27236f2218
As reported by Lukas Tribus on the mailing list [1], trying to connect to a nameserver with invalid network settings causes haproxy to retry a new connection attempt immediately which eventually causes unexpected CPU usage on the thread responsible for the applet (namely 100% on one CPU will be observed). This can be reproduced with the test config below: resolvers default nameserver ns1 tcp4@8.8.8.8:53 source 192.168.99.99 listen listen mode http bind :8080 server s1 www.google.com resolvers default init-addr none To fix this the issue, we add a temporisation of one second between a new connection attempt is retried. We do this in dns_session_create() when we know that the applet was created in the release callback (when previous query attempt was unsuccessful), which means initial connection is not affected. [1]: https://www.mail-archive.com/haproxy@formilux.org/msg45665.html This should fix GH #2909 and may be backported to all stable versions. This patch depends on ("MINOR: applet: add appctx_schedule() macro")
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.