1 /* This file is part of Metaproxy.
2 Copyright (C) 2005-2013 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>)
41 namespace mp = metaproxy_1;
42 namespace yf = mp::filter;
48 class LoadBalance::Impl
53 void process(metaproxy_1::Package & package);
54 void configure(const xmlNode * ptr);
56 // statistic manipulating functions,
57 void add_dead(unsigned long session_id);
58 //void clear_dead(unsigned long session_id);
59 void add_package(unsigned long session_id);
60 void remove_package(unsigned long session_id);
61 void add_session(unsigned long session_id, std::string target);
62 void remove_session(unsigned long session_id);
63 std::string find_session_target(unsigned long session_id);
66 unsigned int cost(std::string target);
67 unsigned int dead(std::string target);
72 unsigned int sessions;
73 unsigned int packages;
76 unsigned int c = sessions + packages + deads;
81 // local protected databases
83 std::map<std::string, TargetStat> m_target_stat;
84 std::map<unsigned long, std::string> m_session_target;
89 // define Pimpl wrapper forwarding to Impl
91 yf::LoadBalance::LoadBalance() : m_p(new Impl)
95 yf::LoadBalance::~LoadBalance()
96 { // must have a destructor because of boost::scoped_ptr
99 void yf::LoadBalance::configure(const xmlNode *xmlnode, bool test_only,
102 m_p->configure(xmlnode);
105 void yf::LoadBalance::process(mp::Package &package) const
107 m_p->process(package);
111 yf::LoadBalance::Impl::Impl()
115 yf::LoadBalance::Impl::~Impl()
119 void yf::LoadBalance::Impl::configure(const xmlNode *xmlnode)
123 void yf::LoadBalance::Impl::process(mp::Package &package)
125 bool is_closed_front = false;
127 // checking for closed front end packages
128 if (package.session().is_closed())
130 is_closed_front = true;
133 Z_GDU *gdu_req = package.request().get();
135 // passing anything but z3950 packages
136 if (gdu_req && gdu_req->which == Z_GDU_Z3950)
138 // target selecting only on Z39.50 init request
139 if (gdu_req->u.z3950->which == Z_APDU_initRequest)
141 yazpp_1::GDU base_req(gdu_req);
142 Z_APDU *apdu = base_req.get()->u.z3950;
144 Z_InitRequest *org_init = base_req.get()->u.z3950->u.initRequest;
145 mp::odr odr_en(ODR_ENCODE);
147 std::list<std::string> vhosts;
148 mp::util::remove_vhost_otherinfo(&(org_init->otherInfo), vhosts);
149 // get lowest of all vhosts.. Remove them if individually if
150 // they turn out to be bad..
154 std::list<std::string>::iterator ivh = vhosts.begin();
156 Package init_pkg(package.session(), package.origin());
157 init_pkg.copy_filter(package);
159 unsigned int cost = std::numeric_limits<unsigned int>::max();
161 boost::mutex::scoped_lock scoped_lock(m_mutex);
163 for (; ivh != vhosts.end(); )
165 if ((*ivh).size() != 0)
168 = yf::LoadBalance::Impl::cost(*ivh);
169 yaz_log(YLOG_LOG, "Consider %s cost=%u vhcost=%u",
170 (*ivh).c_str(), cost, vhcost);
175 ivh = vhosts.erase(ivh);
184 if (target.length() == 0)
186 // copying new target into init package
188 yazpp_1::GDU init_gdu(base_req);
189 Z_InitRequest *init_req = init_gdu.get()->u.z3950->u.initRequest;
191 mp::util::set_vhost_otherinfo(&(init_req->otherInfo),
194 init_pkg.request() = init_gdu;
196 // moving all package types
199 // checking for closed back end packages
200 if (!init_pkg.session().is_closed())
202 add_session(package.session().id(), target);
204 package.response() = init_pkg.response();
209 package.response() = odr.create_initResponse(
210 apdu, YAZ_BIB1_TEMPORARY_SYSTEM_ERROR,
211 "load_balance: no available targets");
212 package.session().close();
215 // frontend Z39.50 close request is added to statistics and marked
216 else if (gdu_req->u.z3950->which == Z_APDU_close)
218 is_closed_front = true;
219 boost::mutex::scoped_lock scoped_lock(m_mutex);
220 add_package(package.session().id());
222 // any other Z39.50 package is added to statistics
225 boost::mutex::scoped_lock scoped_lock(m_mutex);
226 add_package(package.session().id());
230 // moving all package types
233 bool is_closed_back = false;
235 // checking for closed back end packages
236 if (package.session().is_closed())
237 is_closed_back = true;
239 Z_GDU *gdu_res = package.response().get();
241 // passing anything but z3950 packages
242 if (gdu_res && gdu_res->which == Z_GDU_Z3950)
244 // session closing only on Z39.50 close response
245 if (gdu_res->u.z3950->which == Z_APDU_close)
247 is_closed_back = true;
248 boost::mutex::scoped_lock scoped_lock(m_mutex);
249 remove_package(package.session().id());
251 // any other Z39.50 package is removed from statistics
254 boost::mutex::scoped_lock scoped_lock(m_mutex);
255 remove_package(package.session().id());
259 // finally removing sessions and marking deads
260 if (is_closed_back || is_closed_front)
262 boost::mutex::scoped_lock scoped_lock(m_mutex);
264 // marking backend dead if backend closed without fronted close
265 if (is_closed_front == false)
266 add_dead(package.session().id());
268 remove_session(package.session().id());
270 // making sure that package is closed
271 package.session().close();
275 // statistic manipulating functions,
276 void yf::LoadBalance::Impl::add_dead(unsigned long session_id)
278 std::string target = find_session_target(session_id);
280 if (target.size() != 0)
282 std::map<std::string, TargetStat>::iterator itarg;
283 itarg = m_target_stat.find(target);
284 if (itarg != m_target_stat.end()
285 && itarg->second.deads < std::numeric_limits<unsigned int>::max())
287 itarg->second.deads += 1;
288 // std:.cout << "add_dead " << session_id << " " << target
289 // << " d:" << itarg->second.deads << "\n";
294 void yf::LoadBalance::Impl::add_package(unsigned long session_id)
296 std::string target = find_session_target(session_id);
298 if (target.size() != 0)
300 std::map<std::string, TargetStat>::iterator itarg;
301 itarg = m_target_stat.find(target);
302 if (itarg != m_target_stat.end()
303 && itarg->second.packages
304 < std::numeric_limits<unsigned int>::max())
306 itarg->second.packages += 1;
311 void yf::LoadBalance::Impl::remove_package(unsigned long session_id)
313 std::string target = find_session_target(session_id);
315 if (target.size() != 0)
317 std::map<std::string, TargetStat>::iterator itarg;
318 itarg = m_target_stat.find(target);
319 if (itarg != m_target_stat.end()
320 && itarg->second.packages > 0)
322 itarg->second.packages -= 1;
327 void yf::LoadBalance::Impl::add_session(unsigned long session_id,
330 // finding and adding session
331 std::map<unsigned long, std::string>::iterator isess;
332 isess = m_session_target.find(session_id);
333 if (isess == m_session_target.end())
335 m_session_target.insert(std::make_pair(session_id, target));
338 // finding and adding target statistics
339 std::map<std::string, TargetStat>::iterator itarg;
340 itarg = m_target_stat.find(target);
341 if (itarg == m_target_stat.end())
347 m_target_stat.insert(std::make_pair(target, stat));
349 else if (itarg->second.sessions < std::numeric_limits<unsigned int>::max())
351 itarg->second.sessions += 1;
355 void yf::LoadBalance::Impl::remove_session(unsigned long session_id)
360 std::map<unsigned long, std::string>::iterator isess;
361 isess = m_session_target.find(session_id);
362 if (isess == m_session_target.end())
365 target = isess->second;
367 // finding target statistics
368 std::map<std::string, TargetStat>::iterator itarg;
369 itarg = m_target_stat.find(target);
370 if (itarg == m_target_stat.end())
372 m_session_target.erase(isess);
376 // counting session down
377 if (itarg->second.sessions > 0)
378 itarg->second.sessions -= 1;
380 if (itarg->second.sessions == 0 && itarg->second.deads == 0)
382 m_target_stat.erase(itarg);
383 m_session_target.erase(isess);
387 std::string yf::LoadBalance::Impl::find_session_target(unsigned long session_id)
390 std::map<unsigned long, std::string>::iterator isess;
391 isess = m_session_target.find(session_id);
392 if (isess != m_session_target.end())
393 target = isess->second;
399 unsigned int yf::LoadBalance::Impl::cost(std::string target)
401 unsigned int cost = 0;
403 if (target.size() != 0)
405 std::map<std::string, TargetStat>::iterator itarg;
406 itarg = m_target_stat.find(target);
407 if (itarg != m_target_stat.end())
408 cost = itarg->second.cost();
413 unsigned int yf::LoadBalance::Impl::dead(std::string target)
415 unsigned int dead = 0;
417 if (target.size() != 0)
419 std::map<std::string, TargetStat>::iterator itarg;
420 itarg = m_target_stat.find(target);
421 if (itarg != m_target_stat.end())
422 dead = itarg->second.deads;
428 static mp::filter::Base* filter_creator()
430 return new mp::filter::LoadBalance;
434 struct metaproxy_1_filter_struct metaproxy_1_filter_load_balance = {
445 * c-file-style: "Stroustrup"
446 * indent-tabs-mode: nil
448 * vim: shiftwidth=4 tabstop=8 expandtab