MEDIUM: make SO_REUSEPORT configurable
With Linux officially introducing SO_REUSEPORT support in 3.9 and
its mainstream adoption we have seen more people running into strange
SO_REUSEPORT related issues (a process management issue turning into
hard to diagnose problems because the kernel load-balances between the
new and an obsolete haproxy instance).
Also some people simply want the guarantee that the bind fails when
the old process is still bound.
This change makes SO_REUSEPORT configurable, introducing the command
line argument "-dR" and the noreuseport configuration directive.
A backport to 1.6 should be considered.
diff --git a/src/proto_tcp.c b/src/proto_tcp.c
index b614e6b..91d6688 100644
--- a/src/proto_tcp.c
+++ b/src/proto_tcp.c
@@ -823,10 +823,10 @@
setsockopt(fd, SOL_SOCKET, SO_LINGER, &nolinger, sizeof(struct linger));
#ifdef SO_REUSEPORT
- /* OpenBSD supports this. As it's present in old libc versions of Linux,
- * it might return an error that we will silently ignore.
+ /* OpenBSD and Linux 3.9 support this. As it's present in old libc versions of
+ * Linux, it might return an error that we will silently ignore.
*/
- if (!ext)
+ if (!ext && (global.tune.options & GTUNE_USE_REUSEPORT))
setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &one, sizeof(one));
#endif