tree a776b2cfda996a03a9d715da934e732e4060803f
parent 3ac4f5dcf9a4420ffbcb307f7af390a6b764688f
author Valentine Krasnobaeva <vkrasnobaeva@haproxy.com> 1720025135 +0200
committer Willy Tarreau <w@1wt.eu> 1722257749 +0200
encoding latin1

MEDIUM: init: set default for fd_hard_limit via DEFAULT_MAXFD (take #2)

Let's provide a default value for fd_hard_limit, if it's not set in the
configuration. With this patch we could set some specific default via
compile-time variable DEFAULT_MAXFD as well. Hope, this will be helpfull for
haproxy package maintainers.

    make -j 8 TARGET=linux-glibc DEBUG=-DDEFAULT_MAXFD=50000

If haproxy is comipled without DEFAULT_MAXFD defined, the default will be set
to 1048576.

This is done to avoid killing the process by its watchdog, while it started
without any limitations in its configuration or in the command line and the
hard RLIMIT_NOFILE is extremely huge (~1000000000). We use in this case
compute_ideal_maxconn() to calculate maxconn and maxsock, maxsock defines the
size of internal fdtab, which becames very-very large as well. When
the process starts to simply loop over this fdtab (0(n)), this takes a lot of
time, so watchdog does it job.

To avoid this, maxconn now is always reduced to some reasonable value either
by explicit global.fd-hard-limit from configuration, or by its default. The
default may be changed at build-time and overwritten then by
global.fd-hard-limit at runtime. Explicit global.fd-hard-limit from the
configuration has always precedence over DEFAULT_MAXFD, if set.

Must be backported in all stable versions until v2.6.0, including v2.6.0.

(cherry picked from commit 41275a691839df5f8dc7cb9faa4e259fbb755d34)
[wt: the discussion around this patch came to an agreement on the list:
     https://www.mail-archive.com/haproxy@formilux.org/msg45098.html ]
Signed-off-by: Willy Tarreau <w@1wt.eu>
(cherry picked from commit d6c8f7d7ae18a52783febde97b91291e5e211c65)
Signed-off-by: Willy Tarreau <w@1wt.eu>
(cherry picked from commit 58ad85764e0c5e7f4bf5cf4f678cd7cb70d9454a)
Signed-off-by: Willy Tarreau <w@1wt.eu>