From: aland <aland>
Date: Mon, 14 May 2007 11:17:32 +0000 (+0000)
Subject: 	Add new load balancing method "client-port-balance"
X-Git-Tag: release_2_0_0_pre1~20
X-Git-Url: http://www.project-moonshot.org/gitweb/?a=commitdiff_plain;h=6655f51fc26ce9d28e925316405eb4970df4202d;p=freeradius.git

	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
--- 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
--- 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
--- 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];