c6221db375
In pcli_prefix_to_pid(), when resolving a worker by absolute pid (@!<pid>) or by relative pid (@1), a worker that still has PROC_O_INIT set (i.e. not yet ready, still initializing) could be returned as a valid target. During a reload, if a client connects to the master CLI and sends a command targeting a worker (e.g. @@1 or @@!<pid>), the master resolves the target pid and attempts to forward the command by transferring a fd over the worker's sockpair. If the worker is still initializing and has not yet sent its READY signal, its end of the sockpair is not usable, causing send_fd_uxst() to fail with EPIPE. This results in the following alert being repeated in a loop: [ALERT] (550032) : socketpair: Cannot transfer the fd 13 over sockpair@5. Giving up. The situation is even worse if the initializing worker has already exited (e.g. due to a bind failure) but has not yet been removed from the process list: in that case the sockpair's remote end is already closed, making the failure immediate and unrecoverable until the dead worker is cleaned up. This was not possible before 3.1 because the master's polling loop only started once all workers were fully ready, making it impossible to receive CLI connections while a worker was still initializing. Fix this by skipping workers with PROC_O_INIT set in both the absolute and relative pid resolution paths of pcli_prefix_to_pid(), so that only fully initialized workers can be targeted. Must be backported to 3.1 and later.
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.