fb7e5e1696
When two pointer hash to the same memprofile bin, we currently try again
with the same bin until we find a spare one or we reach the limit of 16.
Olivier suggested to try with a different step for different pointers so
as to limit the number of bins to visit in such a case, so let's split
the pointer hash calculation so that we keep the raw hash before reduction
and use its lowest bits as the retry step. We force lowest bit to 1 to
avoid integral multiples that would oscillate between only a few positions.
Quick tests with h1+h2 requests show that for ~744 distinct entries, we
used to have 1.17 retries per lookup before and 0.6 now so we're halving
the cost of hash collisions. A heavier workload that used to produce 920
entries with 2.01 retries per lookup now reaches 966 entries (94.3% usage
vs 89.8% before) with only 1.44 retries per lookup.
This should be safe to backport, but depends on this previous commit:
MINOR: tools: extend the pointer hashing code to ease manipulations
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.