Perf top showed that h1_snd_buf() was having great difficulties accessing
the proxy's server_id_hdr_name field in the middle of the headers loop.
Moving the assignment out of the loop to a local variable moved the
problem there as well:
| if (!(h1m->flags & H1_MF_RESP) && isttest(h1c->px->server_id_hdr_n
0.10 |20b0: mov -0x120(%rbp),%rdi
1.33 | mov 0x60(%rdi),%r10
0.01 | test %eax,%eax
0.18 | jne 2118
12.87 | mov 0x350(%r10),%rdi
0.01 | test %rdi,%rdi
0.05 | je 2118
| mov 0x358(%r10),%r11
It turns out that there are several atomically accessed fields in its
vicinity, causing the cache line to bounce all the time. Let's collect
the few frequently changed fields and place them together at the end
of the structure, and plug the 32-bit hole with another isolated field.
Doing so also reduced a little bit the cost of decrementing be->be_conn
in process_stream(), and overall the HTTP/1 performance increased by
about 1% both on ARM and x86_64.
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.
