Changes between Version 1 and Version 2 of TBFailOver

Timestamp:

Jun 21, 2010, 4:44:33 PM (14 years ago)

Author:

Sebastien Decugis

Comment:

--

TBFailOver

@@ -2 +2 @@
 == Failover testbed == 
 
-One of the great improvements of Diameter is the '''failover''' mechanism. This means that after a request has been sent by a Diameter node to another node, if this connection is down before the answer is received, the request is sent through another connection (when possible), so that the message can reach the final destination through a different route. Coupled with the watchdog mechanism of Diameter, this mechanism ensures that all requests receive an answer (which can be an error). The '''failback''' term means that after a connection has been restored, new messages are again sent to this peer.
+One of the great improvements of Diameter is the '''failover''' mechanism. 
 
-This testbed involves 4 nodes in two different realms: a client ({{{nas}}} in realm {{{a}}}), two relays ({{{proxy}}} in realm {{{a}}}, and {{{proxy}}} in realm {{{b}}}), and a server ({{{serv}}} in realm {{{b}}}). The client and server are using the [wiki:test_app.fdx test_app] application to exchange messages. The routing configuration allows the messages to be conveyed through one of the relays, but not directly between the client and server. In the graph bellow, the blue route is the primary route, and green is secondary in case the primary route is down.
+This mechanism works as follow: after a request has been sent or relayed by a node, if the connection it was sent over is teared down before the corresponding answer is received, the request must be sent again through another connection (when possible). The request will reach the final destination through a different route.
+
+Coupled with the watchdog mechanism of Diameter, this failover mechanism ensures that all requests receive an answer (which can be an error). The main drawbacks are that the same request may be received several times by the server (duplicates), and that there is no limit of time for receiving the answer to a message, which can create congestion in the Diameter network.
+
+The '''failback''' term means that after a connection has been restored, new messages are again sent to this peer.
+
+Failover and failback are '''natively supported''' by the {{{freeDiameter}}} daemon.
+
+This testbed involves 4 nodes in two different realms: a client ({{{nas}}} in realm {{{a}}}), two relays ({{{proxy}}} in realm {{{a}}}, and {{{proxy}}} in realm {{{b}}}), and a server ({{{serv}}} in realm {{{b}}}). 
+
+The client and server are using the [wiki:test_app.fdx test_app] application to exchange messages. The routing configuration allows the messages to be conveyed through one of the relays, but not directly between the client and server. 
+
+In the graph bellow, the blue route is the primary route, and green is secondary in case the primary route is down.
 
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