wait for older versions. Thanks to Valentine for its help on this issue !
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.