reset before changing node type

Matthias points out that the only way for mnesia:change_config to
start creating tables is for the node to re-join the cluster (and get
its old table definitions from other nodes).  Instead of fixing the
tables after that, we now reset inside the cluster command.  Note that
in very old rabbit versions, we'd just prevent this by having the user
reset manually.

2 files changed, 24 insertions, 37 deletions

diff --git a/src/rabbit_mnesia.erl b/src/rabbit_mnesia.erl
index 805b415200..6b901eaecc 100644
--- a/src/rabbit_mnesia.erl
+++ b/src/rabbit_mnesia.erl
@@ -117,6 +117,22 @@ force_cluster(ClusterNodes) ->
 cluster(ClusterNodes, Force) ->
     ensure_mnesia_not_running(),
     ensure_mnesia_dir(),
+
+    %% Reset the node if we're in a cluster and have just changed node type
+    rabbit_misc:ensure_ok(mnesia:start(), cannot_start_mnesia),
+    AllClusteredNodes =
+        lists:usort(all_clustered_nodes() ++
+                        read_cluster_nodes_config()) -- [node()],
+    mnesia:stop(),
+    case {AllClusteredNodes =/= [],
+          is_disc_node() =/= should_be_disc_node(ClusterNodes)} of
+        {true, true} -> error_logger:warning_msg("changing node type; "
+                                                 "resetting...~n"),
+                        reset();
+        {_, _}       -> ok
+    end,
+
+    %% Join the cluster
     rabbit_misc:ensure_ok(mnesia:start(), cannot_start_mnesia),
     try
         ok = init_db(ClusterNodes, Force,
@@ -431,7 +447,7 @@ delete_previously_running_nodes() ->
 init_db(ClusterNodes, Force, SecondaryPostMnesiaFun) ->
     UClusterNodes = lists:usort(ClusterNodes),
     ProperClusterNodes = UClusterNodes -- [node()],
-    IsDiskNode = ClusterNodes == [] orelse lists:member(node(), ClusterNodes),
+    IsDiskNode = should_be_disc_node(ClusterNodes),
     WasDiskNode = is_disc_node(),
     case mnesia:change_config(extra_db_nodes, ProperClusterNodes) of
         {ok, Nodes} ->
@@ -480,7 +496,6 @@ init_db(ClusterNodes, Force, SecondaryPostMnesiaFun) ->
                             false -> {ram, ram_copies}
                         end,
                     ok = wait_for_replicated_tables(),
-                    assert_tables_copy_type(CopyTypeAlt),
                     ok = create_local_table_copy(schema, CopyTypeAlt),
                     ok = create_local_table_copies(CopyType),
                     ok = SecondaryPostMnesiaFun(),
@@ -549,6 +564,9 @@ is_disc_node() ->
     %% disc node).
     filelib:is_regular(filename:join(dir(), "rabbit_durable_exchange.DCD")).
 
+should_be_disc_node(ClusterNodes) ->
+    ClusterNodes == [] orelse lists:member(node(), ClusterNodes).
+
 move_db() ->
     mnesia:stop(),
     MnesiaDir = filename:dirname(dir() ++ "/"),
@@ -612,41 +630,6 @@ copy_type_to_ram(TabDef) ->
 table_has_copy_type(TabDef, DiscType) ->
     lists:member(node(), proplists:get_value(DiscType, TabDef, [])).
 
-assert_tables_copy_type(CopyTypeAlt) ->
-    case mnesia:table_info(schema, storage_type) of
-        CopyTypeAlt -> ok;
-        _ -> case mnesia:change_table_copy_type(schema, node(), CopyTypeAlt) of
-                 {aborted, {"Disc resident tables", _, _}} -> ok;
-                 {atomic, ok} -> ok;
-                 E -> exit({'node_conversion_failed', E})
-             end
-    end,
-    lists:foreach(
-      fun({Tab, TabDef}) ->
-              HasDiscCopies     = table_has_copy_type(TabDef, disc_copies),
-              HasDiscOnlyCopies = table_has_copy_type(TabDef, disc_only_copies),
-              StorageType = if HasDiscCopies     -> disc_copies;
-                               HasDiscOnlyCopies -> disc_only_copies;
-                               true              -> ram_copies
-                            end,
-              StorageType1 = if CopyTypeAlt =:= disc_copies -> StorageType;
-                                true                        -> ram_copies
-                             end,
-              case mnesia:table_info(Tab, storage_type) of
-                  StorageType1 -> ok;
-                  unknown      -> ok;
-                  _            ->
-                      {atomic, ok} = mnesia:change_table_copy_type(
-                                       Tab, node(), StorageType1)
-              end
-      end, table_definitions()),
-    case mnesia:table_info(schema, storage_type) of
-        CopyTypeAlt -> ok;
-        _           ->
-            {atomic, ok} = mnesia:change_table_copy_type(
-                             schema, node(), CopyTypeAlt)
-    end.
-
 create_local_table_copies(Type) ->
     lists:foreach(
       fun ({Tab, TabDef}) ->
diff --git a/src/rabbit_tests.erl b/src/rabbit_tests.erl
index af20112068..0c1a04b274 100644
--- a/src/rabbit_tests.erl
+++ b/src/rabbit_tests.erl
@@ -1066,6 +1066,10 @@ test_cluster_management2(SecondaryNode) ->
     {error, {no_running_cluster_nodes, _, _}} =
         control_action(reset, []),
 
+    %% attempt to change type when no other node is alive
+    {error, {no_running_cluster_nodes, _, _}} =
+        control_action(cluster, [SecondaryNodeS]),
+
     %% leave system clustered, with the secondary node as a ram node
     ok = control_action(force_reset, []),
     ok = control_action(start_app, []),