Mercurial > hg > freeDiameter
view extensions/rt_load_balance/rt_load_balance.c @ 1562:6219359a36a9 default tip
Merge latest changes from proposed branch
author | Sebastien Decugis <sdecugis@freediameter.net> |
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date | Mon, 21 Jun 2021 19:08:18 +0800 |
parents | 1a9c73262a88 |
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/********************************************************************************************************* * Software License Agreement (BSD License) * * Author: Thomas Klausner <tk@giga.or.at> * * * * Copyright (c) 2013, 2014 Thomas Klausner * * All rights reserved. * * * * Written under contract by nfotex IT GmbH, http://nfotex.com/ * * * * Redistribution and use of this software in source and binary forms, with or without modification, are * * permitted provided that the following conditions are met: * * * * * Redistributions of source code must retain the above * * copyright notice, this list of conditions and the * * following disclaimer. * * * * * Redistributions in binary form must reproduce the above * * copyright notice, this list of conditions and the * * following disclaimer in the documentation and/or other * * materials provided with the distribution. * * * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED * * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A * * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR * * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR * * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF * * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * *********************************************************************************************************/ #include <freeDiameter/extension.h> #include <limits.h> #include <time.h> struct best_candidate_entry { long load; struct rtd_candidate *cand; }; static unsigned int seed; #define MODULE_NAME "rt_load_balance" /* * Load balancing extension. Send request to least-loaded node: Add a * score of 1 to the least loaded candidates among those with highest * score. */ /* The callback for load balancing the requests across the peers */ static int rt_load_balancing(void * cbdata, struct msg ** pmsg, struct fd_list * candidates) { struct fd_list *lic; struct msg * msg = *pmsg; int max_score = -1; int max_score_count = 0; TRACE_ENTRY("%p %p %p", cbdata, msg, candidates); CHECK_PARAMS(msg && candidates); /* Check if it is worth processing the message */ if (FD_IS_LIST_EMPTY(candidates)) return 0; /* find out maximal score and how many candidates have it */ for (lic = candidates->next; lic != candidates; lic = lic->next) { struct rtd_candidate * cand = (struct rtd_candidate *) lic; if (max_score < cand->score) { max_score = cand->score; max_score_count = 1; } else if (cand->score == max_score) { max_score_count++; } } if (max_score_count > 0) { /* find out minimum load among those with maximal * score, and how many candidates have it */ struct best_candidate_entry best_candidates[max_score_count]; long min_load = LONG_MAX; int min_load_count = 0; int j; for (j = 0, lic = candidates->next; lic != candidates; lic = lic->next) { struct rtd_candidate * cand = (struct rtd_candidate *) lic; if (cand->score == max_score) { long to_receive, to_send, load; struct peer_hdr *peer; CHECK_FCT(fd_peer_getbyid(cand->diamid, cand->diamidlen, 0, &peer)); CHECK_FCT(fd_peer_get_load_pending(peer, &to_receive, &to_send)); load = to_receive + to_send; best_candidates[j].cand = cand; best_candidates[j].load = load; j++; if (min_load > load) { min_load = load; min_load_count = 1; } else if (min_load == load) { min_load_count++; } } } /* increase score by 1 for all entries with minimum * load, and further increase by 1 for one randomly * chosen candidate */ if (min_load_count > 0) { int lucky_candidate = rand_r(&seed) % min_load_count; int i; for (j = 0, i = 0; j < max_score_count; j++) { struct best_candidate_entry *entry = best_candidates+j; if (entry->load == min_load) { struct rtd_candidate *cand = entry->cand; int old_score = cand->score; cand->score++; TRACE_DEBUG(FULL, "%s: boosting peer `%.*s', score was %d, now %d; load was %ld", MODULE_NAME, (int)cand->diamidlen, cand->diamid, old_score, cand->score, entry->load); if (i == lucky_candidate) { cand->score++; TRACE_DEBUG(FULL, "%s: boosting lucky peer `%.*s', score was %d, now %d; load was %ld", MODULE_NAME, (int)cand->diamidlen, cand->diamid, old_score, cand->score, entry->load); } i++; } } } } return 0; } /* handler */ static struct fd_rt_out_hdl * rt_load_balancing_hdl = NULL; /* entry point */ static int rt_load_balance_entry(char * conffile) { /* Register the callback */ CHECK_FCT(fd_rt_out_register(rt_load_balancing, NULL, 10, &rt_load_balancing_hdl)); seed = (unsigned int)time(NULL); TRACE_DEBUG(INFO, "Extension 'Load Balancing' initialized"); return 0; } /* Unload */ void fd_ext_fini(void) { /* Unregister the callbacks */ CHECK_FCT_DO(fd_rt_out_unregister(rt_load_balancing_hdl, NULL), /* continue */); return ; } EXTENSION_ENTRY(MODULE_NAME, rt_load_balance_entry);