Move config.xml, yaz-proxy.sh to etc
[yazpp-moved-to-github.git] / src / yaz-proxy.cpp
index ab518e7..5864a12 100644 (file)
  * Copyright (c) 1998-2003, Index Data.
  * See the file LICENSE for details.
  * 
- * $Id: yaz-proxy.cpp,v 1.47 2003-09-03 11:30:26 adam Exp $
+ * $Id: yaz-proxy.cpp,v 1.69 2003-10-23 13:59:37 adam Exp $
  */
 
 #include <assert.h>
 #include <time.h>
 
+#include <yaz/marcdisp.h>
+#include <yaz/yaz-iconv.h>
 #include <yaz/log.h>
+#include <yaz/diagbib1.h>
 #include <yaz++/proxy.h>
 
-Yaz_Proxy::Yaz_Proxy(IYaz_PDU_Observable *the_PDU_Observable) :
-    Yaz_Z_Assoc(the_PDU_Observable)
+static const char *apdu_name(Z_APDU *apdu)
+{
+    switch (apdu->which)
+    {
+    case Z_APDU_initRequest:
+        return "initRequest";
+    case Z_APDU_initResponse:
+        return "initResponse";
+    case Z_APDU_searchRequest:
+       return "searchRequest";
+    case Z_APDU_searchResponse:
+       return "searchResponse";
+    case Z_APDU_presentRequest:
+       return "presentRequest";
+    case Z_APDU_presentResponse:
+       return "presentResponse";
+    case Z_APDU_deleteResultSetRequest:
+       return "deleteResultSetRequest";
+    case Z_APDU_deleteResultSetResponse:
+       return "deleteResultSetResponse";
+    case Z_APDU_scanRequest:
+       return "scanRequest";
+    case Z_APDU_scanResponse:
+       return "scanResponse";
+    case Z_APDU_sortRequest:
+       return "sortRequest";
+    case Z_APDU_sortResponse:
+       return "sortResponse";
+    case Z_APDU_extendedServicesRequest:
+       return "extendedServicesRequest";
+    case Z_APDU_extendedServicesResponse:
+       return "extendedServicesResponse";
+    case Z_APDU_close:
+       return "close";
+    }
+    return "other";
+}
+
+Yaz_Proxy::Yaz_Proxy(IYaz_PDU_Observable *the_PDU_Observable,
+                    Yaz_Proxy *parent) :
+    Yaz_Z_Assoc(the_PDU_Observable), m_bw_stat(60), m_pdu_stat(60)
 {
     m_PDU_Observable = the_PDU_Observable;
     m_client = 0;
-    m_parent = 0;
+    m_parent = parent;
     m_clientPool = 0;
     m_seqno = 1;
-    m_keepalive = 1;
+    m_keepalive_limit_bw = 500000;
+    m_keepalive_limit_pdu = 1000;
     m_proxyTarget = 0;
+    m_default_target = 0;
     m_proxy_authentication = 0;
     m_max_clients = 150;
+    m_log_mask = 0;
     m_seed = time(0);
-    m_idletime = 600;
+    m_client_idletime = 600;
+    m_target_idletime = 600;
     m_optimize = xstrdup ("1");
+    strcpy(m_session_str, "0 ");
+    m_session_no=0;
+    m_bytes_sent = m_bytes_recv = 0;
+    m_bw_hold_PDU = 0;
+    m_bw_max = 0;
+    m_pdu_max = 0;
+    m_max_record_retrieve = 0;
+    m_reconfig_flag = 0;
+    m_config_fname = 0;
+    m_request_no = 0;
+    m_invalid_session = 0;
+    m_config = 0;
+    m_marcxml_flag = 0;
 }
 
 Yaz_Proxy::~Yaz_Proxy()
 {
+    yaz_log(LOG_LOG, "%sClosed %d/%d sent/recv bytes total", m_session_str,
+           m_bytes_sent, m_bytes_recv);
     xfree (m_proxyTarget);
+    xfree (m_default_target);
     xfree (m_proxy_authentication);
     xfree (m_optimize);
+    delete m_config;
 }
 
-void Yaz_Proxy::set_proxy_target(const char *target)
+int Yaz_Proxy::set_config(const char *config)
 {
-    xfree (m_proxyTarget);
-    m_proxyTarget = 0;
+    delete m_config;
+    m_config = new Yaz_ProxyConfig();
+    xfree(m_config_fname);
+    m_config_fname = xstrdup(config);
+    int r = m_config->read_xml(config);
+    if (!r)
+       m_config->get_generic_info(&m_log_mask, &m_max_clients);
+    return r;
+}
+
+void Yaz_Proxy::set_default_target(const char *target)
+{
+    xfree (m_default_target);
+    m_default_target = 0;
     if (target)
-       m_proxyTarget = (char *) xstrdup (target);
+       m_default_target = (char *) xstrdup (target);
 }
 
 void Yaz_Proxy::set_proxy_authentication (const char *auth)
@@ -51,16 +126,57 @@ void Yaz_Proxy::set_proxy_authentication (const char *auth)
        m_proxy_authentication = (char *) xstrdup (auth);
 }
 
+Yaz_ProxyConfig *Yaz_Proxy::check_reconfigure()
+{
+    if (m_parent)
+       return m_parent->check_reconfigure();
+
+    Yaz_ProxyConfig *cfg = m_config;
+    if (m_reconfig_flag)
+    {
+       yaz_log(LOG_LOG, "reconfigure");
+       yaz_log_reopen();
+       if (m_config_fname && cfg)
+       {
+           yaz_log(LOG_LOG, "reconfigure config %s", m_config_fname);
+           int r = cfg->read_xml(m_config_fname);
+           if (r)
+               yaz_log(LOG_WARN, "reconfigure failed");
+           else
+           {
+               m_log_mask = 0;
+               cfg->get_generic_info(&m_log_mask, &m_max_clients);
+           }
+       }
+       else
+           yaz_log(LOG_LOG, "reconfigure");
+       m_reconfig_flag = 0;
+    }
+    return cfg;
+}
+
 IYaz_PDU_Observer *Yaz_Proxy::sessionNotify(IYaz_PDU_Observable
                                            *the_PDU_Observable, int fd)
 {
-    Yaz_Proxy *new_proxy = new Yaz_Proxy(the_PDU_Observable);
-    new_proxy->m_parent = this;
-    new_proxy->timeout(m_idletime);
-    new_proxy->set_proxy_target(m_proxyTarget);
+    check_reconfigure();
+    Yaz_Proxy *new_proxy = new Yaz_Proxy(the_PDU_Observable, this);
+    new_proxy->m_config = 0;
+    new_proxy->m_config_fname = 0;
+    new_proxy->timeout(m_client_idletime);
+    new_proxy->m_target_idletime = m_target_idletime;
+    new_proxy->set_default_target(m_default_target);
+    new_proxy->m_max_clients = m_max_clients;
+    new_proxy->m_log_mask = m_log_mask;
     new_proxy->set_APDU_log(get_APDU_log());
+    if (m_log_mask & PROXY_LOG_APDU_CLIENT)
+       new_proxy->set_APDU_yazlog(1);
+    else
+       new_proxy->set_APDU_yazlog(0);
     new_proxy->set_proxy_authentication(m_proxy_authentication);
-    yaz_log (LOG_LOG, "New session p=%p", new_proxy);
+    sprintf(new_proxy->m_session_str, "%ld:%d ", (long) time(0), m_session_no);
+    m_session_no++;
+    yaz_log (LOG_LOG, "%sNew session %s", new_proxy->m_session_str,
+            the_PDU_Observable->getpeername());
     return new_proxy;
 }
 
@@ -96,6 +212,35 @@ char *Yaz_Proxy::get_proxy(Z_OtherInformation **otherInfo)
     return 0;
 }
 
+const char *Yaz_Proxy::load_balance(const char **url)
+{
+    int zurl_in_use[MAX_ZURL_PLEX];
+    Yaz_ProxyClient *c;
+    int i;
+
+    for (i = 0; i<MAX_ZURL_PLEX; i++)
+       zurl_in_use[i] = 0;
+    for (c = m_parent->m_clientPool; c; c = c->m_next)
+    {
+       for (i = 0; url[i]; i++)
+           if (!strcmp(url[i], c->get_hostname()))
+               zurl_in_use[i]++;
+    }
+    int min = 100000;
+    const char *ret = 0;
+    for (i = 0; url[i]; i++)
+    {
+       yaz_log(LOG_DEBUG, "%szurl=%s use=%d",
+               m_session_str, url[i], zurl_in_use[i]);
+       if (min > zurl_in_use[i])
+       {
+           ret = url[i];
+           min = zurl_in_use[i];
+       }
+    }
+    return ret;
+}
+
 Yaz_ProxyClient *Yaz_Proxy::get_client(Z_APDU *apdu)
 {
     assert (m_parent);
@@ -106,20 +251,56 @@ Yaz_ProxyClient *Yaz_Proxy::get_client(Z_APDU *apdu)
     get_otherInfoAPDU(apdu, &oi);
     char *cookie = get_cookie(oi);
 
-    const char *proxy_host = get_proxy(oi);
-    if (proxy_host)
-       set_proxy_target(proxy_host);
-    
-    // no target specified at all?
     if (!m_proxyTarget)
-       return 0;
-
-    if (!strcmp(m_proxyTarget, "stop"))
-       exit (0);
-    if (cookie && *cookie)
     {
-       Yaz_ProxyClient *cc = 0;
-       
+       const char *url[MAX_ZURL_PLEX];
+       const char *proxy_host = get_proxy(oi);
+       Yaz_ProxyConfig *cfg = check_reconfigure();
+       if (proxy_host)
+       {
+#if 0
+/* only to be enabled for debugging... */
+           if (!strcmp(proxy_host, "stop"))
+               exit(0);
+#endif
+           xfree(m_default_target);
+           m_default_target = xstrdup(proxy_host);
+           proxy_host = m_default_target;
+       }
+       int client_idletime = -1;
+       url[0] = m_default_target;
+       url[1] = 0;
+       if (cfg)
+       {
+           int pre_init = 0;
+           cfg->get_target_info(proxy_host, url, &m_bw_max,
+                                &m_pdu_max, &m_max_record_retrieve,
+                                &m_target_idletime, &client_idletime,
+                                &parent->m_max_clients,
+                                &m_keepalive_limit_bw,
+                                &m_keepalive_limit_pdu,
+                                &pre_init);
+       }
+       if (client_idletime != -1)
+       {
+           m_client_idletime = client_idletime;
+           timeout(m_client_idletime);
+       }
+       if (!url[0])
+       {
+           yaz_log(LOG_LOG, "%sNo default target", m_session_str);
+           return 0;
+       }
+       // we don't handle multiplexing for cookie session, so we just
+       // pick the first one in this case (anonymous users will be able
+       // to use any backend)
+       if (cookie && *cookie)
+           m_proxyTarget = (char*) xstrdup(url[0]);
+       else
+           m_proxyTarget = (char*) xstrdup(load_balance(url));
+    }
+    if (cookie && *cookie)
+    {   // search in sessions with a cookie
        for (c = parent->m_clientPool; c; c = c->m_next)
        {
            assert (c->m_prev);
@@ -127,68 +308,71 @@ Yaz_ProxyClient *Yaz_Proxy::get_client(Z_APDU *apdu)
            if (c->m_cookie && !strcmp(cookie,c->m_cookie) &&
                !strcmp(m_proxyTarget, c->get_hostname()))
            {
-               cc = c;
-           }
-       }
-       if (cc)
-       {
-           // found it in cache
-           c = cc;
-           // The following handles "cancel"
-           // If connection is busy (waiting for PDU) and
-           // we have an initRequest we can safely do re-open
-           if (c->m_waiting && apdu->which == Z_APDU_initRequest)
-           {
-               yaz_log (LOG_LOG, "reopen target=%s", c->get_hostname());
-               c->close();
-               c->client(m_proxyTarget);
-               c->m_init_flag = 0;
-
-               c->m_last_ok = 0;
-               c->m_cache.clear();
-               c->m_last_resultCount = 0;
-               c->m_sr_transform = 0;
-               c->m_waiting = 0;
-               c->m_resultSetStartPoint = 0;
-               c->timeout(m_idletime); 
+               // Found it in cache
+               // The following handles "cancel"
+               // If connection is busy (waiting for PDU) and
+               // we have an initRequest we can safely do re-open
+               if (c->m_waiting && apdu->which == Z_APDU_initRequest)
+               {
+                   yaz_log (LOG_LOG, "%s REOPEN target=%s", m_session_str,
+                            c->get_hostname());
+                   c->close();
+                   c->m_init_flag = 0;
+                   
+                   c->m_last_ok = 0;
+                   c->m_cache.clear();
+                   c->m_last_resultCount = 0;
+                   c->m_sr_transform = 0;
+                   c->m_waiting = 0;
+                   c->m_resultSetStartPoint = 0;
+                   c->m_target_idletime = m_target_idletime;
+                   if (c->client(m_proxyTarget))
+                   {
+                       delete c;
+                       return 0;
+                   }
+                   c->timeout(30); 
+               }
+               c->m_seqno = parent->m_seqno;
+               if (c->m_server && c->m_server != this)
+                   c->m_server->m_client = 0;
+               c->m_server = this;
+               (parent->m_seqno)++;
+               yaz_log (LOG_DEBUG, "get_client 1 %p %p", this, c);
+               return c;
            }
-           c->m_seqno = parent->m_seqno;
-           if (c->m_server && c->m_server != this)
-               c->m_server->m_client = 0;
-           c->m_server = this;
-           (parent->m_seqno)++;
-           yaz_log (LOG_DEBUG, "get_client 1 %p %p", this, c);
-           return c;
        }
     }
     else if (!c)
     {
-       Yaz_ProxyClient *cc = 0;
-       
+       // don't have a client session yet. Search in session w/o cookie
        for (c = parent->m_clientPool; c; c = c->m_next)
        {
            assert (c->m_prev);
            assert (*c->m_prev == c);
            if (c->m_server == 0 && c->m_cookie == 0 && 
+               c->m_waiting == 0 &&
                !strcmp(m_proxyTarget, c->get_hostname()))
            {
-               cc = c;
-           }
-       }
-       if (cc)
-       {
-           // found it in cache
-           c = cc;
+               // found it in cache
+               yaz_log (LOG_LOG, "%sREUSE %s",
+                        m_session_str, c->get_hostname());
+               
+               c->m_seqno = parent->m_seqno;
+               assert(c->m_server == 0);
+               c->m_server = this;
 
-           yaz_log (LOG_LOG, "Reuse session %d to %d %s",
-                    c->m_seqno, parent->m_seqno, c->get_hostname());
+               if (parent->m_log_mask & PROXY_LOG_APDU_SERVER)
+                   c->set_APDU_yazlog(1);
+               else
+                   c->set_APDU_yazlog(0);
 
-           c->m_seqno = parent->m_seqno;
-           assert(c->m_server == 0);
-           c->m_server = this;
-           
-           (parent->m_seqno)++;
-           return c;
+               (parent->m_seqno)++;
+               
+               parent->pre_init();
+               
+               return c;
+           }
        }
     }
     if (!m_client)
@@ -220,10 +404,10 @@ Yaz_ProxyClient *Yaz_Proxy::get_client(Z_APDU *apdu)
        int min_seq = -1;
        int no_of_clients = 0;
        if (parent->m_clientPool)
-           yaz_log (LOG_LOG, "Existing sessions");
+           yaz_log (LOG_DEBUG, "Existing sessions");
        for (c = parent->m_clientPool; c; c = c->m_next)
        {
-           yaz_log (LOG_LOG, " Session %-3d wait=%d %s cookie=%s", c->m_seqno,
+           yaz_log (LOG_DEBUG, " Session %-3d wait=%d %s cookie=%s", c->m_seqno,
                               c->m_waiting, c->get_hostname(),
                               c->m_cookie ? c->m_cookie : "");
            no_of_clients++;
@@ -238,16 +422,17 @@ Yaz_ProxyClient *Yaz_Proxy::get_client(Z_APDU *apdu)
            c = c_min;
            if (c->m_waiting || strcmp(m_proxyTarget, c->get_hostname()))
            {
-               yaz_log (LOG_LOG, "Replace session %d",
-                     c->m_seqno);
+               yaz_log (LOG_LOG, "%sMAXCLIENTS Destroy %d",
+                        m_session_str, c->m_seqno);
                if (c->m_server && c->m_server != this)
                    delete c->m_server;
                c->m_server = 0;
            }
            else
            {
-               yaz_log (LOG_LOG, "Move session %d to %d %s",
-                     c->m_seqno, parent->m_seqno, c->get_hostname());
+               yaz_log (LOG_LOG, "%sMAXCLIENTS Reuse %d %d %s",
+                        m_session_str,
+                        c->m_seqno, parent->m_seqno, c->get_hostname());
                xfree (c->m_cookie);
                c->m_cookie = 0;
                if (cookie)
@@ -259,15 +444,22 @@ Yaz_ProxyClient *Yaz_Proxy::get_client(Z_APDU *apdu)
                    delete c->m_server;
                }
                (parent->m_seqno)++;
-               yaz_log (LOG_DEBUG, "get_client 2 %p %p", this, c);
+               c->m_target_idletime = m_target_idletime;
+               c->timeout(m_target_idletime);
+               
+               if (parent->m_log_mask & PROXY_LOG_APDU_SERVER)
+                   c->set_APDU_yazlog(1);
+               else
+                   c->set_APDU_yazlog(0);
+
                return c;
            }
        }
        else
        {
-           yaz_log (LOG_LOG, "Making session %d %s", parent->m_seqno,
-                           m_proxyTarget);
-           c = new Yaz_ProxyClient(m_PDU_Observable->clone());
+           yaz_log (LOG_LOG, "%sNEW %d %s",
+                    m_session_str, parent->m_seqno, m_proxyTarget);
+           c = new Yaz_ProxyClient(m_PDU_Observable->clone(), parent);
            c->m_next = parent->m_clientPool;
            if (c->m_next)
                c->m_next->m_prev = &c->m_next;
@@ -280,9 +472,7 @@ Yaz_ProxyClient *Yaz_Proxy::get_client(Z_APDU *apdu)
        if (cookie)
            c->m_cookie = xstrdup(cookie);
 
-       yaz_log (LOG_LOG, "Connecting to %s", m_proxyTarget);
        c->m_seqno = parent->m_seqno;
-       c->client(m_proxyTarget);
        c->m_init_flag = 0;
        c->m_last_resultCount = 0;
         c->m_last_ok = 0;
@@ -290,33 +480,225 @@ Yaz_ProxyClient *Yaz_Proxy::get_client(Z_APDU *apdu)
        c->m_sr_transform = 0;
        c->m_waiting = 0;
        c->m_resultSetStartPoint = 0;
-       c->timeout(20);
-
        (parent->m_seqno)++;
+       if (c->client(m_proxyTarget))
+       {
+           delete c;
+           return 0;
+        }
+       c->m_target_idletime = m_target_idletime;
+       c->timeout(30);
+
+       if (parent->m_log_mask & PROXY_LOG_APDU_SERVER)
+           c->set_APDU_yazlog(1);
+       else
+           c->set_APDU_yazlog(0);
     }
     yaz_log (LOG_DEBUG, "get_client 3 %p %p", this, c);
     return c;
 }
 
+void Yaz_Proxy::display_diagrecs(Z_DiagRec **pp, int num)
+{
+    int i;
+    for (i = 0; i<num; i++)
+    {
+       oident *ent;
+       Z_DefaultDiagFormat *r;
+        Z_DiagRec *p = pp[i];
+        if (p->which != Z_DiagRec_defaultFormat)
+        {
+           yaz_log(LOG_LOG, "%sError no diagnostics", m_session_str);
+            return;
+        }
+        else
+            r = p->u.defaultFormat;
+        if (!(ent = oid_getentbyoid(r->diagnosticSetId)) ||
+            ent->oclass != CLASS_DIAGSET || ent->value != VAL_BIB1)
+           yaz_log(LOG_LOG, "%sError unknown diagnostic set", m_session_str);
+        switch (r->which)
+        {
+        case Z_DefaultDiagFormat_v2Addinfo:
+           yaz_log(LOG_LOG, "%sError %d %s:%s",
+                   m_session_str,
+                   *r->condition, diagbib1_str(*r->condition),
+                   r->u.v2Addinfo);
+            break;
+        case Z_DefaultDiagFormat_v3Addinfo:
+           yaz_log(LOG_LOG, "%sError %d %s:%s",
+                   m_session_str,
+                   *r->condition, diagbib1_str(*r->condition),
+                   r->u.v3Addinfo);
+            break;
+        }
+    }
+}
+
+void Yaz_Proxy::convert_to_marcxml(Z_NamePlusRecordList *p)
+{
+    int i;
+
+    yaz_marc_t mt = yaz_marc_create();
+    yaz_marc_xml(mt, YAZ_MARC_MARCXML);
+    for (i = 0; i < p->num_records; i++)
+    {
+       Z_NamePlusRecord *npr = p->records[i];
+       if (npr->which == Z_NamePlusRecord_databaseRecord)
+       {
+           Z_External *r = npr->u.databaseRecord;
+           if (r->which == Z_External_octet)
+           {
+               int rlen;
+               char *result;
+               if (yaz_marc_decode_buf(mt, (char*) r->u.octet_aligned->buf,
+                                       r->u.octet_aligned->len,
+                                       &result, &rlen))
+               {
+                   yaz_iconv_t cd = yaz_iconv_open("UTF-8", "MARC-8");
+                   WRBUF wrbuf = wrbuf_alloc();
+                   
+                   char outbuf[120];
+                   size_t inbytesleft = rlen;
+                   const char *inp = result;
+                   while (cd && inbytesleft)
+                   {
+                       size_t outbytesleft = sizeof(outbuf);
+                       char *outp = outbuf;
+                       size_t r;
+                       
+                       r = yaz_iconv (cd, (char**) &inp,
+                                      &inbytesleft,
+                                      &outp, &outbytesleft);
+                       if (r == (size_t) (-1))
+                       {
+                           int e = yaz_iconv_error(cd);
+                           if (e != YAZ_ICONV_E2BIG)
+                           {
+                               yaz_log(LOG_WARN, "conversion failure");
+                               break;
+                           }
+                       }
+                       wrbuf_write(wrbuf, outbuf, outp - outbuf);
+                   }
+                   if (cd)
+                       yaz_iconv_close(cd);
+
+                   npr->u.databaseRecord = z_ext_record(odr_encode(),
+                                                        VAL_TEXT_XML,
+                                                        wrbuf_buf(wrbuf),
+                                                        wrbuf_len(wrbuf));
+                   wrbuf_free(wrbuf, 1);
+               }
+           }
+       }
+    }
+    yaz_marc_destroy(mt);
+}
+
+int Yaz_Proxy::send_to_client(Z_APDU *apdu)
+{
+    int len = 0;
+    if (apdu->which == Z_APDU_searchResponse)
+    {
+       Z_SearchResponse *sr = apdu->u.searchResponse;
+       Z_Records *p = sr->records;
+       if (p && p->which == Z_Records_NSD)
+       {
+           Z_DiagRec dr, *dr_p = &dr;
+           dr.which = Z_DiagRec_defaultFormat;
+           dr.u.defaultFormat = p->u.nonSurrogateDiagnostic;
+
+           display_diagrecs(&dr_p, 1);
+       }
+       else
+       {
+           if (m_marcxml_flag && p && p->which == Z_Records_DBOSD)
+               convert_to_marcxml(p->u.databaseOrSurDiagnostics);
+           if (sr->resultCount)
+           {
+               yaz_log(LOG_LOG, "%s%d hits", m_session_str,
+                       *sr->resultCount);
+               if (*sr->resultCount < 0)
+                   m_invalid_session = 1;
+           }
+       }
+    }
+    else if (apdu->which == Z_APDU_presentResponse)
+    {
+       Z_PresentResponse *sr = apdu->u.presentResponse;
+       Z_Records *p = sr->records;
+       if (p && p->which == Z_Records_NSD)
+       {
+           Z_DiagRec dr, *dr_p = &dr;
+           dr.which = Z_DiagRec_defaultFormat;
+           dr.u.defaultFormat = p->u.nonSurrogateDiagnostic;
+
+           display_diagrecs(&dr_p, 1);
+       }
+       if (m_marcxml_flag && p && p->which == Z_Records_DBOSD)
+           convert_to_marcxml(p->u.databaseOrSurDiagnostics);
+    }
+    int r = send_Z_PDU(apdu, &len);
+    if (m_log_mask & PROXY_LOG_APDU_CLIENT)
+       yaz_log (LOG_DEBUG, "%sSending %s to client %d bytes", m_session_str,
+                apdu_name(apdu), len);
+    m_bytes_sent += len;
+    m_bw_stat.add_bytes(len);
+    return r;
+}
+
+int Yaz_ProxyClient::send_to_target(Z_APDU *apdu)
+{
+    int len = 0;
+    int r = send_Z_PDU(apdu, &len);
+    if (m_root->get_log_mask() & PROXY_LOG_REQ_SERVER)
+       yaz_log (LOG_LOG, "%sSending %s to %s %d bytes",
+                get_session_str(),
+                apdu_name(apdu), get_hostname(), len);
+    m_bytes_sent += len;
+    return r;
+}
+
 Z_APDU *Yaz_Proxy::result_set_optimize(Z_APDU *apdu)
 {
-    if (*m_parent->m_optimize == '0')
-        return apdu;      // don't optimize result sets..
     if (apdu->which == Z_APDU_presentRequest)
     {
        Z_PresentRequest *pr = apdu->u.presentRequest;
-       Z_NamePlusRecordList *npr;
        int toget = *pr->numberOfRecordsRequested;
        int start = *pr->resultSetStartPoint;
 
-       if (m_client->m_last_resultSetId &&
-           !strcmp(m_client->m_last_resultSetId, pr->resultSetId))
+       yaz_log(LOG_LOG, "%sPresent %s %d+%d", m_session_str,
+               pr->resultSetId, start, toget);
+
+       if (*m_parent->m_optimize == '0')
+           return apdu;
+
+       if (!m_client->m_last_resultSetId)
        {
+           Z_APDU *new_apdu = create_Z_PDU(Z_APDU_presentResponse);
+           new_apdu->u.presentResponse->records =
+               create_nonSurrogateDiagnostics(odr_encode(), 30,
+                                              pr->resultSetId);
+           send_to_client(new_apdu);
+           return 0;
+       }
+#if 0
+       if (!strcmp(m_client->m_last_resultSetId, pr->resultSetId))
+       {
+           if (start+toget-1 > m_client->m_last_resultCount)
+           {
+               Z_APDU *new_apdu = create_Z_PDU(Z_APDU_presentResponse);
+               new_apdu->u.presentResponse->records =
+                   create_nonSurrogateDiagnostics(odr_encode(), 13, 0);
+               send_to_client(new_apdu);
+               return 0;
+           }
            if (m_client->m_cache.lookup (odr_encode(), &npr, start, toget,
                                          pr->preferredRecordSyntax,
                                          pr->recordComposition))
            {
-               yaz_log (LOG_LOG, "Returned cache records for present request");
+               yaz_log (LOG_LOG, "%sReturned cached records for present request", 
+                        m_session_str);
                Z_APDU *new_apdu = create_Z_PDU(Z_APDU_presentResponse);
                new_apdu->u.presentResponse->referenceId = pr->referenceId;
                
@@ -329,10 +711,12 @@ Z_APDU *Yaz_Proxy::result_set_optimize(Z_APDU *apdu)
                new_apdu->u.presentResponse->records->u.databaseOrSurDiagnostics = npr;
                new_apdu->u.presentResponse->nextResultSetPosition =
                    odr_intdup(odr_encode(), start+toget);
-               send_Z_PDU(new_apdu);
+
+               send_to_client(new_apdu);
                return 0;
            }
        }
+#endif
     }
 
     if (apdu->which != Z_APDU_searchRequest)
@@ -345,8 +729,13 @@ Z_APDU *Yaz_Proxy::result_set_optimize(Z_APDU *apdu)
                        sr->databaseNames);
     
     this_query->set_Z_Query(sr->query);
-    
-    if (m_client->m_last_ok && m_client->m_last_query &&
+
+    char query_str[120];
+    this_query->print(query_str, sizeof(query_str)-1);
+    yaz_log(LOG_LOG, "%sSearch %s", m_session_str, query_str);
+
+    if (*m_parent->m_optimize != '0' &&
+       m_client->m_last_ok && m_client->m_last_query &&
        m_client->m_last_query->match(this_query) &&
         !strcmp(m_client->m_last_resultSetId, sr->resultSetName) &&
         m_client->m_last_databases.match(this_databases))
@@ -373,7 +762,8 @@ Z_APDU *Yaz_Proxy::result_set_optimize(Z_APDU *apdu)
            if (m_client->m_cache.lookup (odr_encode(), &npr, 1, toget,
                                          sr->preferredRecordSyntax, comp))
            {
-               yaz_log (LOG_LOG, "Returned cache records for medium set");
+               yaz_log (LOG_LOG, "%sReturned cached records for medium set",
+                        m_session_str);
                Z_APDU *new_apdu = create_Z_PDU(Z_APDU_searchResponse);
                new_apdu->u.searchResponse->referenceId = sr->referenceId;
                new_apdu->u.searchResponse->resultCount =
@@ -390,14 +780,15 @@ Z_APDU *Yaz_Proxy::result_set_optimize(Z_APDU *apdu)
                new_apdu->u.searchResponse->records->u.databaseOrSurDiagnostics = npr;
                new_apdu->u.searchResponse->nextResultSetPosition =
                    odr_intdup(odr_encode(), toget+1);
-               send_Z_PDU(new_apdu);
+               send_to_client(new_apdu);
                return 0;
            }
            else
            {
                // medium Set
                // send present request (medium size)
-               yaz_log (LOG_LOG, "Optimizing search for medium set");
+               yaz_log (LOG_LOG, "%sOptimizing search for medium set",
+                        m_session_str);
 
                Z_APDU *new_apdu = create_Z_PDU(Z_APDU_presentRequest);
                Z_PresentRequest *pr = new_apdu->u.presentRequest;
@@ -414,12 +805,13 @@ Z_APDU *Yaz_Proxy::result_set_optimize(Z_APDU *apdu)
            m_client->m_last_resultCount <= 0)
        {
             // large set. Return pseudo-search response immediately
-           yaz_log (LOG_LOG, "Optimizing search for large set");
+           yaz_log (LOG_LOG, "%sOptimizing search for large set",
+                    m_session_str);
            Z_APDU *new_apdu = create_Z_PDU(Z_APDU_searchResponse);
            new_apdu->u.searchResponse->referenceId = sr->referenceId;
            new_apdu->u.searchResponse->resultCount =
                &m_client->m_last_resultCount;
-           send_Z_PDU(new_apdu);
+           send_to_client(new_apdu);
            return 0;
        }
        else
@@ -441,7 +833,8 @@ Z_APDU *Yaz_Proxy::result_set_optimize(Z_APDU *apdu)
            if (m_client->m_cache.lookup (odr_encode(), &npr, 1, toget,
                                          sr->preferredRecordSyntax, comp))
            {
-               yaz_log (LOG_LOG, "Returned cache records for small set");
+               yaz_log (LOG_LOG, "%sReturned cached records for small set",
+                        m_session_str);
                Z_APDU *new_apdu = create_Z_PDU(Z_APDU_searchResponse);
                new_apdu->u.searchResponse->referenceId = sr->referenceId;
                new_apdu->u.searchResponse->resultCount =
@@ -458,12 +851,13 @@ Z_APDU *Yaz_Proxy::result_set_optimize(Z_APDU *apdu)
                new_apdu->u.searchResponse->records->u.databaseOrSurDiagnostics = npr;
                new_apdu->u.searchResponse->nextResultSetPosition =
                    odr_intdup(odr_encode(), toget+1);
-               send_Z_PDU(new_apdu);
+               send_to_client(new_apdu);
                return 0;
            }
            else
            {
-               yaz_log (LOG_LOG, "Optimizing search for small set");
+               yaz_log (LOG_LOG, "%sOptimizing search for small set",
+                        m_session_str);
                Z_APDU *new_apdu = create_Z_PDU(Z_APDU_presentRequest);
                Z_PresentRequest *pr = new_apdu->u.presentRequest;
                pr->referenceId = sr->referenceId;
@@ -476,7 +870,7 @@ Z_APDU *Yaz_Proxy::result_set_optimize(Z_APDU *apdu)
            }
        }
     }
-    else
+    else  // query doesn't match
     {
        delete m_client->m_last_query;
        m_client->m_last_query = this_query;
@@ -493,47 +887,197 @@ Z_APDU *Yaz_Proxy::result_set_optimize(Z_APDU *apdu)
     return apdu;
 }
 
-static const char *apdu_name(Z_APDU *apdu)
+
+void Yaz_Proxy::recv_Z_PDU(Z_APDU *apdu, int len)
 {
-    switch (apdu->which)
+    char *cp = strchr(m_session_str, ' ');
+    m_request_no++;
+    if (cp)
+       sprintf(cp+1, "%d ", m_request_no);
+
+    int reduce = 0;
+    m_bytes_recv += len;
+    
+    if (m_log_mask & PROXY_LOG_APDU_CLIENT)
+       yaz_log (LOG_DEBUG, "%sReceiving %s from client %d bytes",
+                m_session_str, apdu_name(apdu), len);
+
+    if (m_bw_hold_PDU)     // double incoming PDU. shutdown now.
+       shutdown();
+
+    m_bw_stat.add_bytes(len);
+    m_pdu_stat.add_bytes(1);
+
+    int bw_total = m_bw_stat.get_total();
+    int pdu_total = m_pdu_stat.get_total();
+
+    yaz_log(LOG_LOG, "%sstat bw=%d pdu=%d limit-bw=%d limit-pdu=%d",
+           m_session_str, bw_total, pdu_total, m_bw_max, m_pdu_max);
+    if (m_bw_max)
     {
-    case Z_APDU_initRequest:
-        return "initRequest";
-    case Z_APDU_initResponse:
-        return "initResponse";
-    case Z_APDU_searchRequest:
-       return "searchRequest";
-    case Z_APDU_searchResponse:
-       return "searchResponse";
-    case Z_APDU_presentRequest:
-       return "presentRequest";
-    case Z_APDU_presentResponse:
-       return "presentResponse";
-    case Z_APDU_deleteResultSetRequest:
-       return "deleteResultSetRequest";
-    case Z_APDU_deleteResultSetResponse:
-       return "deleteResultSetResponse";
-    case Z_APDU_scanRequest:
-       return "scanRequest";
-    case Z_APDU_scanResponse:
-       return "scanResponse";
-    case Z_APDU_sortRequest:
-       return "sortRequest";
-    case Z_APDU_sortResponse:
-       return "sortResponse";
-    case Z_APDU_extendedServicesRequest:
-       return "extendedServicesRequest";
-    case Z_APDU_extendedServicesResponse:
-       return "extendedServicesResponse";
-    case Z_APDU_close:
-       return "close";
+       if (bw_total > m_bw_max)
+       {
+           reduce = (bw_total/m_bw_max);
+       }
     }
-    return "other";
+    if (m_pdu_max)
+    {
+       if (pdu_total > m_pdu_max)
+       {
+           int nreduce = (60/m_pdu_max);
+           reduce = (reduce > nreduce) ? reduce : nreduce;
+       }
+    }
+    if (reduce)  
+    {
+       yaz_log(LOG_LOG, "%sLimit delay=%d", m_session_str, reduce);
+       m_bw_hold_PDU = apdu;  // save PDU and signal "on hold"
+       timeout(reduce);       // call us reduce seconds later
+    }
+    else
+       recv_Z_PDU_0(apdu);    // all fine. Proceed receive PDU as usual
+}
+
+void Yaz_Proxy::handle_max_record_retrieve(Z_APDU *apdu)
+{
+    if (m_max_record_retrieve)
+    {
+       if (apdu->which == Z_APDU_presentRequest)
+       {
+           Z_PresentRequest *pr = apdu->u.presentRequest;
+           if (pr->numberOfRecordsRequested && 
+               *pr->numberOfRecordsRequested > m_max_record_retrieve)
+               *pr->numberOfRecordsRequested = m_max_record_retrieve;
+       }
+    }
+}
+
+Z_Records *Yaz_Proxy::create_nonSurrogateDiagnostics(ODR odr,
+                                                    int error,
+                                                    const char *addinfo)
+{
+    Z_Records *rec = (Z_Records *)
+        odr_malloc (odr, sizeof(*rec));
+    int *err = (int *)
+        odr_malloc (odr, sizeof(*err));
+    Z_DiagRec *drec = (Z_DiagRec *)
+        odr_malloc (odr, sizeof(*drec));
+    Z_DefaultDiagFormat *dr = (Z_DefaultDiagFormat *)
+        odr_malloc (odr, sizeof(*dr));
+    *err = error;
+    rec->which = Z_Records_NSD;
+    rec->u.nonSurrogateDiagnostic = dr;
+    dr->diagnosticSetId =
+        yaz_oidval_to_z3950oid (odr, CLASS_DIAGSET, VAL_BIB1);
+    dr->condition = err;
+    dr->which = Z_DefaultDiagFormat_v2Addinfo;
+    dr->u.v2Addinfo = odr_strdup (odr, addinfo ? addinfo : "");
+    return rec;
+}
+
+Z_APDU *Yaz_Proxy::handle_query_validation(Z_APDU *apdu)
+{
+    if (apdu->which == Z_APDU_searchRequest)
+    {
+       Z_SearchRequest *sr = apdu->u.searchRequest;
+       int err = 0;
+       char *addinfo = 0;
+
+       Yaz_ProxyConfig *cfg = check_reconfigure();
+       if (cfg)
+           err = cfg->check_query(odr_encode(), m_default_target,
+                                  sr->query, &addinfo);
+       if (err)
+       {
+           Z_APDU *new_apdu = create_Z_PDU(Z_APDU_searchResponse);
+
+           new_apdu->u.searchResponse->referenceId = sr->referenceId;
+           new_apdu->u.searchResponse->records =
+               create_nonSurrogateDiagnostics(odr_encode(), err, addinfo);
+           *new_apdu->u.searchResponse->searchStatus = 0;
+
+           send_to_client(new_apdu);
+
+           return 0;
+       }
+    }
+    return apdu;
+}
+
+Z_APDU *Yaz_Proxy::handle_syntax_validation(Z_APDU *apdu)
+{
+    m_marcxml_flag = 0;
+    if (apdu->which == Z_APDU_searchRequest)
+    {
+       Z_SearchRequest *sr = apdu->u.searchRequest;
+       int err = 0;
+       char *addinfo = 0;
+       Yaz_ProxyConfig *cfg = check_reconfigure();
+       
+       if (cfg)
+           err = cfg->check_syntax(odr_encode(),
+                                   m_default_target,
+                                   sr->preferredRecordSyntax,
+                                   &addinfo);
+       if (err == -1)
+       {
+           sr->preferredRecordSyntax =
+               yaz_oidval_to_z3950oid(odr_decode(), CLASS_RECSYN,
+                                      VAL_USMARC);
+           m_marcxml_flag = 1;
+       }
+       else if (err)
+       {
+           Z_APDU *new_apdu = create_Z_PDU(Z_APDU_searchResponse);
+           
+           new_apdu->u.searchResponse->referenceId = sr->referenceId;
+           new_apdu->u.searchResponse->records =
+               create_nonSurrogateDiagnostics(odr_encode(), err, addinfo);
+           *new_apdu->u.searchResponse->searchStatus = 0;
+           
+           send_to_client(new_apdu);
+           
+           return 0;
+       }
+    }
+    else if (apdu->which == Z_APDU_presentRequest)
+    {
+       Z_PresentRequest *pr = apdu->u.presentRequest;
+       int err = 0;
+       char *addinfo = 0;
+       Yaz_ProxyConfig *cfg = check_reconfigure();
+
+       if (cfg)
+           err = cfg->check_syntax(odr_encode(), m_default_target,
+                                   pr->preferredRecordSyntax,
+                                   &addinfo);
+       if (err == -1)
+       {
+           pr->preferredRecordSyntax =
+               yaz_oidval_to_z3950oid(odr_decode(), CLASS_RECSYN,
+                                      VAL_USMARC);
+           m_marcxml_flag = 1;
+       }
+       else if (err)
+       {
+           Z_APDU *new_apdu = create_Z_PDU(Z_APDU_presentResponse);
+           
+           new_apdu->u.presentResponse->referenceId = pr->referenceId;
+           new_apdu->u.presentResponse->records =
+               create_nonSurrogateDiagnostics(odr_encode(), err, addinfo);
+           *new_apdu->u.presentResponse->presentStatus =
+               Z_PresentStatus_failure;
+           
+           send_to_client(new_apdu);
+           
+           return 0;
+       }
+    }
+    return apdu;
 }
 
-void Yaz_Proxy::recv_Z_PDU(Z_APDU *apdu)
+void Yaz_Proxy::recv_Z_PDU_0(Z_APDU *apdu)
 {
-    yaz_log (LOG_LOG, "Receiving %s from client", apdu_name(apdu));
     // Determine our client.
     m_client = get_client(apdu);
     if (!m_client)
@@ -545,6 +1089,15 @@ void Yaz_Proxy::recv_Z_PDU(Z_APDU *apdu)
 
     if (apdu->which == Z_APDU_initRequest)
     {
+       if (apdu->u.initRequest->implementationId)
+           yaz_log(LOG_LOG, "%simplementationId: %s",
+                   m_session_str, apdu->u.initRequest->implementationId);
+       if (apdu->u.initRequest->implementationName)
+           yaz_log(LOG_LOG, "%simplementationName: %s",
+                   m_session_str, apdu->u.initRequest->implementationName);
+       if (apdu->u.initRequest->implementationVersion)
+           yaz_log(LOG_LOG, "%simplementationVersion: %s",
+                   m_session_str, apdu->u.initRequest->implementationVersion);
        if (m_client->m_init_flag)
        {
            Z_APDU *apdu = m_client->m_initResponse;
@@ -552,17 +1105,27 @@ void Yaz_Proxy::recv_Z_PDU(Z_APDU *apdu)
            if (m_client->m_cookie && *m_client->m_cookie)
                set_otherInformationString(apdu, VAL_COOKIE, 1,
                                           m_client->m_cookie);
-           send_Z_PDU(apdu);
+           send_to_client(apdu);
            return;
        }
        m_client->m_init_flag = 1;
     }
-    apdu = result_set_optimize(apdu);
+    handle_max_record_retrieve(apdu);
+
+    if (apdu)
+       apdu = handle_syntax_validation(apdu);
+
+    if (apdu)
+       apdu = handle_query_validation(apdu);
+
+    if (apdu)
+       apdu = result_set_optimize(apdu);
     if (!apdu)
+    {
+       m_client->timeout(m_target_idletime);  // mark it active even 
+       // though we didn't use it
        return;
-
-    yaz_log (LOG_LOG, "Sending %s to %s",
-                   apdu_name(apdu), m_client->get_hostname());
+    }
 
     // delete other info part from PDU before sending to target
     Z_OtherInformation **oi;
@@ -579,7 +1142,7 @@ void Yaz_Proxy::recv_Z_PDU(Z_APDU *apdu)
     } else {
        m_client->m_resultSetStartPoint = 0;
     }
-    if (m_client->send_Z_PDU(apdu) < 0)
+    if (m_client->send_to_target(apdu) < 0)
     {
        delete m_client;
        m_client = 0;
@@ -596,62 +1159,91 @@ void Yaz_Proxy::connectNotify()
 void Yaz_Proxy::shutdown()
 {
     // only keep if keep_alive flag is set...
-    if (m_keepalive && m_client && m_client->m_waiting == 0)
+    if (m_client && 
+       !m_invalid_session &&
+       m_client->m_pdu_recv < m_keepalive_limit_pdu &&
+       m_client->m_bytes_recv+m_client->m_bytes_sent < m_keepalive_limit_bw &&
+       m_client->m_waiting == 0)
     {
-        yaz_log (LOG_LOG, "shutdown (client to proxy) keepalive %s",
+        yaz_log(LOG_LOG, "%sShutdown (client to proxy) keepalive %s",
+                m_session_str,
                  m_client->get_hostname());
+       yaz_log(LOG_LOG, "%sbw=%d pdu=%d limit-bw=%d limit-pdu=%d",
+               m_session_str, m_client->m_pdu_recv,
+               m_client->m_bytes_sent + m_client->m_bytes_recv,
+               m_keepalive_limit_bw, m_keepalive_limit_pdu);
         assert (m_client->m_waiting != 2);
        // Tell client (if any) that no server connection is there..
        m_client->m_server = 0;
     }
     else if (m_client)
     {
-        yaz_log (LOG_LOG, "shutdown (client to proxy) close %s",
+        yaz_log (LOG_LOG, "%sShutdown (client to proxy) close %s",
+                m_session_str,
                  m_client->get_hostname());
         assert (m_client->m_waiting != 2);
        delete m_client;
     }
     else if (!m_parent)
     {
-        yaz_log (LOG_LOG, "shutdown (client to proxy) bad state");
+        yaz_log (LOG_LOG, "%sshutdown (client to proxy) bad state",
+                m_session_str);
         assert (m_parent);
     }
     else 
     {
-        yaz_log (LOG_LOG, "shutdown (client to proxy)");
+        yaz_log (LOG_LOG, "%sShutdown (client to proxy)",
+                m_session_str);
     }
+    if (m_parent)
+       m_parent->pre_init();
     delete this;
 }
 
+const char *Yaz_ProxyClient::get_session_str() 
+{
+    if (!m_server)
+       return "0 ";
+    return m_server->get_session_str();
+}
+
 void Yaz_ProxyClient::shutdown()
 {
-    yaz_log (LOG_LOG, "shutdown (proxy to server) %s", get_hostname());
+    yaz_log (LOG_LOG, "%sShutdown (proxy to target) %s", get_session_str(),
+            get_hostname());
     delete m_server;
     delete this;
 }
 
 void Yaz_Proxy::failNotify()
 {
-    yaz_log (LOG_LOG, "Yaz_Proxy connection closed by client");
+    yaz_log (LOG_LOG, "%sConnection closed by client",
+            get_session_str());
     shutdown();
 }
 
 void Yaz_ProxyClient::failNotify()
 {
-    yaz_log (LOG_LOG, "Yaz_ProxyClient connection closed by %s", get_hostname());
+    yaz_log (LOG_LOG, "%sConnection closed by target %s", 
+            get_session_str(), get_hostname());
     shutdown();
 }
 
 void Yaz_ProxyClient::connectNotify()
 {
-    yaz_log (LOG_LOG, "Connection accepted by %s", get_hostname());
-    timeout(600);
+    const char *s = get_session_str();
+    const char *h = get_hostname();
+    yaz_log (LOG_LOG, "%sConnection accepted by %s timeout=%d", s, h,
+            m_target_idletime);
+    timeout(m_target_idletime);
+    if (!m_server)
+       pre_init_client();
 }
 
 IYaz_PDU_Observer *Yaz_ProxyClient::sessionNotify(IYaz_PDU_Observable
                                                  *the_PDU_Observable, int fd)
 {
-    return new Yaz_ProxyClient(the_PDU_Observable);
+    return new Yaz_ProxyClient(the_PDU_Observable, 0);
 }
 
 Yaz_ProxyClient::~Yaz_ProxyClient()
@@ -667,19 +1259,155 @@ Yaz_ProxyClient::~Yaz_ProxyClient()
     xfree (m_cookie);
 }
 
+void Yaz_ProxyClient::pre_init_client()
+{
+    Z_APDU *apdu = create_Z_PDU(Z_APDU_initRequest);
+    Z_InitRequest *req = apdu->u.initRequest;
+    
+    ODR_MASK_SET(req->options, Z_Options_search);
+    ODR_MASK_SET(req->options, Z_Options_present);
+    ODR_MASK_SET(req->options, Z_Options_namedResultSets);
+    ODR_MASK_SET(req->options, Z_Options_triggerResourceCtrl);
+    ODR_MASK_SET(req->options, Z_Options_scan);
+    ODR_MASK_SET(req->options, Z_Options_sort);
+    ODR_MASK_SET(req->options, Z_Options_extendedServices);
+    ODR_MASK_SET(req->options, Z_Options_delSet);
+    
+    ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_1);
+    ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_2);
+    ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_3);
+    
+    if (send_to_target(apdu) < 0)
+    {
+       delete this;
+    }
+    else
+    {
+       m_waiting = 1;
+       m_init_flag = 1;
+    }
+}
+
+void Yaz_Proxy::pre_init()
+{
+    int i;
+    const char *name = 0;
+    const char *zurl_in_use[MAX_ZURL_PLEX];
+    int limit_bw, limit_pdu, limit_req;
+    int target_idletime, client_idletime;
+    int max_clients;
+    int keepalive_limit_bw, keepalive_limit_pdu;
+    int pre_init;
+
+    Yaz_ProxyConfig *cfg = check_reconfigure();
+
+    zurl_in_use[0] = 0;
+
+    if (m_log_mask & PROXY_LOG_APDU_CLIENT)
+       set_APDU_yazlog(1);
+    else
+       set_APDU_yazlog(0);
+
+    for (i = 0; cfg && cfg->get_target_no(i, &name, zurl_in_use,
+                                         &limit_bw, &limit_pdu, &limit_req,
+                                         &target_idletime, &client_idletime,
+                                         &max_clients, 
+                                         &keepalive_limit_bw,
+                                         &keepalive_limit_pdu,
+                                         &pre_init) ; i++)
+    {
+       if (pre_init)
+       {
+           int j;
+           for (j = 0; zurl_in_use[j]; j++)
+           {
+               Yaz_ProxyClient *c;
+               int spare = 0;
+               int in_use = 0;
+               int other = 0;
+               for (c = m_clientPool; c; c = c->m_next)
+               {
+                   if (!strcmp(zurl_in_use[j], c->get_hostname()))
+                   {
+                       if (c->m_cookie == 0)
+                       {
+                           if (c->m_server == 0)
+                               spare++;
+                           else
+                               in_use++;
+                       }
+                       else
+                           other++;
+                   }
+               }
+               yaz_log(LOG_LOG, "%spre-init %s %s use=%d other=%d spare=%d "
+                       "preinit=%d",m_session_str,
+                       name, zurl_in_use[j], in_use, other, spare, pre_init);
+               if (spare < pre_init)
+               {
+                   c = new Yaz_ProxyClient(m_PDU_Observable->clone(), this);
+                   c->m_next = m_clientPool;
+                   if (c->m_next)
+                       c->m_next->m_prev = &c->m_next;
+                   m_clientPool = c;
+                   c->m_prev = &m_clientPool;
+                   
+                   if (m_log_mask & PROXY_LOG_APDU_SERVER)
+                       c->set_APDU_yazlog(1);
+                   else
+                       c->set_APDU_yazlog(0);
+
+                   if (c->client(zurl_in_use[j]))
+                   {
+                       timeout(60);
+                       delete c;
+                       return;
+                   }
+                   c->timeout(30);
+                   c->m_waiting = 1;
+                   c->m_target_idletime = target_idletime;
+                   c->m_seqno = m_seqno++;
+               }
+           }
+       }
+    }
+}
+
 void Yaz_Proxy::timeoutNotify()
 {
-    yaz_log (LOG_LOG, "timeout (client to proxy)");
-    shutdown();
+    if (m_parent)
+    {
+       if (m_bw_hold_PDU)
+       {
+           timeout(m_client_idletime);
+           Z_APDU *apdu = m_bw_hold_PDU;
+           m_bw_hold_PDU = 0;
+           recv_Z_PDU_0(apdu);
+       }
+       else
+       {
+           yaz_log (LOG_LOG, "%sTimeout (client to proxy)", m_session_str);
+           shutdown();
+       }
+    }
+    else
+    {
+       timeout(600);
+       pre_init();
+    }
 }
 
 void Yaz_ProxyClient::timeoutNotify()
 {
-    yaz_log (LOG_LOG, "timeout (proxy to target) %s", get_hostname());
+    yaz_log (LOG_LOG, "%sTimeout (proxy to target) %s", get_session_str(),
+            get_hostname());
+    m_waiting = 1;
+    m_root->pre_init();
     shutdown();
 }
 
-Yaz_ProxyClient::Yaz_ProxyClient(IYaz_PDU_Observable *the_PDU_Observable) :
+Yaz_ProxyClient::Yaz_ProxyClient(IYaz_PDU_Observable *the_PDU_Observable,
+                                Yaz_Proxy *parent) :
     Yaz_Z_Assoc (the_PDU_Observable)
 {
     m_cookie = 0;
@@ -695,6 +1423,12 @@ Yaz_ProxyClient::Yaz_ProxyClient(IYaz_PDU_Observable *the_PDU_Observable) :
     m_init_odr = odr_createmem (ODR_DECODE);
     m_initResponse = 0;
     m_resultSetStartPoint = 0;
+    m_bytes_sent = m_bytes_recv = 0;
+    m_pdu_recv = 0;
+    m_server = 0;
+    m_seqno = 0;
+    m_target_idletime = 600;
+    m_root = parent;
 }
 
 const char *Yaz_Proxy::option(const char *name, const char *value)
@@ -709,17 +1443,37 @@ const char *Yaz_Proxy::option(const char *name, const char *value)
     return 0;
 }
 
-void Yaz_ProxyClient::recv_Z_PDU(Z_APDU *apdu)
+void Yaz_ProxyClient::recv_Z_PDU(Z_APDU *apdu, int len)
 {
+    m_bytes_recv += len;
+    m_pdu_recv++;
     m_waiting = 0;
-    yaz_log (LOG_LOG, "Receiving %s from %s", apdu_name(apdu),
-                    get_hostname());
+    if (m_root->get_log_mask() & PROXY_LOG_REQ_SERVER)
+       yaz_log (LOG_LOG, "%sReceiving %s from %s %d bytes", get_session_str(),
+                apdu_name(apdu), get_hostname(), len);
     if (apdu->which == Z_APDU_initResponse)
     {
+       if (!m_server)  // if this is a pre init session , check for more
+           m_root->pre_init();
         NMEM nmem = odr_extract_mem (odr_decode());
        odr_reset (m_init_odr);
         nmem_transfer (m_init_odr->mem, nmem);
         m_initResponse = apdu;
+
+       Z_InitResponse *ir = apdu->u.initResponse;
+       char *im0 = ir->implementationName;
+       
+       char *im1 = (char*) 
+           odr_malloc(m_init_odr, 20 + (im0 ? strlen(im0) : 0));
+       *im1 = '\0';
+       if (im0)
+       {
+           strcat(im1, im0);
+           strcat(im1, " ");
+       }
+       strcat(im1, "(YAZ Proxy)");
+       ir->implementationName = im1;
+
         nmem_destroy (nmem);
     }
     if (apdu->which == Z_APDU_searchResponse)
@@ -754,7 +1508,8 @@ void Yaz_ProxyClient::recv_Z_PDU(Z_APDU *apdu)
            sr->numberOfRecordsReturned = pr->numberOfRecordsReturned;
            apdu = new_apdu;
        }
-       if (pr->records->which == Z_Records_DBOSD && m_resultSetStartPoint)
+       if (pr->records && 
+           pr->records->which == Z_Records_DBOSD && m_resultSetStartPoint)
        {
            m_cache.add(odr_decode(),
                        pr->records->u.databaseOrSurDiagnostics,
@@ -766,11 +1521,22 @@ void Yaz_ProxyClient::recv_Z_PDU(Z_APDU *apdu)
        set_otherInformationString (apdu, VAL_COOKIE, 1, m_cookie);
     if (m_server)
     {
-       yaz_log (LOG_LOG, "Sending %s to client", apdu_name(apdu));
-       m_server->send_Z_PDU(apdu);
+       m_server->send_to_client(apdu);
     }
     if (apdu->which == Z_APDU_close)
     {
        shutdown();
     }
 }
+
+int Yaz_Proxy::server(const char *addr)
+{
+    int r = Yaz_Z_Assoc::server(addr);
+    if (!r)
+    {
+       yaz_log(LOG_LOG, "%sStarted listener on %s", m_session_str, addr);
+       timeout(1);
+    }
+    return r;
+}
+