Add new load balancing method "client-port-balance"

	This method should be removed when we have state tracking of EAP
	proxies in a module

diff --git a/raddb/proxy.conf b/raddb/proxy.conf
index 1006821..a29cad4 100644 (file)
--- a/raddb/proxy.conf
+++ b/raddb/proxy.conf
@@ -317,14 +317,55 @@ home_server localhost {
 #
 server_pool my_auth_failover {
        #
-       #  The type of this pool is either "fail-over" or "load-balance".
-       #
-       #  With "fail-over", the request is sent to the first live
-       #  home server in the list.
-       #
-       #  With "load-balance", the request is load-balanced (randomly)
-       #  between the live home servers.  This is equivalent to the
-       #  old per-realm configuration "round_robin".
+       #  The type of this pool controls how home servers are chosen.
+       #
+       #  fail-over - the request is sent to the first live
+       #       home server in the list.  i.e. If the first home server
+       #       is marked "dead", the second one is chosen, etc.
+       #
+       #  load-balance - the least busy home server is chosen,
+       #       where "least busy" is counted by taking the number of
+       #       requests sent to that home server, and subtracting the
+       #       number of responses received from that home server.
+       #
+       #       If there are two or more servers with the same low
+       #       load, then one of those servers is chosen at random.
+       #       This configuration is most similar to the old
+       #       "round-robin" method, though it is not exactly the same.
+       #
+       #       Note that load balancing does not work well with EAP,
+       #       as EAP requires packets for an EAP conversation to be
+       #       sent to the same home server.  The load balancing method
+       #       does not keep state in between packets, meaning that
+       #       EAP packets for the same conversation may be sent to
+       #       different home servers.  This will prevent EAP from
+       #       working.
+       #
+       #       For non-EAP authentication methods, and for accounting
+       #       packets, we recommend using "load-balance".  It will
+       #       ensure the highest availability for your network.
+       #
+       #  client-balance - the home server is chosen by hashing the
+       #       source IP address of the packet.  If that home server
+       #       is down, the next one in the list is used, just as
+       #       with "fail-over".
+       #
+       #       There is no way of predicting which source IP will map
+       #       to which home server.
+       #
+       #       This configuration is most useful to do simple load
+       #       balancing for EAP sessions, as the EAP session will
+       #       always be sent to the same home server.
+       #
+       #  client-port-balance - the home server is chosen by hashing
+       #       the source IP address and source port of the packet.
+       #       If that home server is down, the next one in the list
+       #       is used, just as with "fail-over".
+       #
+       #       This method provides slightly better load balancing
+       #       for EAP sessions than "client-balance".  However, it
+       #       also means that authentication and accounting packets
+       #       for the same session MAY go to different home servers.
        #
        type = fail-over
 

diff --git a/src/include/realms.h b/src/include/realms.h
index 3c42c7f..7831017 100644 (file)
--- a/src/include/realms.h
+++ b/src/include/realms.h
@@ -69,7 +69,8 @@ typedef enum home_pool_type_t {
        HOME_POOL_INVALID = 0,
        HOME_POOL_LOAD_BALANCE,
        HOME_POOL_FAIL_OVER,
-       HOME_POOL_CLIENT_BALANCE
+       HOME_POOL_CLIENT_BALANCE,
+       HOME_POOL_CLIENT_PORT_BALANCE
 } home_pool_type_t;
 
 

diff --git a/src/main/realms.c b/src/main/realms.c
index d301dca..a2dd7b8 100644 (file)
--- a/src/main/realms.c
+++ b/src/main/realms.c
@@ -480,6 +480,7 @@ static int server_pool_add(const char *filename, CONF_SECTION *cs)
                        { "round_robin", HOME_POOL_LOAD_BALANCE },
                        { "fail_over", HOME_POOL_FAIL_OVER },
                        { "client-balance", HOME_POOL_CLIENT_BALANCE },
+                       { "client-port-balance", HOME_POOL_CLIENT_PORT_BALANCE },
                        { NULL, 0 }
                };
 
@@ -1064,6 +1065,25 @@ home_server *home_server_ldb(const char *realmname,
                start = hash % pool->num_home_servers;
                break;
 
+       case HOME_POOL_CLIENT_PORT_BALANCE:
+               switch (request->packet->src_ipaddr.af) {
+               case AF_INET:
+                       hash = lrad_hash(&request->packet->src_ipaddr.ipaddr.ip4addr,
+                                        sizeof(request->packet->src_ipaddr.ipaddr.ip4addr));
+                       break;
+               case AF_INET6:
+                       hash = lrad_hash(&request->packet->src_ipaddr.ipaddr.ip6addr,
+                                        sizeof(request->packet->src_ipaddr.ipaddr.ip6addr));
+                       break;
+               default:
+                       hash = 0;
+                       break;
+               }
+               lrad_hash_update(&request->packet->src_port,
+                                sizeof(request->packet->src_port), hash);
+               start = hash % pool->num_home_servers;
+               break;
+
        case HOME_POOL_LOAD_BALANCE:
                found = pool->servers[0];