Mnesia migrations with global lock on startup. Refs EventHub/EventHubBack#24

This commit is contained in:
2026-07-07 17:54:29 +03:00
parent 6e1157134c
commit 7c5f2d26b8
5 changed files with 806 additions and 647 deletions
+270 -272
View File
@@ -1,273 +1,271 @@
%% ===================================================================
%% EventHub infra_mnesia (финальная версия с автоочисткой кластера)
%% ===================================================================
-module(infra_mnesia).
-behaviour(gen_server).
-include("records.hrl").
-export([start_link/0, init_tables/0, wait_for_tables/0, wait_for_table/1]).
-export([add_cluster_nodes/1]).
-export([init/1, handle_call/3, handle_cast/2, handle_info/2,
terminate/2, code_change/3]).
-define(TABLES, [
user, session, verification, admin, admin_session, auth_session,
calendar, calendar_share, calendar_specialist,
event, recurrence_exception,
booking,
review, report, banned_word,
ticket, subscription,
admin_audit, notification,
stats, node_metric, schema_migration
]).
-define(DISC_TABLES, ?TABLES -- [session, verification, admin_session, node_metric]).
-define(TABLE_WAIT_TIMEOUT, 5000).
-define(CLEANUP_INTERVAL, 30000). % 30 секунд
%% ===================================================================
%% API
%% ===================================================================
start_link() ->
% Счётчики для метрик (сессии, ws-соединения)
ets:new(eventhub_counters, [named_table, public, set, {write_concurrency, true}]),
gen_server:start_link({local, ?MODULE}, ?MODULE, [], []).
init_tables() ->
gen_server:call(?MODULE, init_tables).
wait_for_tables() ->
gen_server:call(?MODULE, wait_for_tables).
add_cluster_nodes(Nodes) ->
gen_server:call(?MODULE, {add_nodes, Nodes}).
%% ===================================================================
%% gen_server callbacks
%% ===================================================================
init([]) ->
{ok, #{}}.
handle_call(init_tables, _From, State) ->
ExtraNodes = application:get_env(eventhub, extra_db_nodes, []),
case ExtraNodes of
[] ->
ok = maybe_recreate_schema();
%% ok = migration_engine:init_migrations_table(),
%% _ = migration_engine:apply_pending(); //todo выключил - обваливает кластер, нужно разбираться
_ ->
ok = join_cluster(ExtraNodes)
end,
lists:foreach(fun create_table/1, ?TABLES),
% Принудительное создание node_metric на каждом узле
case mnesia:create_table(node_metric, [
{disc_copies, [node()]}, % хранить на диске
{local_content, true}, % не реплицировать
{attributes, record_info(fields, node_metric)}
]) of
{atomic, ok} -> ok;
{aborted, {already_exists, node_metric}} -> ok;
_ -> ok
end,
% ГАРАНТИРУЕМ, что узел имеет локальную копию node_metric (критично для присоединяющихся узлов)
case lists:member(node(), mnesia:table_info(node_metric, disc_copies) ++
mnesia:table_info(node_metric, ram_copies)) of
false -> mnesia:add_table_copy(node_metric, node(), disc_copies);
true -> ok
end,
ok = create_indices(),
ok = stats_collector:subscribe(),
ok = start_cleanup_timer(),
{reply, ok, State};
handle_call({add_nodes, Nodes}, _From, State) ->
ok = do_add_nodes(Nodes),
{reply, ok, State};
handle_call(wait_for_tables, _From, State) ->
mnesia:wait_for_tables(?TABLES, ?TABLE_WAIT_TIMEOUT),
{reply, ok, State}.
handle_cast(_Msg, State) -> {noreply, State}.
handle_info({cleanup}, State) ->
prune_dead_nodes(),
erlang:send_after(?CLEANUP_INTERVAL, self(), {cleanup}),
{noreply, State};
handle_info(_Info, State) -> {noreply, State}.
terminate(_Reason, _State) -> ok.
code_change(_OldVsn, State, _Extra) -> {ok, State}.
%% ===================================================================
%% Управление схемой
%% ===================================================================
maybe_recreate_schema() ->
MnesiaDir = mnesia:system_info(directory),
case filelib:is_dir(MnesiaDir) of
false ->
io:format("Mnesia directory (~s) not found. Creating fresh schema...~n", [MnesiaDir]),
mnesia:stop(),
mnesia:delete_schema([node()]),
mnesia:create_schema([node()]),
mnesia:start(),
ok;
true ->
io:format("Mnesia directory exists (~s). Reusing existing schema.~n", [MnesiaDir]),
case mnesia:system_info(is_running) of
yes -> ok;
_ -> mnesia:start()
end
end.
join_cluster(Nodes) ->
case mnesia:system_info(is_running) of
yes -> mnesia:stop();
no -> ok
end,
application:set_env(mnesia, extra_db_nodes, Nodes),
mnesia:start(),
ensure_schema_disc(),
wait_for_tables_available(),
lists:foreach(fun add_local_disc_copy/1, ?DISC_TABLES).
do_add_nodes(Nodes) ->
ExtraNodes = application:get_env(eventhub, extra_db_nodes, []),
application:set_env(eventhub, extra_db_nodes, Nodes ++ ExtraNodes),
{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).
ensure_schema_disc() ->
case lists:member(node(), mnesia:table_info(schema, disc_copies)) of
false ->
io:format("Changing schema copy to disc...~n"),
case mnesia:change_table_copy_type(schema, node(), disc_copies) of
{atomic, ok} -> ok;
{aborted, {already_exists, _, _}} -> ok;
{aborted, Reason} -> error({failed_schema_disc, Reason})
end;
true -> ok
end.
add_local_disc_copy(Tab) ->
case lists:member(node(), mnesia:table_info(Tab, disc_copies)) of
false ->
io:format("Adding local disc copy of table ~p...~n", [Tab]),
case mnesia:add_table_copy(Tab, node(), disc_copies) of
{atomic, ok} -> ok;
{aborted, {already_exists, _}} -> ok;
{aborted, Reason} ->
io:format("Could not add disc 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).
wait_for_table(Tab) ->
case lists:member(Tab, mnesia:system_info(tables)) of
true -> ok;
false ->
timer:sleep(100),
wait_for_table(Tab)
end.
%% ===================================================================
%% Автоматическая очистка мёртвых узлов
%% ===================================================================
start_cleanup_timer() ->
erlang:send_after(?CLEANUP_INTERVAL, self(), {cleanup}),
ok.
prune_dead_nodes() ->
AliveNodes = lists:filter(fun(Node) ->
Node =/= node() andalso net_adm:ping(Node) =:= pong
end, mnesia:system_info(db_nodes)),
DeadNodes = mnesia:system_info(db_nodes) -- [node() | AliveNodes],
lists:foreach(fun(Node) ->
io:format("Removing dead node ~p from Mnesia schema...~n", [Node]),
lists:foreach(fun(Tab) ->
case lists:member(Node, mnesia:table_info(Tab, disc_copies)) of
true -> catch mnesia:del_table_copy(Tab, Node);
false -> ok
end
end, ?DISC_TABLES),
catch mnesia:del_table_copy(schema, Node)
end, DeadNodes).
%% ===================================================================
%% Создание / открытие таблиц
%% ===================================================================
create_table(Table) ->
Opts = table_opts(Table),
case mnesia:create_table(Table, Opts) of
{atomic, ok} -> ok;
{aborted, {already_exists, _}} -> ok;
{aborted, Reason} ->
error({table_creation_failed, Table, Reason})
end.
%% ===================================================================
%% Опции хранения таблиц
%% ===================================================================
table_opts(user) -> [{disc_copies, [node()]}, {attributes, record_info(fields, user)}];
table_opts(admin) -> [{disc_copies, [node()]}, {attributes, record_info(fields, admin)}];
table_opts(calendar) -> [{disc_copies, [node()]}, {attributes, record_info(fields, calendar)}];
table_opts(calendar_share) -> [{disc_copies, [node()]}, {attributes, record_info(fields, calendar_share)}];
table_opts(calendar_specialist) -> [{disc_copies, [node()]}, {attributes, record_info(fields, calendar_specialist)}];
table_opts(event) -> [{disc_copies, [node()]}, {attributes, record_info(fields, event)}];
table_opts(recurrence_exception) -> [{disc_copies, [node()]}, {attributes, record_info(fields, recurrence_exception)}];
table_opts(booking) -> [{disc_copies, [node()]}, {attributes, record_info(fields, booking)}];
table_opts(review) -> [{disc_copies, [node()]}, {attributes, record_info(fields, review)}];
table_opts(report) -> [{disc_copies, [node()]}, {attributes, record_info(fields, report)}];
table_opts(banned_word) -> [{disc_copies, [node()]}, {attributes, record_info(fields, banned_word)}];
table_opts(ticket) -> [{disc_copies, [node()]}, {attributes, record_info(fields, ticket)}];
table_opts(subscription) -> [{disc_copies, [node()]}, {attributes, record_info(fields, subscription)}];
table_opts(admin_audit) -> [{disc_copies, [node()]}, {attributes, record_info(fields, admin_audit)}];
table_opts(notification) -> [{disc_copies, [node()]}, {attributes, record_info(fields, notification)}];
table_opts(stats) -> [{disc_copies, [node()]}, {attributes, record_info(fields, stats)}];
table_opts(schema_migration) -> [{disc_copies, [node()]}, {attributes, record_info(fields, schema_migration)}];
table_opts(session) -> [{ram_copies, [node()]}, {attributes, record_info(fields, session)}];
table_opts(verification) -> [{ram_copies, [node()]}, {attributes, record_info(fields, verification)}];
table_opts(admin_session) -> [{ram_copies, [node()]}, {attributes, record_info(fields, admin_session)}];
table_opts(auth_session) -> [{disc_copies, [node()]}, {attributes, record_info(fields, auth_session)}];
table_opts(node_metric) -> [{disc_copies, [node()]}, {local_content, true}, {attributes, record_info(fields, node_metric)}].
%% ===================================================================
%% Индексы
%% ===================================================================
create_indices() ->
mnesia:add_table_index(event, calendar_id),
mnesia:add_table_index(event, title),
mnesia:add_table_index(event, created_at),
mnesia:add_table_index(event, start_time),
mnesia:add_table_index(event, event_type),
mnesia:add_table_index(event, master_id),
mnesia:add_table_index(event, specialist_id),
mnesia:add_table_index(event, status),
mnesia:add_table_index(booking, event_id),
mnesia:add_table_index(booking, user_id),
mnesia:add_table_index(booking, status),
mnesia:add_table_index(calendar, owner_id),
mnesia:add_table_index(calendar, status),
mnesia:add_table_index(calendar, short_name),
mnesia:add_table_index(calendar, category),
mnesia:add_table_index(calendar_specialist, calendar_id),
mnesia:add_table_index(calendar_specialist, user_id),
mnesia:add_table_index(user, nickname),
mnesia:add_table_index(user, email),
mnesia:add_table_index(notification, user_id),
mnesia:add_table_index(notification, is_read),
mnesia:add_table_index(auth_session, family_id),
mnesia:add_table_index(auth_session, subject_id),
%% ===================================================================
%% EventHub infra_mnesia (финальная версия с автоочисткой кластера)
%% ===================================================================
-module(infra_mnesia).
-behaviour(gen_server).
-include("records.hrl").
-export([start_link/0, init_tables/0, wait_for_tables/0, wait_for_table/1]).
-export([add_cluster_nodes/1]).
-export([init/1, handle_call/3, handle_cast/2, handle_info/2,
terminate/2, code_change/3]).
-define(TABLES, [
user, session, verification, admin, admin_session, auth_session,
calendar, calendar_share, calendar_specialist,
event, recurrence_exception,
booking,
review, report, banned_word,
ticket, subscription,
admin_audit, notification,
stats, node_metric, schema_migration
]).
-define(DISC_TABLES, ?TABLES -- [session, verification, admin_session, node_metric]).
-define(TABLE_WAIT_TIMEOUT, 5000).
-define(CLEANUP_INTERVAL, 30000). % 30 секунд
%% ===================================================================
%% API
%% ===================================================================
start_link() ->
% Счётчики для метрик (сессии, ws-соединения)
ets:new(eventhub_counters, [named_table, public, set, {write_concurrency, true}]),
gen_server:start_link({local, ?MODULE}, ?MODULE, [], []).
init_tables() ->
gen_server:call(?MODULE, init_tables).
wait_for_tables() ->
gen_server:call(?MODULE, wait_for_tables).
add_cluster_nodes(Nodes) ->
gen_server:call(?MODULE, {add_nodes, Nodes}).
%% ===================================================================
%% gen_server callbacks
%% ===================================================================
init([]) ->
{ok, #{}}.
handle_call(init_tables, _From, State) ->
ExtraNodes = application:get_env(eventhub, extra_db_nodes, []),
case ExtraNodes of
[] ->
ok = maybe_recreate_schema();
_ ->
ok = join_cluster(ExtraNodes)
end,
lists:foreach(fun create_table/1, ?TABLES),
% Принудительное создание node_metric на каждом узле
case mnesia:create_table(node_metric, [
{disc_copies, [node()]}, % хранить на диске
{local_content, true}, % не реплицировать
{attributes, record_info(fields, node_metric)}
]) of
{atomic, ok} -> ok;
{aborted, {already_exists, node_metric}} -> ok;
_ -> ok
end,
% ГАРАНТИРУЕМ, что узел имеет локальную копию node_metric (критично для присоединяющихся узлов)
case lists:member(node(), mnesia:table_info(node_metric, disc_copies) ++
mnesia:table_info(node_metric, ram_copies)) of
false -> mnesia:add_table_copy(node_metric, node(), disc_copies);
true -> ok
end,
ok = create_indices(),
ok = stats_collector:subscribe(),
ok = start_cleanup_timer(),
{reply, ok, State};
handle_call({add_nodes, Nodes}, _From, State) ->
ok = do_add_nodes(Nodes),
{reply, ok, State};
handle_call(wait_for_tables, _From, State) ->
mnesia:wait_for_tables(?TABLES, ?TABLE_WAIT_TIMEOUT),
{reply, ok, State}.
handle_cast(_Msg, State) -> {noreply, State}.
handle_info({cleanup}, State) ->
prune_dead_nodes(),
erlang:send_after(?CLEANUP_INTERVAL, self(), {cleanup}),
{noreply, State};
handle_info(_Info, State) -> {noreply, State}.
terminate(_Reason, _State) -> ok.
code_change(_OldVsn, State, _Extra) -> {ok, State}.
%% ===================================================================
%% Управление схемой
%% ===================================================================
maybe_recreate_schema() ->
MnesiaDir = mnesia:system_info(directory),
case filelib:is_dir(MnesiaDir) of
false ->
io:format("Mnesia directory (~s) not found. Creating fresh schema...~n", [MnesiaDir]),
mnesia:stop(),
mnesia:delete_schema([node()]),
mnesia:create_schema([node()]),
mnesia:start(),
ok;
true ->
io:format("Mnesia directory exists (~s). Reusing existing schema.~n", [MnesiaDir]),
case mnesia:system_info(is_running) of
yes -> ok;
_ -> mnesia:start()
end
end.
join_cluster(Nodes) ->
case mnesia:system_info(is_running) of
yes -> mnesia:stop();
no -> ok
end,
application:set_env(mnesia, extra_db_nodes, Nodes),
mnesia:start(),
ensure_schema_disc(),
wait_for_tables_available(),
lists:foreach(fun add_local_disc_copy/1, ?DISC_TABLES).
do_add_nodes(Nodes) ->
ExtraNodes = application:get_env(eventhub, extra_db_nodes, []),
application:set_env(eventhub, extra_db_nodes, Nodes ++ ExtraNodes),
{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).
ensure_schema_disc() ->
case lists:member(node(), mnesia:table_info(schema, disc_copies)) of
false ->
io:format("Changing schema copy to disc...~n"),
case mnesia:change_table_copy_type(schema, node(), disc_copies) of
{atomic, ok} -> ok;
{aborted, {already_exists, _, _}} -> ok;
{aborted, Reason} -> error({failed_schema_disc, Reason})
end;
true -> ok
end.
add_local_disc_copy(Tab) ->
case lists:member(node(), mnesia:table_info(Tab, disc_copies)) of
false ->
io:format("Adding local disc copy of table ~p...~n", [Tab]),
case mnesia:add_table_copy(Tab, node(), disc_copies) of
{atomic, ok} -> ok;
{aborted, {already_exists, _}} -> ok;
{aborted, Reason} ->
io:format("Could not add disc 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).
wait_for_table(Tab) ->
case lists:member(Tab, mnesia:system_info(tables)) of
true -> ok;
false ->
timer:sleep(100),
wait_for_table(Tab)
end.
%% ===================================================================
%% Автоматическая очистка мёртвых узлов
%% ===================================================================
start_cleanup_timer() ->
erlang:send_after(?CLEANUP_INTERVAL, self(), {cleanup}),
ok.
prune_dead_nodes() ->
AliveNodes = lists:filter(fun(Node) ->
Node =/= node() andalso net_adm:ping(Node) =:= pong
end, mnesia:system_info(db_nodes)),
DeadNodes = mnesia:system_info(db_nodes) -- [node() | AliveNodes],
lists:foreach(fun(Node) ->
io:format("Removing dead node ~p from Mnesia schema...~n", [Node]),
lists:foreach(fun(Tab) ->
case lists:member(Node, mnesia:table_info(Tab, disc_copies)) of
true -> catch mnesia:del_table_copy(Tab, Node);
false -> ok
end
end, ?DISC_TABLES),
catch mnesia:del_table_copy(schema, Node)
end, DeadNodes).
%% ===================================================================
%% Создание / открытие таблиц
%% ===================================================================
create_table(Table) ->
Opts = table_opts(Table),
case mnesia:create_table(Table, Opts) of
{atomic, ok} -> ok;
{aborted, {already_exists, _}} -> ok;
{aborted, Reason} ->
error({table_creation_failed, Table, Reason})
end.
%% ===================================================================
%% Опции хранения таблиц
%% ===================================================================
table_opts(user) -> [{disc_copies, [node()]}, {attributes, record_info(fields, user)}];
table_opts(admin) -> [{disc_copies, [node()]}, {attributes, record_info(fields, admin)}];
table_opts(calendar) -> [{disc_copies, [node()]}, {attributes, record_info(fields, calendar)}];
table_opts(calendar_share) -> [{disc_copies, [node()]}, {attributes, record_info(fields, calendar_share)}];
table_opts(calendar_specialist) -> [{disc_copies, [node()]}, {attributes, record_info(fields, calendar_specialist)}];
table_opts(event) -> [{disc_copies, [node()]}, {attributes, record_info(fields, event)}];
table_opts(recurrence_exception) -> [{disc_copies, [node()]}, {attributes, record_info(fields, recurrence_exception)}];
table_opts(booking) -> [{disc_copies, [node()]}, {attributes, record_info(fields, booking)}];
table_opts(review) -> [{disc_copies, [node()]}, {attributes, record_info(fields, review)}];
table_opts(report) -> [{disc_copies, [node()]}, {attributes, record_info(fields, report)}];
table_opts(banned_word) -> [{disc_copies, [node()]}, {attributes, record_info(fields, banned_word)}];
table_opts(ticket) -> [{disc_copies, [node()]}, {attributes, record_info(fields, ticket)}];
table_opts(subscription) -> [{disc_copies, [node()]}, {attributes, record_info(fields, subscription)}];
table_opts(admin_audit) -> [{disc_copies, [node()]}, {attributes, record_info(fields, admin_audit)}];
table_opts(notification) -> [{disc_copies, [node()]}, {attributes, record_info(fields, notification)}];
table_opts(stats) -> [{disc_copies, [node()]}, {attributes, record_info(fields, stats)}];
table_opts(schema_migration) -> [{disc_copies, [node()]}, {attributes, record_info(fields, schema_migration)}];
table_opts(session) -> [{ram_copies, [node()]}, {attributes, record_info(fields, session)}];
table_opts(verification) -> [{ram_copies, [node()]}, {attributes, record_info(fields, verification)}];
table_opts(admin_session) -> [{ram_copies, [node()]}, {attributes, record_info(fields, admin_session)}];
table_opts(auth_session) -> [{disc_copies, [node()]}, {attributes, record_info(fields, auth_session)}];
table_opts(node_metric) -> [{disc_copies, [node()]}, {local_content, true}, {attributes, record_info(fields, node_metric)}].
%% ===================================================================
%% Индексы
%% ===================================================================
create_indices() ->
mnesia:add_table_index(event, calendar_id),
mnesia:add_table_index(event, title),
mnesia:add_table_index(event, created_at),
mnesia:add_table_index(event, start_time),
mnesia:add_table_index(event, event_type),
mnesia:add_table_index(event, master_id),
mnesia:add_table_index(event, specialist_id),
mnesia:add_table_index(event, status),
mnesia:add_table_index(booking, event_id),
mnesia:add_table_index(booking, user_id),
mnesia:add_table_index(booking, status),
mnesia:add_table_index(calendar, owner_id),
mnesia:add_table_index(calendar, status),
mnesia:add_table_index(calendar, short_name),
mnesia:add_table_index(calendar, category),
mnesia:add_table_index(calendar_specialist, calendar_id),
mnesia:add_table_index(calendar_specialist, user_id),
mnesia:add_table_index(user, nickname),
mnesia:add_table_index(user, email),
mnesia:add_table_index(notification, user_id),
mnesia:add_table_index(notification, is_read),
mnesia:add_table_index(auth_session, family_id),
mnesia:add_table_index(auth_session, subject_id),
ok.
+198 -121
View File
@@ -1,121 +1,198 @@
-module(migration_engine).
-behaviour(gen_server).
-include("records.hrl").
%% API
-export([start_link/0, init_migrations_table/0, apply_pending/0,
rollback/1, status/0]).
%% gen_server callbacks
-export([init/1, handle_call/3, handle_cast/2, handle_info/2,
terminate/2, code_change/3]).
-define(TABLE, schema_migration).
%% ------------------------------
%% API
%% ------------------------------
start_link() ->
gen_server:start_link({local, ?MODULE}, ?MODULE, [], []).
init_migrations_table() ->
gen_server:call(?MODULE, init_table).
apply_pending() ->
gen_server:call(?MODULE, apply_pending).
rollback(Version) ->
gen_server:call(?MODULE, {rollback, Version}).
status() ->
gen_server:call(?MODULE, status).
%% ------------------------------
%% gen_server callbacks
%% ------------------------------
init([]) ->
{ok, #{}}.
handle_call(init_table, _From, State) ->
case lists:member(?TABLE, mnesia:system_info(tables)) of
true -> ok;
false ->
mnesia:create_table(?TABLE, [
{disc_copies, [node()]},
{attributes, record_info(fields, schema_migration)},
{type, set}
])
end,
infra_mnesia:wait_for_table(?TABLE),
{reply, ok, State};
handle_call(apply_pending, _From, State) ->
Result = do_apply_pending(),
{reply, Result, State};
handle_call({rollback, Version}, _From, State) ->
Result = do_rollback(Version),
{reply, Result, State};
handle_call(status, _From, State) ->
Applied = applied_versions(),
Pending = pending_versions() -- Applied,
{reply, #{applied => lists:map(fun atom_to_list/1, Applied),
pending => lists:map(fun atom_to_list/1, Pending)}, State}.
handle_cast(_Msg, State) -> {noreply, State}.
handle_info(_Msg, State) -> {noreply, State}.
terminate(_Reason, _State) -> ok.
code_change(_OldVsn, State, _Extra) -> {ok, State}.
%% ------------------------------
%% Внутренняя логика
%% ------------------------------
do_apply_pending() ->
Pending = pending_versions() -- applied_versions(),
lists:foreach(fun(Module) -> code:ensure_loaded(Module) end, Pending),
lists:foldl(fun(Version, Acc) ->
try Version:up() of
_ -> mark_applied(Version), Acc
catch _:Reason ->
[{error, atom_to_list(Version), Reason} | Acc]
end
end, [], Pending).
do_rollback(TargetStr) ->
Target = list_to_atom(TargetStr),
Applied = applied_versions(),
ToRollback = lists:sort(fun(A,B) -> A > B end,
[V || V <- Applied, V > Target]),
lists:foreach(fun(Version) ->
code:ensure_loaded(Version),
try Version:down() of
_ -> unmark_applied(Version)
catch _:Reason ->
throw({rollback_failed, atom_to_list(Version), Reason})
end
end, ToRollback).
applied_versions() ->
[list_to_atom(V) || #schema_migration{version = V} <-
mnesia:dirty_match_object(#schema_migration{_ = '_'})].
pending_versions() ->
AllMods = code:all_available(),
[list_to_atom(Module) || Module <- extract_module_names(AllMods), lists:prefix("20", Module)].
extract_module_names(ModInfoList) ->
[Name || {Name, _, _} <- ModInfoList].
mark_applied(Version) ->
mnesia:dirty_write(#schema_migration{
version = atom_to_list(Version),
applied_at = calendar:local_time()
}).
unmark_applied(Version) ->
mnesia:dirty_delete({?TABLE, atom_to_list(Version)}).
-module(migration_engine).
-behaviour(gen_server).
-include("records.hrl").
%% API
-export([start_link/0, ensure_applied/0, apply_pending/0,
rollback/1, status/0]).
%% gen_server callbacks
-export([init/1, handle_call/3, handle_cast/2, handle_info/2,
terminate/2, code_change/3]).
-define(TABLE, schema_migration).
-define(LOCK_VERSION, "__migration_lock__").
-define(LOCK_STALE_SECONDS, 300).
-define(WAIT_TIMEOUT_MS, 120000).
-define(WAIT_INTERVAL_MS, 200).
%% Упорядоченный реестр миграций (добавлять новые модули в конец списка).
-define(ALL_MIGRATIONS, [
'20260501120000_base_schema',
'20260504150000_test_migration'
]).
%% ------------------------------
%% API
%% ------------------------------
start_link() ->
gen_server:start_link({local, ?MODULE}, ?MODULE, [], []).
%% @doc Безопасно применить pending-миграции при старте (с global lock в Mnesia).
-spec ensure_applied() -> ok | {error, term()}.
ensure_applied() ->
gen_server:call(?MODULE, ensure_applied, infinity).
apply_pending() ->
gen_server:call(?MODULE, apply_pending).
rollback(Version) ->
gen_server:call(?MODULE, {rollback, Version}).
status() ->
gen_server:call(?MODULE, status).
%% ------------------------------
%% gen_server callbacks
%% ------------------------------
init([]) ->
{ok, #{}}.
handle_call(ensure_applied, _From, State) ->
Result = do_ensure_applied(),
{reply, Result, State};
handle_call(apply_pending, _From, State) ->
Result = do_apply_pending(),
{reply, Result, State};
handle_call({rollback, Version}, _From, State) ->
Result = do_rollback(Version),
{reply, Result, State};
handle_call(status, _From, State) ->
Applied = applied_versions(),
Pending = pending_versions() -- Applied,
{reply, #{applied => [atom_to_list(V) || V <- Applied],
pending => [atom_to_list(V) || V <- Pending]}, State}.
handle_cast(_Msg, State) -> {noreply, State}.
handle_info(_Msg, State) -> {noreply, State}.
terminate(_Reason, _State) -> ok.
code_change(_OldVsn, State, _Extra) -> {ok, State}.
%% ------------------------------
%% Координация при старте
%% ------------------------------
do_ensure_applied() ->
case all_applied() of
true -> ok;
false ->
case acquire_lock() of
ok ->
try
case do_apply_pending() of
ok -> ok;
{error, Reason} -> {error, Reason}
end
after
release_lock()
end;
{error, locked} ->
wait_until_applied(?WAIT_TIMEOUT_MS)
end
end.
all_applied() ->
pending_versions() -- applied_versions() =:= [].
wait_until_applied(TimeoutMs) when TimeoutMs =< 0 ->
{error, migration_timeout};
wait_until_applied(TimeoutMs) ->
case all_applied() of
true -> ok;
false ->
timer:sleep(?WAIT_INTERVAL_MS),
wait_until_applied(TimeoutMs - ?WAIT_INTERVAL_MS)
end.
acquire_lock() ->
Now = calendar:universal_time(),
case mnesia:sync_transaction(fun() -> try_acquire_lock(Now) end) of
{atomic, ok} -> ok;
{aborted, locked} -> {error, locked};
{aborted, Reason} -> {error, Reason}
end.
try_acquire_lock(Now) ->
case mnesia:read(?TABLE, ?LOCK_VERSION, read) of
[] ->
mnesia:write(#schema_migration{version = ?LOCK_VERSION, applied_at = Now}),
ok;
[#schema_migration{applied_at = At}] ->
case lock_stale(At, Now) of
true ->
mnesia:write(#schema_migration{version = ?LOCK_VERSION, applied_at = Now}),
ok;
false ->
mnesia:abort(locked)
end
end.
lock_stale(At, Now) ->
SecAt = calendar:datetime_to_gregorian_seconds(At),
SecNow = calendar:datetime_to_gregorian_seconds(Now),
SecNow - SecAt > ?LOCK_STALE_SECONDS.
release_lock() ->
mnesia:sync_transaction(fun() ->
mnesia:delete({?TABLE, ?LOCK_VERSION})
end),
ok.
%% ------------------------------
%% Применение / откат
%% ------------------------------
do_apply_pending() ->
Pending = pending_versions() -- applied_versions(),
lists:foreach(fun(Module) -> code:ensure_loaded(Module) end, Pending),
lists:foldl(fun(Version, ok) ->
try Version:up() of
_ ->
mark_applied(Version),
ok
catch
_:Reason ->
{error, {migration_failed, atom_to_list(Version), Reason}}
end;
(_, Acc) -> Acc
end, ok, Pending).
do_rollback(TargetStr) ->
Target = list_to_atom(TargetStr),
Applied = applied_versions(),
ToRollback = lists:sort(fun(A, B) -> A > B end,
[V || V <- Applied, V > Target]),
lists:foreach(fun(Version) ->
code:ensure_loaded(Version),
try Version:down() of
_ -> unmark_applied(Version)
catch _:Reason ->
throw({rollback_failed, atom_to_list(Version), Reason})
end
end, ToRollback).
applied_versions() ->
[list_to_atom(V) || #schema_migration{version = V} <-
mnesia:dirty_match_object(#schema_migration{_ = '_'}),
not is_lock_version(V)].
pending_versions() ->
?ALL_MIGRATIONS.
is_lock_version(?LOCK_VERSION) -> true;
is_lock_version(_) -> false.
mark_applied(Version) ->
mnesia:dirty_write(#schema_migration{
version = atom_to_list(Version),
applied_at = calendar:universal_time()
}).
unmark_applied(Version) ->
mnesia:dirty_delete({?TABLE, atom_to_list(Version)}).