Files
linux/net/ipv4/ipvs/ip_vs_lc.c
Julius Volz e7ade46a53 IPVS: Change IPVS data structures to support IPv6 addresses
Introduce new 'af' fields into IPVS data structures for specifying an
entry's address family. Convert IP addresses to be of type union
nf_inet_addr.

Signed-off-by: Julius Volz <juliusv@google.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
2008-09-05 11:17:03 +10:00

101 lines
2.7 KiB
C

/*
* IPVS: Least-Connection Scheduling module
*
* Authors: Wensong Zhang <wensong@linuxvirtualserver.org>
*
* 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:
* Wensong Zhang : added the ip_vs_lc_update_svc
* Wensong Zhang : added any dest with weight=0 is quiesced
*
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <net/ip_vs.h>
static inline unsigned int
ip_vs_lc_dest_overhead(struct ip_vs_dest *dest)
{
/*
* We think the overhead of processing active connections is 256
* times higher than that of inactive connections in average. (This
* 256 times might not be accurate, we will change it later) We
* use the following formula to estimate the overhead now:
* dest->activeconns*256 + dest->inactconns
*/
return (atomic_read(&dest->activeconns) << 8) +
atomic_read(&dest->inactconns);
}
/*
* Least Connection scheduling
*/
static struct ip_vs_dest *
ip_vs_lc_schedule(struct ip_vs_service *svc, const struct sk_buff *skb)
{
struct ip_vs_dest *dest, *least = NULL;
unsigned int loh = 0, doh;
IP_VS_DBG(6, "ip_vs_lc_schedule(): Scheduling...\n");
/*
* Simply select the server with the least number of
* (activeconns<<5) + inactconns
* Except whose weight is equal to zero.
* If the weight is equal to zero, it means that the server is
* quiesced, the existing connections to the server still get
* served, but no new connection is assigned to the server.
*/
list_for_each_entry(dest, &svc->destinations, n_list) {
if ((dest->flags & IP_VS_DEST_F_OVERLOAD) ||
atomic_read(&dest->weight) == 0)
continue;
doh = ip_vs_lc_dest_overhead(dest);
if (!least || doh < loh) {
least = dest;
loh = doh;
}
}
if (least)
IP_VS_DBG(6, "LC: server %u.%u.%u.%u:%u activeconns %d inactconns %d\n",
NIPQUAD(least->addr.ip), ntohs(least->port),
atomic_read(&least->activeconns),
atomic_read(&least->inactconns));
return least;
}
static struct ip_vs_scheduler ip_vs_lc_scheduler = {
.name = "lc",
.refcnt = ATOMIC_INIT(0),
.module = THIS_MODULE,
.n_list = LIST_HEAD_INIT(ip_vs_lc_scheduler.n_list),
.schedule = ip_vs_lc_schedule,
};
static int __init ip_vs_lc_init(void)
{
return register_ip_vs_scheduler(&ip_vs_lc_scheduler) ;
}
static void __exit ip_vs_lc_cleanup(void)
{
unregister_ip_vs_scheduler(&ip_vs_lc_scheduler);
}
module_init(ip_vs_lc_init);
module_exit(ip_vs_lc_cleanup);
MODULE_LICENSE("GPL");