ipvs: allow rescheduling of new connections when port reuse is detected

[cascardo/linux.git] / Documentation / networking / ipvs-sysctl.txt

diff --git a/Documentation/networking/ipvs-sysctl.txt b/Documentation/networking/ipvs-sysctl.txt
index 7a3c047..3ba7095 100644 (file)
--- a/Documentation/networking/ipvs-sysctl.txt
+++ b/Documentation/networking/ipvs-sysctl.txt
@@ -22,6 +22,27 @@ backup_only - BOOLEAN
        If set, disable the director function while the server is
        in backup mode to avoid packet loops for DR/TUN methods.
 
+conn_reuse_mode - INTEGER
+       1 - default
+
+       Controls how ipvs will deal with connections that are detected
+       port reuse. It is a bitmap, with the values being:
+
+       0: disable any special handling on port reuse. The new
+       connection will be delivered to the same real server that was
+       servicing the previous connection. This will effectively
+       disable expire_nodest_conn.
+
+       bit 1: enable rescheduling of new connections when it is safe.
+       That is, whenever expire_nodest_conn and for TCP sockets, when
+       the connection is in TIME_WAIT state (which is only possible if
+       you use NAT mode).
+
+       bit 2: it is bit 1 plus, for TCP connections, when connections
+       are in FIN_WAIT state, as this is the last state seen by load
+       balancer in Direct Routing mode. This bit helps on adding new
+       real servers to a very busy cluster.
+
 conntrack - BOOLEAN
        0 - disabled (default)
        not 0 - enabled