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| author |   Marcelo Ricardo Leitner <mleitner@redhat.com> | 2015-02-23 15:02:34 -0300 |
|---|---|---|
| committer |   Simon Horman <horms@verge.net.au> | 2015-02-25 13:46:35 +0900 |
| commit | d752c364571743d696c2a54a449ce77550c35ac5 (patch) | |
| tree | 160b607482c080c720f27626fa7a7130307cbbf3 /Documentation | |
| parent | netfilter: ipset: fix boolreturn.cocci warnings (diff) | |
| download | linux-dev-d752c364571743d696c2a54a449ce77550c35ac5.tar.xz linux-dev-d752c364571743d696c2a54a449ce77550c35ac5.zip | |
ipvs: allow rescheduling of new connections when port reuse is detected
Currently, when TCP/SCTP port reusing happens, IPVS will find the old
entry and use it for the new one, behaving like a forced persistence.
But if you consider a cluster with a heavy load of small connections,
such reuse will happen often and may lead to a not optimal load
balancing and might prevent a new node from getting a fair load.
This patch introduces a new sysctl, conn_reuse_mode, that allows
controlling how to proceed when port reuse is detected. The default
value will allow rescheduling of new connections only if the old entry
was in TIME_WAIT state for TCP or CLOSED for SCTP.
Signed-off-by: Marcelo Ricardo Leitner <mleitner@redhat.com>
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/networking/ipvs-sysctl.txt | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/Documentation/networking/ipvs-sysctl.txt b/Documentation/networking/ipvs-sysctl.txt index 7a3c04729591..3ba709531adb 100644 --- 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 |