22bd92a87f
QUIC pacing was recently implemented to limit burst and improve overall bandwidth. This is used only for MUX STREAM emission. Pacing requires nanosecond resolution. As such, it used now_cpu_time() which relies on clock_gettime() syscall. The usage of clock_gettime() has several drawbacks : * it is a syscall and thus requires a context-switch which may hurt performance * it is not be available on all systems * timestamp is retrieved multiple times during a single task execution, thus yielding different values which may tamper pacing calculation Improve this by using task_mono_time() instead. This returns task call time from the scheduler thread context. It requires the flag TASK_F_WANTS_TIME on QUIC MUX tasklet to force the scheduler to update call time with now_mono_time(). This solves every limitations listed above : * syscall invokation is only performed once before tasklet execution, thus reducing context-switch impact * on non compatible system, a millisecond timer is used as a fallback which should ensure that pacing works decently for them * timer value is now guaranteed to be fixed duing task execution
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.