1824079fca
This is one of the rare pleasant surprises of fixing an almost 16-years
old bug that remained unnoticed since the feature was implemented. In
1.4-dev7, commit 3bd697e071 ("[MEDIUM] Add stick table (persistence)
management functions and types") introduced stick-tables with multiple
key types, including strings, IP addresses and integers. Entries are
coded in binary and their binary representation is indexed. A special
case was made for strings in order to index them as zero-terminated
strings. However, there's one subtlety. While strings indeed have a
zero appended, they're still indexed using ebmb_insert(), which means
that all the bytes till the configured size are indexed as well. And
while these bytes generally come from a temporary storage that often
contains zeroes, or that is longer than the configured string length
and will result in truncation, it's not always the case and certain
traffic patterns with certain configurations manage to occasionally
present unpadded strings resulting in apparent duplicate keys appearing
in the dump, as shown in GH issue #3161. It seems to be essentially
reproducible at boot, and not to be particularly affected by mixed
patterns. These keys are in fact not exact duplicates in memory, but
everywhere they're used (including during synchronization), they are
equal.
What's interesting is that when this happens, one key can be presented
to a peer with its own data and will be indexed as the only one, possibly
replacing contents from the previous key, which might replace them again
later once updated in turn. This is visible in the dump of the issue
above, where key "localhost:8001" was split into two entries, one with a
request count of one and the other with a request count of 499999, and
indeed, all peers see only that last value, which overwrote the first
one.
This fix must be backported to all stable branches. Special kudos to
Mark Wort for undelining that one.
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.