DOC: configuration: update maxconn description
Let's update maxconn keyword description, in order to make it clear, which
setting has the precedence over the global.maxconn and the SYSTEM_MAXCONN if
set.
(cherry picked from commit ff024206f0e0235551395c496e1aa7f23b74bf56)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit 72abbbb78491924f3c20715b606595d81a3a2deb)
Signed-off-by: Willy Tarreau <w@1wt.eu>
(cherry picked from commit e4e85d427ea001e942f8e7d42b0dae9ffbdf3e9b)
Signed-off-by: Willy Tarreau <w@1wt.eu>
diff --git a/doc/configuration.txt b/doc/configuration.txt
index 8b69cf9..abb620c 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -2713,18 +2713,25 @@
maxconn <number>
Sets the maximum per-process number of concurrent connections to <number>. It
- is equivalent to the command-line argument "-n". Proxies will stop accepting
- connections when this limit is reached. The "ulimit-n" parameter is
- automatically adjusted according to this value. See also "ulimit-n". Note:
- the "select" poller cannot reliably use more than 1024 file descriptors on
- some platforms. If your platform only supports select and reports "select
- FAILED" on startup, you need to reduce maxconn until it works (slightly
- below 500 in general). If this value is not set, it will automatically be
- calculated based on the current file descriptors limit reported by the
- "ulimit -n" command, possibly reduced to a lower value if a memory limit
- is enforced, based on the buffer size, memory allocated to compression, SSL
- cache size, and use or not of SSL and the associated maxsslconn (which can
- also be automatic). In any case, the fd-hard-limit applies if set.
+ is equivalent to the command-line argument "-n". The value provided in
+ command-line argument via "-n" takes the precedence over the maxconn value set
+ in the global section. Haproxy process could be also compiled with
+ SYSTEM_MAXCONN compile-time variable, which is served in this case as the
+ system maxconn maximum. Again, the command-line "-n" argument allows at
+ runtime to bypass SYSTEM_MAXCONN limit, if set. Proxies will stop accepting
+ connections when maxconn is reached. The process soft file descriptor limit
+ (could be obtained with "ulimit -n" command) is automatically adjusted
+ according to provided maxconn. See also "ulimit-n". Note: the "select" poller
+ cannot reliably use more than 1024 file descriptors on some platforms. If your
+ platform only supports select and reports "select FAILED" on startup, you need
+ to reduce the maxconn until it works (slightly below 500 in general). If
+ maxconn value is not set, it will be automatically calculated based on the
+ current file descriptors limits, reported by the "ulimit -nH" command (we take
+ the maximum between the hard and soft values), then automatic value will be
+ possibly reduced by "fd-hard-limit" and by memory limit, if the latter was
+ enforced via "-m" command line option. Automatic value is also dependent from
+ the buffer size, memory allocated to compression, SSL cache size, and the use
+ or not of SSL and the associated maxsslconn (which can also be automatic).
See also: fd-hard-limit, ulimit-n