jsonrpc: Allow jsonrpc_session to have more than one remote.

The implementation cycles through the remotes in random order.  This allows
clients to perform some load balancing across alternative implementations
of a service.

Signed-off-by: Ben Pfaff <blp@ovn.org>
Acked-by: Russell Bryant <russell@ovn.org>
Acked-by: Justin Pettit <jpettit@ovn.org>

1 files changed, 5 insertions, 1 deletions

diff --git a/lib/jsonrpc.h b/lib/jsonrpc.h
index 9b4fb0e51..969a6ed38 100644
--- a/lib/jsonrpc.h
+++ b/lib/jsonrpc.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2009, 2010, 2012, 2013 Nicira, Inc.
+ * Copyright (c) 2009, 2010, 2012, 2013, 2017 Nicira, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -29,6 +29,7 @@ struct jsonrpc_msg;
 struct pstream;
 struct reconnect_stats;
 struct stream;
+struct svec;
 
 /* API for a JSON-RPC stream. */
 
@@ -99,6 +100,8 @@ struct json *jsonrpc_msg_to_json(struct jsonrpc_msg *);
 /* A JSON-RPC session with reconnection. */
 
 struct jsonrpc_session *jsonrpc_session_open(const char *name, bool retry);
+struct jsonrpc_session *jsonrpc_session_open_multiple(const struct svec *,
+                                                      bool retry);
 struct jsonrpc_session *jsonrpc_session_open_unreliably(struct jsonrpc *,
                                                         uint8_t);
 void jsonrpc_session_close(struct jsonrpc_session *);
@@ -108,6 +111,7 @@ void jsonrpc_session_wait(struct jsonrpc_session *);
 
 size_t jsonrpc_session_get_backlog(const struct jsonrpc_session *);
 const char *jsonrpc_session_get_name(const struct jsonrpc_session *);
+size_t jsonrpc_session_get_n_remotes(const struct jsonrpc_session *);
 
 int jsonrpc_session_send(struct jsonrpc_session *, struct jsonrpc_msg *);
 struct jsonrpc_msg *jsonrpc_session_recv(struct jsonrpc_session *);