1 /* This file is part of Metaproxy.
2 Copyright (C) 2005-2011 Index Data
4 Metaproxy is free software; you can redistribute it and/or modify it under
5 the terms of the GNU General Public License as published by the Free
6 Software Foundation; either version 2, or (at your option) any later
9 Metaproxy is distributed in the hope that it will be useful, but WITHOUT ANY
10 WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
20 #include <metaproxy/package.hpp>
21 #include <metaproxy/filter.hpp>
22 #include "filter_load_balance.hpp"
23 #include <metaproxy/util.hpp>
26 #include <boost/thread/mutex.hpp>
28 #include <yaz/diagbib1.h>
32 // remove max macro if already defined (defined later in <limits>)
42 namespace mp = metaproxy_1;
43 namespace yf = mp::filter;
49 class LoadBalance::Impl
54 void process(metaproxy_1::Package & package);
55 void configure(const xmlNode * ptr);
57 // statistic manipulating functions,
58 void add_dead(unsigned long session_id);
59 //void clear_dead(unsigned long session_id);
60 void add_package(unsigned long session_id);
61 void remove_package(unsigned long session_id);
62 void add_session(unsigned long session_id, std::string target);
63 void remove_session(unsigned long session_id);
64 std::string find_session_target(unsigned long session_id);
67 unsigned int cost(std::string target);
68 unsigned int dead(std::string target);
73 unsigned int sessions;
74 unsigned int packages;
77 unsigned int c = sessions + packages + deads;
82 // local protected databases
84 std::map<std::string, TargetStat> m_target_stat;
85 std::map<unsigned long, std::string> m_session_target;
90 // define Pimpl wrapper forwarding to Impl
92 yf::LoadBalance::LoadBalance() : m_p(new Impl)
96 yf::LoadBalance::~LoadBalance()
97 { // must have a destructor because of boost::scoped_ptr
100 void yf::LoadBalance::configure(const xmlNode *xmlnode, bool test_only,
103 m_p->configure(xmlnode);
106 void yf::LoadBalance::process(mp::Package &package) const
108 m_p->process(package);
112 yf::LoadBalance::Impl::Impl()
116 yf::LoadBalance::Impl::~Impl()
120 void yf::LoadBalance::Impl::configure(const xmlNode *xmlnode)
124 void yf::LoadBalance::Impl::process(mp::Package &package)
126 bool is_closed_front = false;
128 // checking for closed front end packages
129 if (package.session().is_closed())
131 is_closed_front = true;
134 Z_GDU *gdu_req = package.request().get();
136 // passing anything but z3950 packages
137 if (gdu_req && gdu_req->which == Z_GDU_Z3950)
139 // target selecting only on Z39.50 init request
140 if (gdu_req->u.z3950->which == Z_APDU_initRequest)
142 yazpp_1::GDU base_req(gdu_req);
143 Z_APDU *apdu = base_req.get()->u.z3950;
145 Z_InitRequest *org_init = base_req.get()->u.z3950->u.initRequest;
146 mp::odr odr_en(ODR_ENCODE);
148 std::list<std::string> vhosts;
149 mp::util::remove_vhost_otherinfo(&(org_init->otherInfo), vhosts);
150 // get lowest of all vhosts.. Remove them if individually if
151 // they turn out to be bad..
155 std::list<std::string>::iterator ivh = vhosts.begin();
157 Package init_pkg(package.session(), package.origin());
158 init_pkg.copy_filter(package);
160 unsigned int cost = std::numeric_limits<unsigned int>::max();
162 boost::mutex::scoped_lock scoped_lock(m_mutex);
164 for (; ivh != vhosts.end(); )
166 if ((*ivh).size() != 0)
169 = yf::LoadBalance::Impl::cost(*ivh);
170 yaz_log(YLOG_LOG, "Consider %s cost=%u vhcost=%u",
171 (*ivh).c_str(), cost, vhcost);
176 ivh = vhosts.erase(ivh);
185 if (target.length() == 0)
187 // copying new target into init package
189 yazpp_1::GDU init_gdu(base_req);
190 Z_InitRequest *init_req = init_gdu.get()->u.z3950->u.initRequest;
192 mp::util::set_vhost_otherinfo(&(init_req->otherInfo),
195 init_pkg.request() = init_gdu;
197 // moving all package types
200 // checking for closed back end packages
201 if (!init_pkg.session().is_closed())
203 add_session(package.session().id(), target);
205 package.response() = init_pkg.response();
210 package.response() = odr.create_initResponse(
211 apdu, YAZ_BIB1_TEMPORARY_SYSTEM_ERROR,
212 "load_balance: no available targets");
213 package.session().close();
216 // frontend Z39.50 close request is added to statistics and marked
217 else if (gdu_req->u.z3950->which == Z_APDU_close)
219 is_closed_front = true;
220 boost::mutex::scoped_lock scoped_lock(m_mutex);
221 add_package(package.session().id());
223 // any other Z39.50 package is added to statistics
226 boost::mutex::scoped_lock scoped_lock(m_mutex);
227 add_package(package.session().id());
231 // moving all package types
234 bool is_closed_back = false;
236 // checking for closed back end packages
237 if (package.session().is_closed())
238 is_closed_back = true;
240 Z_GDU *gdu_res = package.response().get();
242 // passing anything but z3950 packages
243 if (gdu_res && gdu_res->which == Z_GDU_Z3950)
245 // session closing only on Z39.50 close response
246 if (gdu_res->u.z3950->which == Z_APDU_close)
248 is_closed_back = true;
249 boost::mutex::scoped_lock scoped_lock(m_mutex);
250 remove_package(package.session().id());
252 // any other Z39.50 package is removed from statistics
255 boost::mutex::scoped_lock scoped_lock(m_mutex);
256 remove_package(package.session().id());
260 // finally removing sessions and marking deads
261 if (is_closed_back || is_closed_front)
263 boost::mutex::scoped_lock scoped_lock(m_mutex);
265 // marking backend dead if backend closed without fronted close
266 if (is_closed_front == false)
267 add_dead(package.session().id());
269 remove_session(package.session().id());
271 // making sure that package is closed
272 package.session().close();
276 // statistic manipulating functions,
277 void yf::LoadBalance::Impl::add_dead(unsigned long session_id)
279 std::string target = find_session_target(session_id);
281 if (target.size() != 0)
283 std::map<std::string, TargetStat>::iterator itarg;
284 itarg = m_target_stat.find(target);
285 if (itarg != m_target_stat.end()
286 && itarg->second.deads < std::numeric_limits<unsigned int>::max())
288 itarg->second.deads += 1;
289 // std:.cout << "add_dead " << session_id << " " << target
290 // << " d:" << itarg->second.deads << "\n";
295 void yf::LoadBalance::Impl::add_package(unsigned long session_id)
297 std::string target = find_session_target(session_id);
299 if (target.size() != 0)
301 std::map<std::string, TargetStat>::iterator itarg;
302 itarg = m_target_stat.find(target);
303 if (itarg != m_target_stat.end()
304 && itarg->second.packages
305 < std::numeric_limits<unsigned int>::max())
307 itarg->second.packages += 1;
312 void yf::LoadBalance::Impl::remove_package(unsigned long session_id)
314 std::string target = find_session_target(session_id);
316 if (target.size() != 0)
318 std::map<std::string, TargetStat>::iterator itarg;
319 itarg = m_target_stat.find(target);
320 if (itarg != m_target_stat.end()
321 && itarg->second.packages > 0)
323 itarg->second.packages -= 1;
328 void yf::LoadBalance::Impl::add_session(unsigned long session_id,
331 // finding and adding session
332 std::map<unsigned long, std::string>::iterator isess;
333 isess = m_session_target.find(session_id);
334 if (isess == m_session_target.end())
336 m_session_target.insert(std::make_pair(session_id, target));
339 // finding and adding target statistics
340 std::map<std::string, TargetStat>::iterator itarg;
341 itarg = m_target_stat.find(target);
342 if (itarg == m_target_stat.end())
348 m_target_stat.insert(std::make_pair(target, stat));
350 else if (itarg->second.sessions < std::numeric_limits<unsigned int>::max())
352 itarg->second.sessions += 1;
356 void yf::LoadBalance::Impl::remove_session(unsigned long session_id)
361 std::map<unsigned long, std::string>::iterator isess;
362 isess = m_session_target.find(session_id);
363 if (isess == m_session_target.end())
366 target = isess->second;
368 // finding target statistics
369 std::map<std::string, TargetStat>::iterator itarg;
370 itarg = m_target_stat.find(target);
371 if (itarg == m_target_stat.end())
373 m_session_target.erase(isess);
377 // counting session down
378 if (itarg->second.sessions > 0)
379 itarg->second.sessions -= 1;
381 if (itarg->second.sessions == 0 && itarg->second.deads == 0)
383 m_target_stat.erase(itarg);
384 m_session_target.erase(isess);
388 std::string yf::LoadBalance::Impl::find_session_target(unsigned long session_id)
391 std::map<unsigned long, std::string>::iterator isess;
392 isess = m_session_target.find(session_id);
393 if (isess != m_session_target.end())
394 target = isess->second;
400 unsigned int yf::LoadBalance::Impl::cost(std::string target)
402 unsigned int cost = 0;
404 if (target.size() != 0)
406 std::map<std::string, TargetStat>::iterator itarg;
407 itarg = m_target_stat.find(target);
408 if (itarg != m_target_stat.end())
409 cost = itarg->second.cost();
414 unsigned int yf::LoadBalance::Impl::dead(std::string target)
416 unsigned int dead = 0;
418 if (target.size() != 0)
420 std::map<std::string, TargetStat>::iterator itarg;
421 itarg = m_target_stat.find(target);
422 if (itarg != m_target_stat.end())
423 dead = itarg->second.deads;
429 static mp::filter::Base* filter_creator()
431 return new mp::filter::LoadBalance;
435 struct metaproxy_1_filter_struct metaproxy_1_filter_load_balance = {
446 * c-file-style: "Stroustrup"
447 * indent-tabs-mode: nil
449 * vim: shiftwidth=4 tabstop=8 expandtab