BUG/MINOR: listener: stop unbound listeners on startup
When a listener is not bound to a process its frontend belongs to, it
is only paused and not stopped. This creates confusion from the outside
as "netstat -ltnp" for example will report only the parent process as
the listener instead of the effective one. "ss -lnp" will report that
all processes are listening to all sockets.
This is confusing enough to suggest a fix. Now we simply stop the unused
listeners. Example with this simple config :
global
nbproc 4
frontend haproxy_test
bind-process 1-40
bind :12345 process 1
bind :12345 process 2
bind :12345 process 3
bind :12345 process 4
Before the patch :
$ netstat -ltnp
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:12345 0.0.0.0:* LISTEN 30457/./haproxy
tcp 0 0 0.0.0.0:12345 0.0.0.0:* LISTEN 30457/./haproxy
tcp 0 0 0.0.0.0:12345 0.0.0.0:* LISTEN 30457/./haproxy
tcp 0 0 0.0.0.0:12345 0.0.0.0:* LISTEN 30457/./haproxy
After the patch :
$ netstat -ltnp
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:12345 0.0.0.0:* LISTEN 30504/./haproxy
tcp 0 0 0.0.0.0:12345 0.0.0.0:* LISTEN 30503/./haproxy
tcp 0 0 0.0.0.0:12345 0.0.0.0:* LISTEN 30502/./haproxy
tcp 0 0 0.0.0.0:12345 0.0.0.0:* LISTEN 30501/./haproxy
This patch may be backported to 1.6 and 1.5, but it relies on commit
7a798e5 ("CLEANUP: fix inconsistency between fd->iocb, proto->accept
and accept()") since it will expose an API inconsistency by including
listener.h in the .c.
diff --git a/src/listener.c b/src/listener.c
index 566b340..59385f0 100644
--- a/src/listener.c
+++ b/src/listener.c
@@ -57,8 +57,7 @@
/* we don't want to enable this listener and don't
* want any fd event to reach it.
*/
- fd_stop_recv(listener->fd);
- listener->state = LI_PAUSED;
+ unbind_listener(listener);
}
else if (listener->nbconn < listener->maxconn) {
fd_want_recv(listener->fd);