Raducu Deaconu | eefa32d | 2015-07-17 08:45:40 +0300 | [diff] [blame] | 1 | /* |
| 2 | * IPVS: Overflow-Connection Scheduling module |
| 3 | * |
| 4 | * Authors: Raducu Deaconu <rhadoo_io@yahoo.com> |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU General Public License |
| 8 | * as published by the Free Software Foundation; either version |
| 9 | * 2 of the License, or (at your option) any later version. |
| 10 | * |
| 11 | * Scheduler implements "overflow" loadbalancing according to number of active |
| 12 | * connections , will keep all conections to the node with the highest weight |
| 13 | * and overflow to the next node if the number of connections exceeds the node's |
| 14 | * weight. |
| 15 | * Note that this scheduler might not be suitable for UDP because it only uses |
| 16 | * active connections |
| 17 | * |
| 18 | */ |
| 19 | |
| 20 | #define KMSG_COMPONENT "IPVS" |
| 21 | #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt |
| 22 | |
| 23 | #include <linux/module.h> |
| 24 | #include <linux/kernel.h> |
| 25 | |
| 26 | #include <net/ip_vs.h> |
| 27 | |
| 28 | /* OVF Connection scheduling */ |
| 29 | static struct ip_vs_dest * |
| 30 | ip_vs_ovf_schedule(struct ip_vs_service *svc, const struct sk_buff *skb, |
| 31 | struct ip_vs_iphdr *iph) |
| 32 | { |
| 33 | struct ip_vs_dest *dest, *h = NULL; |
| 34 | int hw = 0, w; |
| 35 | |
| 36 | IP_VS_DBG(6, "ip_vs_ovf_schedule(): Scheduling...\n"); |
| 37 | /* select the node with highest weight, go to next in line if active |
| 38 | * connections exceed weight |
| 39 | */ |
| 40 | list_for_each_entry_rcu(dest, &svc->destinations, n_list) { |
| 41 | w = atomic_read(&dest->weight); |
| 42 | if ((dest->flags & IP_VS_DEST_F_OVERLOAD) || |
| 43 | atomic_read(&dest->activeconns) > w || |
| 44 | w == 0) |
| 45 | continue; |
| 46 | if (!h || w > hw) { |
| 47 | h = dest; |
| 48 | hw = w; |
| 49 | } |
| 50 | } |
| 51 | |
| 52 | if (h) { |
| 53 | IP_VS_DBG_BUF(6, "OVF: server %s:%u active %d w %d\n", |
| 54 | IP_VS_DBG_ADDR(h->af, &h->addr), |
| 55 | ntohs(h->port), |
| 56 | atomic_read(&h->activeconns), |
| 57 | atomic_read(&h->weight)); |
| 58 | return h; |
| 59 | } |
| 60 | |
| 61 | ip_vs_scheduler_err(svc, "no destination available"); |
| 62 | return NULL; |
| 63 | } |
| 64 | |
| 65 | static struct ip_vs_scheduler ip_vs_ovf_scheduler = { |
| 66 | .name = "ovf", |
| 67 | .refcnt = ATOMIC_INIT(0), |
| 68 | .module = THIS_MODULE, |
| 69 | .n_list = LIST_HEAD_INIT(ip_vs_ovf_scheduler.n_list), |
| 70 | .schedule = ip_vs_ovf_schedule, |
| 71 | }; |
| 72 | |
| 73 | static int __init ip_vs_ovf_init(void) |
| 74 | { |
| 75 | return register_ip_vs_scheduler(&ip_vs_ovf_scheduler); |
| 76 | } |
| 77 | |
| 78 | static void __exit ip_vs_ovf_cleanup(void) |
| 79 | { |
| 80 | unregister_ip_vs_scheduler(&ip_vs_ovf_scheduler); |
| 81 | synchronize_rcu(); |
| 82 | } |
| 83 | |
| 84 | module_init(ip_vs_ovf_init); |
| 85 | module_exit(ip_vs_ovf_cleanup); |
| 86 | MODULE_LICENSE("GPL"); |