-/* $Id: filter_load_balance.cpp,v 1.1 2007-01-02 15:35:36 marc Exp $
- Copyright (c) 2005-2006, Index Data.
+/* This file is part of Metaproxy.
+ Copyright (C) 2005-2008 Index Data
- See the LICENSE file for details
- */
+Metaproxy 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, or (at your option) any later
+version.
+
+Metaproxy is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+*/
#include "config.hpp"
+#include "session.hpp"
+#include "package.hpp"
#include "filter.hpp"
#include "filter_load_balance.hpp"
-#include "package.hpp"
#include "util.hpp"
+
#include <boost/thread/mutex.hpp>
-#include <boost/date_time/posix_time/posix_time.hpp>
#include <yaz/zgdu.h>
-#include <iostream>
+// remove max macro if already defined (defined later in <limits>)
+#ifdef max
+#undef max
+#endif
+
+//#include <iostream>
+#include <list>
+#include <map>
+#include <limits>
namespace mp = metaproxy_1;
namespace yf = mp::filter;
void process(metaproxy_1::Package & package);
void configure(const xmlNode * ptr);
private:
+ // statistic manipulating functions,
+ void add_dead(unsigned long session_id);
+ //void clear_dead(unsigned long session_id);
+ void add_package(unsigned long session_id);
+ void remove_package(unsigned long session_id);
+ void add_session(unsigned long session_id, std::string target);
+ void remove_session(unsigned long session_id);
+ std::string find_session_target(unsigned long session_id);
+
+ // cost functions
+ unsigned int cost(std::string target);
+ unsigned int dead(std::string target);
+
+ // local classes
+ class TargetStat {
+ public:
+ unsigned int sessions;
+ unsigned int packages;
+ unsigned int deads;
+ unsigned int cost() {
+ unsigned int c = sessions + packages + deads;
+ //std::cout << "stats c:" << c
+ // << " s:" << sessions
+ // << " p:" << packages
+ // << " d:" << deads
+ // <<"\n";
+ return c;
+ }
+ };
+
+ // local protected databases
boost::mutex m_mutex;
+ std::map<std::string, TargetStat> m_target_stat;
+ std::map<unsigned long, std::string> m_session_target;
};
}
}
{ // must have a destructor because of boost::scoped_ptr
}
-void yf::LoadBalance::configure(const xmlNode *xmlnode)
+void yf::LoadBalance::configure(const xmlNode *xmlnode, bool test_only)
{
m_p->configure(xmlnode);
}
void yf::LoadBalance::Impl::process(mp::Package &package)
{
- Z_GDU *gdu_req = package.request().get();
+ bool is_closed_front = false;
+ bool is_closed_back = false;
- // passing anything but z3950 packages
- if (!gdu_req
- || !(gdu_req->which == Z_GDU_Z3950))
- {
- package.move();
- return;
- }
-
+ // checking for closed front end packages
+ if (package.session().is_closed()){
+ is_closed_front = true;
+ }
- // target selecting only on Z39.50 init request
- if (gdu_req->u.z3950->which == Z_APDU_initRequest){
+ Z_GDU *gdu_req = package.request().get();
- mp::odr odr_en(ODR_ENCODE);
- Z_InitRequest *org_init = gdu_req->u.z3950->u.initRequest;
+ // passing anything but z3950 packages
+ if (gdu_req && gdu_req->which == Z_GDU_Z3950){
- // extracting virtual hosts
- std::list<std::string> vhosts;
+ // target selecting only on Z39.50 init request
+ if (gdu_req->u.z3950->which == Z_APDU_initRequest){
- mp::util::remove_vhost_otherinfo(&(org_init->otherInfo), vhosts);
+ mp::odr odr_en(ODR_ENCODE);
+ Z_InitRequest *org_init = gdu_req->u.z3950->u.initRequest;
- //std::cout << "LoadBalance::Impl::process() vhosts: "
- // << vhosts.size() << "\n";
- //std::cout << "LoadBalance::Impl::process()" << *gdu_req << "\n";
-
- // choosing one target according to load-balancing algorithm
-
- if (vhosts.size()){
- std::string target;
+ // extracting virtual hosts
+ std::list<std::string> vhosts;
- // getting timestamp for receiving of package
- boost::posix_time::ptime receive_time
- = boost::posix_time::microsec_clock::local_time();
+ mp::util::remove_vhost_otherinfo(&(org_init->otherInfo), vhosts);
- // //<< receive_time << " "
- // //<< to_iso_string(receive_time) << " "
- //<< to_iso_extended_string(receive_time) << " "
- // package.session().id();
-
- { // scope for locking local target database
- boost::mutex::scoped_lock scoped_lock(m_mutex);
- target = *vhosts.begin();
- }
+ // choosing one target according to load-balancing algorithm
+ if (vhosts.size()){
+ std::string target;
+ unsigned int cost = std::numeric_limits<unsigned int>::max();
+
+ { //locking scope for local databases
+ boost::mutex::scoped_lock scoped_lock(m_mutex);
+
+ // load-balancing algorithm goes here
+ //target = *vhosts.begin();
+ for(std::list<std::string>::const_iterator ivh
+ = vhosts.begin();
+ ivh != vhosts.end();
+ ivh++){
+ if ((*ivh).size() != 0){
+ unsigned int vhcost
+ = yf::LoadBalance::Impl::cost(*ivh);
+ if (cost > vhcost){
+ cost = vhcost;
+ target = *ivh;
+ }
+ }
+ }
+
+ // updating local database
+ add_session(package.session().id(), target);
+ yf::LoadBalance::Impl::cost(target);
+ add_package(package.session().id());
+ }
+
+ // copying new target into init package
+ mp::util::set_vhost_otherinfo(&(org_init->otherInfo),
+ odr_en, target, 1);
+ package.request() = gdu_req;
+ }
- // copying new target into init package
- mp::util::set_vhost_otherinfo(&(org_init->otherInfo), odr_en, target);
- package.request() = gdu_req;
}
-
+ // frontend Z39.50 close request is added to statistics and marked
+ else if (gdu_req->u.z3950->which == Z_APDU_close){
+ is_closed_front = true;
+ boost::mutex::scoped_lock scoped_lock(m_mutex);
+ add_package(package.session().id());
+ }
+ // any other Z39.50 package is added to statistics
+ else {
+ boost::mutex::scoped_lock scoped_lock(m_mutex);
+ add_package(package.session().id());
+ }
}
-
- // moving all Z39.50 package typess
+ // moving all package types
package.move();
-
- //boost::posix_time::ptime send_time
- // = boost::posix_time::microsec_clock::local_time();
+ // checking for closed back end packages
+ if (package.session().is_closed())
+ is_closed_back = true;
+
+ Z_GDU *gdu_res = package.response().get();
+
+ // passing anything but z3950 packages
+ if (gdu_res && gdu_res->which == Z_GDU_Z3950){
+
+ // session closing only on Z39.50 close response
+ if (gdu_res->u.z3950->which == Z_APDU_close){
+ is_closed_back = true;
+ boost::mutex::scoped_lock scoped_lock(m_mutex);
+ remove_package(package.session().id());
+ }
+ // any other Z39.50 package is removed from statistics
+ else {
+ boost::mutex::scoped_lock scoped_lock(m_mutex);
+ remove_package(package.session().id());
+ }
+ }
+
+ // finally removing sessions and marking deads
+ if (is_closed_back || is_closed_front){
+ boost::mutex::scoped_lock scoped_lock(m_mutex);
+
+ // marking backend dead if backend closed without fronted close
+ if (is_closed_front == false)
+ add_dead(package.session().id());
+
+ remove_session(package.session().id());
+
+ // making sure that package is closed
+ package.session().close();
+ }
+}
+
+// statistic manipulating functions,
+void yf::LoadBalance::Impl::add_dead(unsigned long session_id){
+
+
+ std::string target = find_session_target(session_id);
+
+ if (target.size() != 0){
+ std::map<std::string, TargetStat>::iterator itarg;
+ itarg = m_target_stat.find(target);
+ if (itarg != m_target_stat.end()
+ && itarg->second.deads < std::numeric_limits<unsigned int>::max()){
+ itarg->second.deads += 1;
+ // std:.cout << "add_dead " << session_id << " " << target
+ // << " d:" << itarg->second.deads << "\n";
+ }
+ }
+};
+
+//void yf::LoadBalance::Impl::clear_dead(unsigned long session_id){
+// std::cout << "clear_dead " << session_id << "\n";
+//};
+
+void yf::LoadBalance::Impl::add_package(unsigned long session_id){
+
+ std::string target = find_session_target(session_id);
+
+ if (target.size() != 0){
+ std::map<std::string, TargetStat>::iterator itarg;
+ itarg = m_target_stat.find(target);
+ if (itarg != m_target_stat.end()
+ && itarg->second.packages
+ < std::numeric_limits<unsigned int>::max()){
+ itarg->second.packages += 1;
+ // std:.cout << "add_package " << session_id << " " << target
+ // << " p:" << itarg->second.packages << "\n";
+ }
+ }
+};
+
+void yf::LoadBalance::Impl::remove_package(unsigned long session_id){
+ std::string target = find_session_target(session_id);
+
+ if (target.size() != 0){
+ std::map<std::string, TargetStat>::iterator itarg;
+ itarg = m_target_stat.find(target);
+ if (itarg != m_target_stat.end()
+ && itarg->second.packages > 0){
+ itarg->second.packages -= 1;
+ // std:.cout << "remove_package " << session_id << " " << target
+ // << " p:" << itarg->second.packages << "\n";
+ }
+ }
+};
- //boost::posix_time::time_duration duration = send_time - receive_time;
+void yf::LoadBalance::Impl::add_session(unsigned long session_id,
+ std::string target){
+ // finding and adding session
+ std::map<unsigned long, std::string>::iterator isess;
+ isess = m_session_target.find(session_id);
+ if (isess == m_session_target.end()){
+ m_session_target.insert(std::make_pair(session_id, target));
+ }
+
+ // finding and adding target statistics
+ std::map<std::string, TargetStat>::iterator itarg;
+ itarg = m_target_stat.find(target);
+ if (itarg == m_target_stat.end()){
+ TargetStat stat;
+ stat.sessions = 1;
+ stat.packages = 0; // no idea why the defaut constructor TargetStat()
+ stat.deads = 0; // is not initializig this correctly to zero ??
+ m_target_stat.insert(std::make_pair(target, stat));
+ // std:.cout << "add_session " << session_id << " " << target
+ // << " s:1\n";
+ }
+ else if (itarg->second.sessions < std::numeric_limits<unsigned int>::max())
+ {
+ itarg->second.sessions += 1;
+ // std:.cout << "add_session " << session_id << " " << target
+ // << " s:" << itarg->second.sessions << "\n";
+ }
+};
+
+void yf::LoadBalance::Impl::remove_session(unsigned long session_id){
+
+ std::string target;
+
+ // finding session
+ std::map<unsigned long, std::string>::iterator isess;
+ isess = m_session_target.find(session_id);
+ if (isess == m_session_target.end())
+ return;
+ else
+ target = isess->second;
+
+ // finding target statistics
+ std::map<std::string, TargetStat>::iterator itarg;
+ itarg = m_target_stat.find(target);
+ if (itarg == m_target_stat.end()){
+ m_session_target.erase(isess);
+ return;
+ }
+
+ // counting session down
+ if (itarg->second.sessions > 0)
+ itarg->second.sessions -= 1;
- // { // scope for locking local target database
- // boost::mutex::scoped_lock scoped_lock(m_mutex);
- // target = *vhosts.begin();
- // }
+ // std:.cout << "remove_session " << session_id << " " << target
+ // << " s:" << itarg->second.sessions << "\n";
+
+ // clearing empty sessions and targets
+ if (itarg->second.sessions == 0 && itarg->second.deads == 0 ){
+ m_target_stat.erase(itarg);
+ m_session_target.erase(isess);
+ }
+};
+std::string
+yf::LoadBalance::Impl::find_session_target(unsigned long session_id){
+ std::string target;
+ std::map<unsigned long, std::string>::iterator isess;
+ isess = m_session_target.find(session_id);
+ if (isess != m_session_target.end())
+ target = isess->second;
+ return target;
}
+// cost functions
+unsigned int yf::LoadBalance::Impl::cost(std::string target){
+
+ unsigned int cost;
+
+ if (target.size() != 0){
+ std::map<std::string, TargetStat>::iterator itarg;
+ itarg = m_target_stat.find(target);
+ if (itarg != m_target_stat.end()){
+ cost = itarg->second.cost();
+ }
+ }
+
+ //std::cout << "cost " << target << " c:" << cost << "\n";
+ return cost;
+};
+
+unsigned int yf::LoadBalance::Impl::dead(std::string target){
+
+ unsigned int dead;
+
+ if (target.size() != 0){
+ std::map<std::string, TargetStat>::iterator itarg;
+ itarg = m_target_stat.find(target);
+ if (itarg != m_target_stat.end()){
+ dead = itarg->second.deads;
+ }
+ }
+
+ //std::cout << "dead " << target << " d:" << dead << "\n";
+ return dead;
+};
+
+
+
+
static mp::filter::Base* filter_creator()
{
return new mp::filter::LoadBalance;
/*
* Local variables:
* c-basic-offset: 4
+ * c-file-style: "Stroustrup"
* indent-tabs-mode: nil
- * c-file-style: "stroustrup"
* End:
* vim: shiftwidth=4 tabstop=8 expandtab
*/
+
projects / metaproxy-moved-to-github.git / blobdiff