From: Kenny Mathis <kmathis@xxxxxxxxxxxxxx>
Add simple weighted IPVS failover support to the Linux kernel. All
other scheduling modules implement some form of load balancing, while
this offers a simple failover solution. Connections are directed to
the appropriate server based solely on highest weight value and server
availability. Tested functionality with keepalived.
Signed-off-by: Kenny Mathis <kmathis@xxxxxxxxxxxxxx>
Acked-by: Julian Anastasov <ja@xxxxxx>
Signed-off-by: Simon Horman <horms@xxxxxxxxxxxx>
---
net/netfilter/ipvs/Kconfig | 10 ++++++
net/netfilter/ipvs/Makefile | 1 +
net/netfilter/ipvs/ip_vs_fo.c | 79 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 90 insertions(+)
create mode 100644 net/netfilter/ipvs/ip_vs_fo.c
diff --git a/net/netfilter/ipvs/Kconfig b/net/netfilter/ipvs/Kconfig
index 0c3b167..3b6929d 100644
--- a/net/netfilter/ipvs/Kconfig
+++ b/net/netfilter/ipvs/Kconfig
@@ -152,6 +152,16 @@ config IP_VS_WLC
If you want to compile it in kernel, say Y. To compile it as a
module, choose M here. If unsure, say N.
+config IP_VS_FO
+ tristate "weighted failover scheduling"
+ ---help---
+ The weighted failover scheduling algorithm directs network
+ connections to the server with the highest weight that is
+ currently available.
+
+ If you want to compile it in kernel, say Y. To compile it as a
+ module, choose M here. If unsure, say N.
+
config IP_VS_LBLC
tristate "locality-based least-connection scheduling"
---help---
diff --git a/net/netfilter/ipvs/Makefile b/net/netfilter/ipvs/Makefile
index 34ee602..38b2723 100644
--- a/net/netfilter/ipvs/Makefile
+++ b/net/netfilter/ipvs/Makefile
@@ -26,6 +26,7 @@ obj-$(CONFIG_IP_VS_RR) += ip_vs_rr.o
obj-$(CONFIG_IP_VS_WRR) += ip_vs_wrr.o
obj-$(CONFIG_IP_VS_LC) += ip_vs_lc.o
obj-$(CONFIG_IP_VS_WLC) += ip_vs_wlc.o
+obj-$(CONFIG_IP_VS_FO) += ip_vs_fo.o
obj-$(CONFIG_IP_VS_LBLC) += ip_vs_lblc.o
obj-$(CONFIG_IP_VS_LBLCR) += ip_vs_lblcr.o
obj-$(CONFIG_IP_VS_DH) += ip_vs_dh.o
diff --git a/net/netfilter/ipvs/ip_vs_fo.c b/net/netfilter/ipvs/ip_vs_fo.c
new file mode 100644
index 0000000..6a2647d
--- /dev/null
+++ b/net/netfilter/ipvs/ip_vs_fo.c
@@ -0,0 +1,79 @@
+/*
+ * IPVS: Weighted Fail Over module
+ *
+ * Authors: Kenny Mathis <kmathis@xxxxxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * Changes:
+ * Kenny Mathis : added initial functionality based on weight
+ *
+ */
+
+#define KMSG_COMPONENT "IPVS"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+
+#include <net/ip_vs.h>
+
+/* Weighted Fail Over Module */
+static struct ip_vs_dest *
+ip_vs_fo_schedule(struct ip_vs_service *svc, const struct sk_buff *skb,
+ struct ip_vs_iphdr *iph)
+{
+ struct ip_vs_dest *dest, *hweight = NULL;
+ int hw = 0; /* Track highest weight */
+
+ IP_VS_DBG(6, "ip_vs_fo_schedule(): Scheduling...\n");
+
+ /* Basic failover functionality
+ * Find virtual server with highest weight and send it traffic
+ */
+ list_for_each_entry_rcu(dest, &svc->destinations, n_list) {
+ if (!(dest->flags & IP_VS_DEST_F_OVERLOAD) &&
+ atomic_read(&dest->weight) > hw) {
+ hweight = dest;
+ hw = atomic_read(&dest->weight);
+ }
+ }
+
+ if (hweight) {
+ IP_VS_DBG_BUF(6, "FO: server %s:%u activeconns %d weight %d\n",
+ IP_VS_DBG_ADDR(svc->af, &hweight->addr),
+ ntohs(hweight->port),
+ atomic_read(&hweight->activeconns),
+ atomic_read(&hweight->weight));
+ return hweight;
+ }
+
+ ip_vs_scheduler_err(svc, "no destination available");
+ return NULL;
+}
+
+static struct ip_vs_scheduler ip_vs_fo_scheduler = {
+ .name = "fo",
+ .refcnt = ATOMIC_INIT(0),
+ .module = THIS_MODULE,
+ .n_list = LIST_HEAD_INIT(ip_vs_fo_scheduler.n_list),
+ .schedule = ip_vs_fo_schedule,
+};
+
+static int __init ip_vs_fo_init(void)
+{
+ return register_ip_vs_scheduler(&ip_vs_fo_scheduler);
+}
+
+static void __exit ip_vs_fo_cleanup(void)
+{
+ unregister_ip_vs_scheduler(&ip_vs_fo_scheduler);
+ synchronize_rcu();
+}
+
+module_init(ip_vs_fo_init);
+module_exit(ip_vs_fo_cleanup);
+MODULE_LICENSE("GPL");
--
2.0.1
--
To unsubscribe from this list: send the line "unsubscribe lvs-devel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
