Prevent multiplexing for cookie sessions

[yazpp-moved-to-github.git] / src / yaz-proxy.cpp

diff --git a/src/yaz-proxy.cpp b/src/yaz-proxy.cpp
index 49992a3..96054a3 100644 (file)
--- a/src/yaz-proxy.cpp
+++ b/src/yaz-proxy.cpp
@@ -2,7 +2,7 @@
  * Copyright (c) 1998-2003, Index Data.
  * See the file LICENSE for details.
  * 
- * $Id: yaz-proxy.cpp,v 1.51 2003-10-08 08:15:01 adam Exp $
+ * $Id: yaz-proxy.cpp,v 1.53 2003-10-08 09:49:05 adam Exp $
  */
 
 #include <assert.h>
@@ -158,6 +158,35 @@ 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, "%s zurl=%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);
@@ -170,6 +199,7 @@ Yaz_ProxyClient *Yaz_Proxy::get_client(Z_APDU *apdu)
 
     if (!m_proxyTarget)
     {
+       const char *url[MAX_ZURL_PLEX];
        const char *proxy_host = get_proxy(oi);
        if (proxy_host)
        {
@@ -178,9 +208,8 @@ Yaz_ProxyClient *Yaz_Proxy::get_client(Z_APDU *apdu)
            proxy_host = m_default_target;
        }
        
-       const char *url = 0;
        int client_idletime = -1;
-       m_config.get_target_info(proxy_host, &url, &m_keepalive, &m_bw_max,
+       m_config.get_target_info(proxy_host, url, &m_keepalive, &m_bw_max,
                                 &m_pdu_max, &m_max_record_retrieve,
                                 &m_target_idletime, &client_idletime,
                                 &parent->m_max_clients);
@@ -189,12 +218,18 @@ Yaz_ProxyClient *Yaz_Proxy::get_client(Z_APDU *apdu)
            m_client_idletime = client_idletime;
            timeout(m_client_idletime);
        }
-       if (!url)
+       if (!url[0])
        {
            yaz_log(LOG_LOG, "%s No default target", m_session_str);
            return 0;
        }
-       m_proxyTarget = (char*) xstrdup(url);
+       // 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)
     {
@@ -302,10 +337,10 @@ 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++;