a1f26ca307
Tests involving 0-RTT and H2 on the backend show that 0-RTT is being partially used but does not work. The analysis shows that only the preface and settings are sent using early-data and the request is sent separately. As explained in the previous patch, this is caused by the fact that a wakeup of the iocb is needed just to send the preface, then a new call to process_stream is needed to try sending again. Here with this patch, we're making h2_snd_buf() able to send the preface if it was not yet sent. Thanks to this, the preface, settings and first request can now leave as a single TCP segment. In case of TLS with 0-RTT, it now allows all the block to leave in early data. Even in clear-text H2, we're now seeing a 15% lower context-switch count, and the number of calls to process_stream() per connection dropped from 3 to 2. The connection rate increased by an extra 9.5%. Compared to without the last 3 patches, this is a 22% reduction of context-switches, 33% reduction of process_stream() calls, and 15.7% increase in connection rate. And more importantly, 0-RTT now really works with H2 on the backend, saving one full RTT on the first request. This fix is only for a missed optimization and a non-functional 0-RTT on the backend. It's worth backporting it, but it doesn't cause enough harm to hurry a backport. Better wait for it to live a little bit in 3.3 (till at least a week or two after the final release) before backporting it. It's not sure that it's worth going beyond 3.2 in any case. It depends on the these two previous commits: MEDIUM: mux-h2: do not needlessly refrain from sending data early MINOR: mux-h2: extract the code to send preface+settings into its own function
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.