From 02e4dbf521762a71750d75317ea8c97264efa3d9 Mon Sep 17 00:00:00 2001 From: Adam Dickmeiss Date: Tue, 24 Apr 2012 12:08:36 +0200 Subject: [PATCH] zoom: properly handle proxy failover for re-used backends Also log the diagnostic that is received from the backend in case of retry/failover because they will be not be returned via Z39.50/SRU. --- src/filter_zoom.cpp | 80 ++++++++++++++++++++++++++++++++++----------------- 1 file changed, 54 insertions(+), 26 deletions(-) diff --git a/src/filter_zoom.cpp b/src/filter_zoom.cpp index 0f340a0..0c02b58 100644 --- a/src/filter_zoom.cpp +++ b/src/filter_zoom.cpp @@ -97,6 +97,7 @@ namespace metaproxy_1 { bool enable_cproxy; bool enable_explain; xmlDoc *explain_doc; + std::string m_proxy; public: Backend(); ~Backend(); @@ -134,8 +135,7 @@ namespace metaproxy_1 { int *error, char **addinfo, mp::odr &odr, - int *proxy_step, - std::string &proxy); + int *proxy_step); bool create_content_session(mp::Package &package, BackendPtr b, @@ -977,15 +977,17 @@ bool yf::Zoom::Frontend::create_content_session(mp::Package &package, yf::Zoom::BackendPtr yf::Zoom::Frontend::get_backend_from_databases( mp::Package &package, std::string &database, int *error, char **addinfo, mp::odr &odr, - int *proxy_step, std::string &proxy) + int *proxy_step) { - proxy.clear(); + bool connection_reuse = false; + std::string proxy; + std::list::const_iterator map_it; if (m_backend && !m_backend->enable_explain && m_backend->m_frontend_database == database) { - m_backend->connect("", error, addinfo, odr); - return m_backend; + connection_reuse = true; + proxy = m_backend->m_proxy; } std::string input_args; @@ -1049,15 +1051,31 @@ yf::Zoom::BackendPtr yf::Zoom::Frontend::get_backend_from_databases( char **dstr; int dnum = 0; nmem_strsplit(((ODR) odr)->mem, ",", value, &dstr, &dnum); - if (*proxy_step >= dnum) - *proxy_step = 0; + if (connection_reuse) + { + // find the step after our current proxy + int i; + for (i = 0; i < dnum; i++) + if (!strcmp(proxy.c_str(), dstr[i])) + break; + if (i >= dnum - 1) + *proxy_step = 0; + else + *proxy_step = i + 1; + } else { - proxy = dstr[*proxy_step]; - - (*proxy_step)++; - if (*proxy_step == dnum) + // step is known.. Guess our proxy from it + if (*proxy_step >= dnum) *proxy_step = 0; + else + { + proxy = dstr[*proxy_step]; + + (*proxy_step)++; + if (*proxy_step == dnum) + *proxy_step = 0; + } } } else if (!strcmp(name, "cproxysession")) @@ -1082,7 +1100,16 @@ yf::Zoom::BackendPtr yf::Zoom::Frontend::get_backend_from_databases( *addinfo = msg; return notfound; } + } + if (proxy.length()) + package.log("zoom", YLOG_LOG, "proxy: %s", proxy.c_str()); + + if (connection_reuse) + { + m_backend->connect("", error, addinfo, odr); + return m_backend; } + if (param_user) { authentication = std::string(param_user); @@ -1225,6 +1252,7 @@ yf::Zoom::BackendPtr yf::Zoom::Frontend::get_backend_from_databases( BackendPtr b(new Backend); + b->m_proxy = proxy; b->sptr = sptr; b->xsp = xsp; b->m_frontend_database = database; @@ -1304,9 +1332,6 @@ yf::Zoom::BackendPtr yf::Zoom::Frontend::get_backend_from_databases( if (proxy.length()) b->set_option("proxy", proxy); } - if (proxy.length()) - package.log("zoom", YLOG_LOG, "proxy: %s", proxy.c_str()); - std::string url; if (sptr->sru.length()) { @@ -1916,21 +1941,20 @@ next_proxy: int error = 0; char *addinfo = 0; std::string db(sr->databaseNames[0]); - std::string proxy; BackendPtr b = get_backend_from_databases(package, db, &error, - &addinfo, odr, &proxy_step, - proxy); - + &addinfo, odr, &proxy_step); if (error) { - if (proxy.length() && !m_p->check_proxy(proxy.c_str())) + if (b && b->m_proxy.length() && !m_p->check_proxy(b->m_proxy.c_str())) { + log_diagnostic(package, error, addinfo); + package.log("zoom", YLOG_LOG, "proxy %s fails", b->m_proxy.c_str()); + m_backend.reset(); if (proxy_step) // there is a failover { proxy_retries++; package.log("zoom", YLOG_WARN, "search failed: trying next proxy"); - m_backend.reset(); goto next_proxy; } error = YAZ_BIB1_INIT_AC_AUTHENTICATION_SYSTEM_ERROR; @@ -1938,8 +1962,9 @@ next_proxy: } else if (same_retries == 0 && proxy_retries == 0) { + log_diagnostic(package, error, addinfo); same_retries++; - package.log("zoom", YLOG_WARN, "search failed: trying first proxy"); + package.log("zoom", YLOG_WARN, "search failed: retry"); m_backend.reset(); proxy_step = 0; goto next_proxy; @@ -2189,22 +2214,25 @@ next_proxy: if (error) { - if (proxy.length() && !m_p->check_proxy(proxy.c_str())) + if (b->m_proxy.length() && !m_p->check_proxy(b->m_proxy.c_str())) { + log_diagnostic(package, error, addinfo); + package.log("zoom", YLOG_LOG, "proxy %s fails", b->m_proxy.c_str()); + m_backend.reset(); if (proxy_step) // there is a failover { proxy_retries++; package.log("zoom", YLOG_WARN, "search failed: trying next proxy"); - m_backend.reset(); goto next_proxy; } error = YAZ_BIB1_INIT_AC_AUTHENTICATION_SYSTEM_ERROR; addinfo = odr_strdup(odr, "proxy failure"); } else if (same_retries == 0 && proxy_retries == 0) - { + { + log_diagnostic(package, error, addinfo); same_retries++; - package.log("zoom", YLOG_WARN, "search failed: trying first proxy"); + package.log("zoom", YLOG_WARN, "search failed: retry"); m_backend.reset(); proxy_step = 0; goto next_proxy; -- 1.7.10.4