From 6d8f02d0d45e658ca7d102f4d28276ef4f033c27 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=D0=90=D0=BB=D0=B5=D0=BA=D1=81=D0=B5=D0=B9=20=D0=A1=D0=B0?=
 =?UTF-8?q?=D0=B1=D0=B8=D0=BB=D0=B8=D0=BD?= <aleksey@sabilin.com>
Date: Thu, 16 Jul 2026 20:52:31 +0300
Subject: [PATCH] fix(mnesia): add local ram_copies on joining nodes for
 verification/session.

Joining replicas hit already_exists without add_table_copy, so register/verify crashed with no_exists on node2. Refs EventHub/EventHubBack#30

Co-authored-by: Cursor <cursoragent@cursor.com>
---
 src/infra/infra_mnesia.erl | 22 ++++++++++++++++++++--
 1 file changed, 20 insertions(+), 2 deletions(-)

diff --git a/src/infra/infra_mnesia.erl b/src/infra/infra_mnesia.erl
index 8f05075..88ebbf2 100644
--- a/src/infra/infra_mnesia.erl
+++ b/src/infra/infra_mnesia.erl
@@ -24,6 +24,8 @@
 ]).
 
 -define(DISC_TABLES, ?TABLES -- [session, verification, admin_session, node_metric]).
+%% ram_copies: joining nodes must add_table_copy — create_table already_exists skips it.
+-define(RAM_TABLES, [session, verification, admin_session]).
 -define(TABLE_WAIT_TIMEOUT, 5000).
 -define(CLEANUP_INTERVAL, 30000). % 30 секунд
 
@@ -105,6 +107,7 @@ handle_call(init_tables, _From, State) ->
       ok = join_cluster(ExtraNodes)
   end,
   lists:foreach(fun create_table/1, ?TABLES),
+  lists:foreach(fun add_local_ram_copy/1, ?RAM_TABLES),
   % Принудительное создание node_metric на каждом узле
   case mnesia:create_table(node_metric, [
     {disc_copies, [node()]},     % хранить на диске
@@ -175,7 +178,8 @@ join_cluster(Nodes) ->
   mnesia:start(),
   ensure_schema_disc(),
   wait_for_tables_available(),
-  lists:foreach(fun add_local_disc_copy/1, ?DISC_TABLES).
+  lists:foreach(fun add_local_disc_copy/1, ?DISC_TABLES),
+  lists:foreach(fun add_local_ram_copy/1, ?RAM_TABLES).
 
 do_add_nodes(Nodes) ->
   ExtraNodes = application:get_env(eventhub, extra_db_nodes, []),
@@ -183,7 +187,8 @@ do_add_nodes(Nodes) ->
   {ok, _} = mnesia:change_config(extra_db_nodes, Nodes),
   ensure_schema_disc(),
   wait_for_tables_available(),
-  lists:foreach(fun add_local_disc_copy/1, ?DISC_TABLES).
+  lists:foreach(fun add_local_disc_copy/1, ?DISC_TABLES),
+  lists:foreach(fun add_local_ram_copy/1, ?RAM_TABLES).
 
 ensure_schema_disc() ->
   case lists:member(node(), mnesia:table_info(schema, disc_copies)) of
@@ -210,6 +215,19 @@ add_local_disc_copy(Tab) ->
     true -> ok
   end.
 
+add_local_ram_copy(Tab) ->
+  case lists:member(node(), mnesia:table_info(Tab, ram_copies)) of
+    false ->
+      io:format("Adding local ram copy of table ~p...~n", [Tab]),
+      case mnesia:add_table_copy(Tab, node(), ram_copies) of
+        {atomic, ok} -> ok;
+        {aborted, {already_exists, _}} -> ok;
+        {aborted, Reason} ->
+          io:format("Could not add ram copy for ~p: ~p~n", [Tab, Reason])
+      end;
+    true -> ok
+  end.
+
 wait_for_tables_available() ->
   lists:foreach(fun(Tab) -> wait_for_table(Tab) end, ?DISC_TABLES).