ovsdb: Introduce experimental support for clustered databases.

This commit adds support for OVSDB clustering via Raft.  Please read
ovsdb(7) for information on how to set up a clustered database.  It is
simple and boils down to running "ovsdb-tool create-cluster" on one server
and "ovsdb-tool join-cluster" on each of the others and then starting
ovsdb-server in the usual way on all of them.

One you have a clustered database, you configure ovn-controller and
ovn-northd to use it by pointing them to all of the servers, e.g. where
previously you might have said "tcp:1.2.3.4" was the database server,
now you say that it is "tcp:1.2.3.4,tcp:5.6.7.8,tcp:9.10.11.12".

This also adds support for database clustering to ovs-sandbox.

Acked-by: Justin Pettit <jpettit@ovn.org>
Tested-by: aginwala <aginwala@asu.edu>
Signed-off-by: Ben Pfaff <blp@ovn.org>

1 files changed, 29 insertions, 0 deletions

diff --git a/lib/jsonrpc.c b/lib/jsonrpc.c
index 036bdf469..f71026271 100644
--- a/lib/jsonrpc.c
+++ b/lib/jsonrpc.c
@@ -562,6 +562,16 @@ jsonrpc_create_error(struct json *error, const struct json *id)
                            json_clone(id));
 }
 
+struct jsonrpc_msg *
+jsonrpc_msg_clone(const struct jsonrpc_msg *old)
+{
+    return jsonrpc_create(old->type, old->method,
+                          json_nullable_clone(old->params),
+                          json_nullable_clone(old->result),
+                          json_nullable_clone(old->error),
+                          json_nullable_clone(old->id));
+}
+
 const char *
 jsonrpc_msg_type_to_string(enum jsonrpc_msg_type type)
 {
@@ -753,6 +763,16 @@ jsonrpc_msg_to_json(struct jsonrpc_msg *m)
 
     return json;
 }
+
+char *
+jsonrpc_msg_to_string(const struct jsonrpc_msg *m)
+{
+    struct jsonrpc_msg *copy = jsonrpc_msg_clone(m);
+    struct json *json = jsonrpc_msg_to_json(copy);
+    char *s = json_to_string(json, JSSF_SORT);
+    json_destroy(json);
+    return s;
+}
 
 /* A JSON-RPC session with reconnection. */
 
@@ -877,6 +897,15 @@ jsonrpc_session_close(struct jsonrpc_session *s)
     }
 }
 
+struct jsonrpc *
+jsonrpc_session_steal(struct jsonrpc_session *s)
+{
+    struct jsonrpc *rpc = s->rpc;
+    s->rpc = NULL;
+    jsonrpc_session_close(s);
+    return rpc;
+}
+
 static void
 jsonrpc_session_disconnect(struct jsonrpc_session *s)
 {