From 616a9be25cb9516e546c0de55d61e1e46e54ade9 Mon Sep 17 00:00:00 2001 From: Kenny Mathis Date: Tue, 9 Sep 2014 09:20:15 -0400 Subject: [PATCH] ipvs: Add simple weighted failover scheduler 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 Acked-by: Julian Anastasov Signed-off-by: Simon Horman --- 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 + * + * 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 +#include + +#include + +/* 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"); -- 2.7.4