Commit 5bd3834a authored by Thomas Klausner's avatar Thomas Klausner

Add extension to randomly choose one of the highest-scored hosts,

by increasing their score by one.
parent 6ebe55c0
......@@ -67,12 +67,13 @@ FD_EXTENSION_SUBDIR(app_redirect "Diameter Redirect server: send configurable Re
####
# Routing extensions
FD_EXTENSION_SUBDIR(rt_default "Configurable routing rules for freeDiameter" ON)
FD_EXTENSION_SUBDIR(rt_redirect "Handling of Diameter Redirect messages" ON)
FD_EXTENSION_SUBDIR(rt_busypeers "Handling of Diameter TOO_BUSY messages and relay timeouts" ON)
FD_EXTENSION_SUBDIR(rt_default "Configurable routing rules for freeDiameter" ON)
FD_EXTENSION_SUBDIR(rt_ereg "Configurable routing based on regexp matching of AVP values" OFF)
FD_EXTENSION_SUBDIR(rt_ignore_dh "Stow Destination-Host in Proxy-Info, restore to Origin-Host for answers" ON)
FD_EXTENSION_SUBDIR(rt_load_balance "Balance load over multiple equal hosts, based on outstanding requests" ON)
FD_EXTENSION_SUBDIR(rt_randomize "Randomly choose one of the highest scored hosts and increase its score by one" ON)
FD_EXTENSION_SUBDIR(rt_redirect "Handling of Diameter Redirect messages" ON)
####
......
# The rt_randomize extension
PROJECT("Routing extension randomly increases the routing count for one of the highest-rated hosts, if there are multiple ones" C)
# List of source files
SET(RT_RANDOMIZE_SRC
rt_randomize.c
)
INCLUDE_DIRECTORIES(${CMAKE_CURRENT_BINARY_DIR})
# Compile these files as a freeDiameter extension
FD_ADD_EXTENSION(rt_randomize ${RT_RANDOMIZE_SRC})
####
## INSTALL section ##
# We install with the daemon component because it is a base feature.
INSTALL(TARGETS rt_randomize
LIBRARY DESTINATION ${INSTALL_EXTENSIONS_SUFFIX}
COMPONENT freeDiameter-daemon)
/*********************************************************************************************************
* Software License Agreement (BSD License) *
* Author: Thomas Klausner <tk@giga.or.at> *
* *
* Copyright (c) 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>
/*
* Load balancing extension. If there are multiple highest-rated hosts with the same score,
* randomly increase the score of one of them.
*/
#include <stdlib.h>
static int seed;
static int rt_randomizing(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 there is more than one with positive score, randomly increase one of their scores by one */
if (max_score >= 0 && max_score_count > 1) {
int lucky_candidate = rand_r(&seed) % max_score_count;
int i = 0;
for (lic = candidates->next; lic != candidates; lic = lic->next) {
struct rtd_candidate * cand = (struct rtd_candidate *) lic;
if (cand->score == max_score) {
if (i == lucky_candidate) {
cand->score++;
break;
}
i++;
}
}
}
return 0;
}
/* handler */
static struct fd_rt_out_hdl * rt_randomizing_hdl = NULL;
/* entry point */
static int rt_randomize_entry(char * conffile)
{
/* Register the callback */
CHECK_FCT(fd_rt_out_register(rt_randomizing, NULL, 4, &rt_randomizing_hdl));
seed = (int)time(NULL);
TRACE_DEBUG(INFO, "Extension 'Randomizing' initialized");
return 0;
}
/* Unload */
void fd_ext_fini(void)
{
/* Unregister the callbacks */
CHECK_FCT_DO(fd_rt_out_unregister(rt_randomizing_hdl, NULL), /* continue */);
return ;
}
EXTENSION_ENTRY("rt_randomize", rt_randomize_entry);
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