bbaa7aef7b
Previously, congestion window was increased any time each time a new acknowledge was received. However, it did not take into account the window filling level. In a network condition with negligible loss, this will cause the window to be incremented until the maximum value (by default 480k), even though the application does not have enough data to fill it. In most cases, this issue is not noticeable. However, it may lead to excessive memory consumption when a QUIC connection is suddendly interrupted, as in this case haproxy will fill the window with retransmission. It even has caused OOM crash when thousands of clients were interrupted at once on a local network benchmark. Fix this by first checking window level prior to every incrementation via a new helper function quic_cwnd_may_increase(). It was arbitrarily decided that the window must be at least 50% full when the ACK is handled prior to increment it. This value is a good compromise to keep window in check while still allowing fast increment when needed. Note that this patch only concerns cubic and newreno algorithm. BBR has already its notion of application limited which ensures the window is only incremented when necessary. This should be backported up to 2.6.
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.