diff options
Diffstat (limited to 'lib/diameter/doc/src/diameter_app.xml')
| -rw-r--r-- | lib/diameter/doc/src/diameter_app.xml | 32 |
1 files changed, 20 insertions, 12 deletions
diff --git a/lib/diameter/doc/src/diameter_app.xml b/lib/diameter/doc/src/diameter_app.xml index d0f1b22ebd..d094e1bade 100644 --- a/lib/diameter/doc/src/diameter_app.xml +++ b/lib/diameter/doc/src/diameter_app.xml @@ -196,7 +196,8 @@ process.</p> </type> <desc> <p> -Invoked to signal the availability of a peer connection. +Invoked to signal the availability of a peer connection on the local +Erlang node. In particular, capabilities exchange with the peer has indicated support for the application in question, the RFC 3539 watchdog state machine for the connection has reached state <c>OKAY</c> and Diameter @@ -230,8 +231,8 @@ handled independently of &peer_up; and &peer_down;.</p> </type> <desc> <p> -Invoked to signal that a peer connection is no longer available -following a previous call to &peer_up;. +Invoked to signal that a peer connection on the local Erlang node is +no longer available following a previous call to &peer_up;. In particular, that the RFC 3539 watchdog state machine for the connection has left state <c>OKAY</c> and the peer will no longer be a candidate in &pick_peer; callbacks.</p> @@ -240,11 +241,11 @@ candidate in &pick_peer; callbacks.</p> </func> <func> -<name>Mod:pick_peer(Candidates, _Reserved, SvcName, State) +<name>Mod:pick_peer(LocalCandidates, RemoteCandidates, SvcName, State) -> Selection | false</name> <fsummary>Select a target peer for an outgoing request.</fsummary> <type> -<v>Candidates = [&peer;]</v> +<v>LocalCandidates = RemoteCandidates = [&peer;]</v> <v>SvcName = &mod_service_name;</v> <v>State = NewState = &state;</v> <v>Selection = {ok, Peer} | {Peer, NewState}</v> @@ -257,7 +258,7 @@ peer for an outgoing request. The return value indicates the selected peer.</p> <p> -The candidate list contains only those peers that have advertised +The candidate lists contain only those peers that have advertised support for the Diameter application in question during capabilities exchange, that have not be excluded by a <c>filter</c> option in the call to &mod_call; @@ -266,7 +267,11 @@ The order of the elements is unspecified except that any peers whose Origin-Host and Origin-Realm matches that of the outgoing request (in the sense of a <c>{filter, {all, [host, realm]}}</c> option to &mod_call;) -will be placed at the head of the list.</p> +will be placed at the head of the list. +<c>LocalCandidates</c> contains peers whose transport process resides +on the local Erlang node while +<c>RemoteCandidates</c> contains peers that have been communicated +from other nodes by services of the same name.</p> <p> A callback that returns a peer() will be followed by a @@ -286,16 +291,19 @@ retransmission to an alternate peer is abandoned if an answer is received from a previously selected peer.</p> <p> -Returning <c>false</c> or <c>{false, NewState}</c> causes <c>{error, -no_connection}</c> to be returned from &mod_call;.</p> - -<p> The return values <c>false</c> and <c>{false, State}</c> (that is, <c>NewState = State</c>) are equivalent, as are <c>{ok, Peer}</c> and <c>{Peer, State}</c>.</p> <note> <p> +<c>RemoteCandidates</c> is the empty list if the service has been +configured with the (default) &mod_service_opt; +<c>{use_shared_peers, false}</c>.</p> +</note> + +<warning> +<p> The return value <c>{Peer, NewState}</c> is only allowed if the Diameter application in question was configured with the &mod_application_opt; <c>{call_mutates_state, true}</c>. @@ -303,7 +311,7 @@ Otherwise, the <c>State</c> argument is always the intial value as configured on the application, not any subsequent value returned by a &peer_up; or &peer_down; callback.</p> -</note> +</warning> </desc> |