mirror of
http://git.haproxy.org/git/haproxy.git
synced 2026-02-15 09:02:00 +02:00
de3c326389
this patch is a breaking change between v2.3 and v2.4: we move from using gauge value for health check states to labels values. The diff is quite small thanks to the preparation work from Christopher to allow more flexibility in labels, see commit5a2f938732("MEDIUM: contrib/prometheus-exporter: Use dynamic labels instead of static ones") this is a follow up of commitc6464591a3("MAJOR: contrib/prometheus-exporter: move ftd/bkd/srv states to labels"). The main goal being to be better aligned with prometheus use cases in terms of queries. More specifically to health checks, Pierre C. mentioned the possible quirks he had to put in place in order to make use of those metrics through prometheus: <aggregator_function> by(proxy, check_status) (count_values by(proxy, instance) ("check_status", haproxy_server_check_status)) I am perfectly aware this introduces a lot more metrics but I don't see how we can improve the usability without it. The main issue remains in the cardinality of the states which are > 20. Prometheus recommends to stay below a cardinality of 10 for a given metric but I consider our case very specific, because highly linked to the level of precision haproxy exposes. Even before this patch I saw several large production setup (a few hundreds of MB in output) which are making use of the scope parameter to simply ignore the server metrics, so that the scrapping can be faster, and memory consumed on client side not too high. So I believe we should eventually continue in that direction and offer more granularity of filtering of the output. That being said it is already possible to filter out the data on prometheus client side. this is related to github issue #1029 Signed-off-by: William Dauchy <wdauchy@gmail.com>
The HAProxy documentation has been split into a number of different files for ease of use. 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)