mnesia_rocksdb/test/mnesia_rocksdb_SUITE.erl

766 lines
25 KiB
Erlang

%% -*- mode: erlang; erlang-indent-level: 4; indent-tabs-mode: nil -*-
-module(mnesia_rocksdb_SUITE).
-export([
all/0
, groups/0
, suite/0
, init_per_suite/1
, end_per_suite/1
, init_per_group/2
, end_per_group/2
, init_per_testcase/2
, end_per_testcase/2
]).
-export([ encoding_sext_attrs/1
, encoding_binary_binary/1
, encoding_defaults/1
]).
-export([ mrdb_batch/1
, mrdb_transactions/1
, mrdb_abort_reasons/1
, mrdb_repeated_transactions/1
, mrdb_abort/1
, mrdb_two_procs/1
, mrdb_two_procs_tx_restart/1
, mrdb_two_procs_tx_inner_restart/1
, mrdb_two_procs_snap/1
, mrdb_three_procs/1
]).
-include_lib("common_test/include/ct.hrl").
-define(TABS_CREATED, tables_created).
suite() ->
[].
all() ->
[{group, all_tests}].
groups() ->
[
{all_tests, [sequence], [ {group, checks}
, {group, mrdb} ]}
%% , error_handling ]}
, {checks, [sequence], [ encoding_sext_attrs
, encoding_binary_binary
, encoding_defaults ]}
, {mrdb, [sequence], [ mrdb_batch
, mrdb_transactions
, mrdb_abort_reasons
, mrdb_repeated_transactions
, mrdb_abort
, mrdb_two_procs
, mrdb_two_procs_tx_restart
, mrdb_two_procs_tx_inner_restart
, mrdb_two_procs_snap
, mrdb_three_procs ]}
].
%% error_handling(Config) ->
%% mnesia_rocksdb_error_handling:run(Config).
init_per_suite(Config) ->
tr_ct:set_activation_checkpoint(?TABS_CREATED, Config).
end_per_suite(_Config) ->
ok.
init_per_group(G, Config) when G==mrdb
; G==checks ->
mnesia:stop(),
ok = mnesia_rocksdb_tlib:start_mnesia(reset),
Config;
init_per_group(_, Config) ->
Config.
end_per_group(_, _Config) ->
ok.
init_per_testcase(_, Config) ->
Config.
end_per_testcase(_, _Config) ->
ok.
encoding_sext_attrs(Config) ->
tr_ct:with_trace(fun encoding_sext_attrs_/1, Config,
tr_patterns(mnesia_rocksdb,
[{mnesia_rocksdb,'_',x}], tr_opts())).
encoding_sext_attrs_(Config) ->
Created = create_tabs([{t, [{attributes, [k, v]}]}], Config),
ok = mrdb:insert(t, {t, 1, a}),
ok = mnesia:dirty_write({t, 2, b}),
expect_error(fun() -> mrdb:insert(t, {t, a}) end, ?LINE,
error, {mrdb_abort, badarg}),
expect_error(fun() -> mnesia:dirty_write({t, a}) end, ?LINE,
exit, '_'),
delete_tabs(Created),
ok.
encoding_defaults(Config) ->
UP = fun(T) -> mnesia:table_info(T, user_properties) end,
Created = create_tabs([ {a, [ {attributes, [k, v]}
, {type, set}]}
, {b, [ {attributes, [k, v, w]}
, {type, ordered_set}]}
, {c, [ {attributes, [k, v]}
, {type, bag} ]}], Config),
[{mrdb_encoding,{term,{value,term}}}] = UP(a),
[{mrdb_encoding,{sext,{object,term}}}] = UP(b),
[{mrdb_encoding,{sext,{value,term}}}] = UP(c),
delete_tabs(Created),
ok.
encoding_binary_binary(Config) ->
Created = create_tabs([ {a, [ {attributes, [k,v]}
, {user_properties,
[{mrdb_encoding, {raw, raw}}]}]}
, {b, [ {attributes, [k, v, w]}
, {user_properties,
[{mrdb_encoding, {raw, {object, term}}}]}]}
], Config),
expect_error(fun() ->
create_tab(
c, [ {attributes, [k, v, w]}
, {user_properties,
[{mrdb_encoding, {raw, {value, raw}}}]}])
end, ?LINE, error, '_'),
delete_tabs(Created),
ok.
expect_error(F, Line, Type, Expected) ->
try F() of
Unexpected -> error({unexpected, Line, Unexpected})
catch
Type:Expected ->
ct:log("Caught expected ~p:~p (Line: ~p)", [Type, Expected, Line]),
ok;
Type:Error when Expected == '_' ->
ct:log("Caught expected ~p:_ (Line:~p): ~p", [Type, Line, Error]),
ok
end.
mrdb_batch(Config) ->
Created = create_tabs([{b, []}], Config),
D0 = get_dict(),
mrdb:activity(
batch, rdb,
fun() ->
[mrdb:insert(b, {b, K, K})
|| K <- lists:seq(1, 10)]
end),
dictionary_unchanged(D0),
[[{b,K,K}] = mrdb:read(b, K) || K <- lists:seq(1, 10)],
expect_error(
fun() -> mrdb:activity(
batch, rdb,
fun() ->
mrdb:insert(b, {b, 11, 11}),
error(willful_abort)
end)
end, ?LINE, error, '_'),
dictionary_unchanged(D0),
[] = mrdb:read(b, 11),
TRef = mrdb:get_ref(b),
mrdb:activity(
batch, rdb,
fun() ->
mrdb:insert(TRef, {b, 12, 12})
end),
dictionary_unchanged(D0),
[{b, 12, 12}] = mrdb:read(b, 12),
mrdb:as_batch(b, fun(R) ->
mrdb:insert(R, {b, 13, 13})
end),
dictionary_unchanged(D0),
[{b, 13, 13}] = mrdb:read(b, 13),
delete_tabs(Created),
ok.
mrdb_transactions(Config) ->
tr_ct:with_trace(fun mrdb_transactions_/1, Config,
tr_patterns(
mnesia_rocksdb_admin,
[{mnesia_rocksdb_admin,'_',x}], tr_opts())).
mrdb_transactions_(Config) ->
Created = create_tabs([{tx, []}], Config),
mrdb:insert(tx, {tx, a, 1}),
[_] = mrdb:read(tx, a),
D0 = get_dict(),
mrdb:activity(
tx, rdb,
fun() ->
[{tx,a,N}] = mrdb:read(tx, a),
N1 = N+1,
ok = mrdb:insert(tx, {tx,a,N1}),
[{tx,a,N1}] = mrdb:read(tx, a),
ok
end),
dictionary_unchanged(D0),
[{tx,a,2}] = mrdb:read(tx,a),
delete_tabs(Created),
ok.
mrdb_abort_reasons(_Config) ->
Prev = mnesia_rocksdb_admin:set_and_cache_env(mnesia_compatible_aborts, true),
X = some_value,
compare_txs('throw', fun() -> throw(X) end),
compare_txs('exit' , fun() -> exit(X) end),
compare_txs('error', fun() -> error(X) end),
compare_txs('abort', fun() -> mnesia:abort(X) end),
compare_txs('abort' , fun() -> mrdb:abort(X) end),
mnesia_rocksdb_admin:set_and_cache_env(mnesia_compatible_aborts, Prev),
ok.
compare_txs(Type, F) ->
{caught, exit, {aborted, EMn}} = mnesia_tx(F),
{caught, exit, {aborted, EMr}} = mrdb_tx(F),
ct:log("Mnesia = ~p/~p", [Type, EMn]),
ct:log("Mrdb = ~p/~p", [Type, EMr]),
case {Type, EMn, EMr} of
{error, {some_value, [_|_]}, {some_value, []}} -> ok;
{throw, {throw, some_value}, {throw, some_value}} -> ok;
{exit, some_value, some_value} -> ok;
{abort, some_value, some_value} -> ok
end.
mnesia_tx(F) ->
try
mnesia:activity(transaction, F)
catch
C:E ->
{caught, C, E}
end.
mrdb_tx(F) ->
try
mrdb:activity(transaction, rdb, F)
catch
C:E ->
{caught, C, E}
end.
mrdb_repeated_transactions(Config) ->
Created = create_tabs([{rtx, []}], Config),
mrdb:insert(rtx, {rtx, a, 0}),
[_] = mrdb:read(rtx, a),
Fun = fun() ->
[{rtx, a, N}] = mrdb:read(rtx, a),
N1 = N+1,
ok = mrdb:insert(rtx, {rtx, a, N1})
end,
D0 = get_dict(),
[ok = mrdb:activity(tx, rdb, Fun) || _ <- lists:seq(1,100)],
dictionary_unchanged(D0),
[{rtx,a,100}] = mrdb:read(rtx, a),
delete_tabs(Created),
ok.
mrdb_abort(Config) ->
Created = create_tabs([{tx_abort, []}], Config),
mrdb:insert(tx_abort, {tx_abort, a, 1}),
Pre = mrdb:read(tx_abort, a),
D0 = get_dict(),
TRes = try mrdb:activity(
tx, rdb,
fun() ->
[{tx_abort, a, N}] = mrdb:read(tx_abort, a),
error(abort_here),
ok = mrdb:insert(tx_abort, [{tx_abort, a, N+1}]),
noooo
end)
catch
error:abort_here ->
ok
end,
dictionary_unchanged(D0),
ok = TRes,
Pre = mrdb:read(tx_abort, a),
delete_tabs(Created),
ok.
mrdb_two_procs(Config) ->
tr_ct:with_trace(fun mrdb_two_procs_/1, Config,
tr_flags(
{self(), [call, sos, p, 'receive']},
tr_patterns(
mrdb, [ {mrdb, insert, 2, x}
, {mrdb, read, 2, x}
, {mrdb, retry_activity, 3, x}
, {mrdb, try_f, 2, x}
, {mrdb, incr_attempt, 2, x}
, {mrdb_mutex, do, 2, x}
, {mrdb_mutex_serializer, do, 2, x}
, {?MODULE, wait_for_other, 2, x}
, {?MODULE, go_ahead_other, 1, x}
, {mrdb, activity, x}], tr_opts()))).
mrdb_two_procs_(Config) ->
R = ?FUNCTION_NAME,
Parent = self(),
Created = create_tabs([{R, []}], Config),
mrdb:insert(R, {R, a, 1}),
Pre = mrdb:read(R, a),
F0 = fun() ->
wait_for_other(Parent, ?LINE),
ok = mrdb:insert(R, {R, a, 17}),
wait_for_other(Parent, ?LINE)
end,
{POther, MRef} = spawn_opt(
fun() ->
D0 = get_dict(),
ok = mrdb:activity(tx, rdb, F0),
dictionary_unchanged(D0)
end, [monitor]),
F1 = fun() ->
Pre = mrdb:read(R, a),
go_ahead_other(POther),
await_other_down(POther, MRef, ?LINE),
%% The test proc is still inside the transaction, and POther
%% has terminated/committed. If we now read 'a', we should see
%% the value that POther wrote (no isolation).
[{R, a, 17}] = mrdb:read(R, a),
ok = mrdb:insert(R, {R, a, 18})
end,
go_ahead_other(0, POther),
Do0 = get_dict(),
%% Our transaction should fail due to the resource conflict, and because
%% we're not using retries.
try mrdb:activity({tx, #{no_snapshot => true,
retries => 0}}, rdb, F1) of
ok -> error(unexpected)
catch
error:{error, "Resource busy" ++ _} ->
ok
end,
dictionary_unchanged(Do0),
[{R, a, 17}] = mrdb:read(R, a),
delete_tabs(Created),
ok.
mrdb_two_procs_tx_restart(Config) ->
tr_ct:with_trace(fun mrdb_two_procs_tx_restart_/1, Config,
light_tr_opts()).
mrdb_two_procs_tx_restart_(Config) ->
R = ?FUNCTION_NAME,
Parent = self(),
Created = create_tabs([{R, []}], Config),
check_stats(rdb),
mrdb:insert(R, {R, a, 1}),
Pre = mrdb:read(R, a),
F0 = fun() ->
wait_for_other(Parent, ?LINE),
ok = mrdb:insert(R, {R, a, 17}),
wait_for_other(Parent, ?LINE)
end,
{POther, MRef} = spawn_opt(
fun() ->
ok = mrdb:activity(tx, rdb, F0)
end, [monitor]),
F1 = fun() ->
OtherWrite = [{R, a, 17}],
Att = get_attempt(),
Expected = case Att of
0 -> Pre;
_ -> OtherWrite
end,
Expected = mrdb:read(R, a),
go_ahead_other(POther),
await_other_down(POther, MRef, ?LINE),
OtherWrite = mrdb:read(R, a),
ok = mrdb:insert(R, {R, a, 18})
end,
go_ahead_other(0, POther),
Do0 = get_dict(),
mrdb:activity({tx, #{no_snapshot => true}}, rdb, F1),
dictionary_unchanged(Do0),
check_stats(rdb),
[{R, a, 18}] = mrdb:read(R, a),
delete_tabs(Created),
ok.
mrdb_two_procs_tx_inner_restart(Config) ->
tr_ct:with_trace(fun mrdb_two_procs_tx_inner_restart_/1, Config,
dbg_tr_opts()).
mrdb_two_procs_tx_inner_restart_(Config) ->
R = ?FUNCTION_NAME,
Parent = self(),
Created = create_tabs([{R, []}], Config),
mrdb:insert(R, {R, a, 1}),
mrdb:insert(R, {R, b, 1}),
PreA = mrdb:read(R, a),
PreB = mrdb:read(R, b),
#{inner_retries := Ri0, outer_retries := Ro0} = check_stats(rdb),
F0 = fun() ->
wait_for_other(Parent, ?LINE),
ok = mrdb:insert(R, {R, a, 17}),
wait_for_other(Parent, ?LINE)
end,
F1 = fun() ->
wait_for_other(Parent, ?LINE),
ok = mrdb:insert(R, {R, b, 147}),
wait_for_other(Parent, ?LINE)
end,
Spawn = fun(F) ->
Res = spawn_opt(
fun() ->
ok = mrdb:activity(tx, rdb, F)
end, [monitor]),
Res
end,
{P1, MRef1} = Spawn(F0),
{P2, MRef2} = Spawn(F1),
F2 = fun() ->
PostA = [{R, a, 17}], % once F0 (P1) has committed
PostB = [{R, b, 147}], % once F1 (P2) has committed
ARes = mrdb:read(R, a), % We need to read first to establish a pre-image
BRes = mrdb:read(R, b),
Att = get_attempt(),
ct:log("Att = ~p", [Att]),
case Att of
0 -> % This is the first run (no retry yet)
ARes = PreA,
BRes = PreB,
go_ahead_other(0, P1), % Having our pre-image, now let P1 write
go_ahead_other(0, P1), % Let P1 commit, then await DOWN (normal)
await_other_down(P1, MRef1, ?LINE),
PostA = mrdb:read(R, a); % now, P1's write should leak through here
{0, 1} -> % This is the first (outer) retry
go_ahead_other(0, P2), % Let P2 write
go_ahead_other(0, P2), % Let P2 commit, then await DOWN (normal)
await_other_down(P2, MRef2, ?LINE),
PostA = mrdb:read(R, a), % now we should see writes from both P1
PostB = mrdb:read(R, b); % ... and P2
{1, 1} ->
PostA = mrdb:read(R, a),
PostB = mrdb:read(R, b),
ok
end,
mrdb:insert(R, {R, a, 18}),
mrdb:insert(R, {R, b, 18})
end,
Do0 = get_dict(),
mrdb:activity({tx, #{no_snapshot => true, retries => {1,1}}}, rdb, F2),
check_stats(rdb),
dictionary_unchanged(Do0),
[{R, a, 18}] = mrdb:read(R, a),
[{R, b, 18}] = mrdb:read(R, b),
#{inner_retries := Ri1, outer_retries := Ro1} = check_stats(rdb),
{restarts, {1, 1}} = {restarts, {Ri1 - Ri0, Ro1 - Ro0}},
delete_tabs(Created),
ok.
%
%% For testing purposes, we use side-effects inside the transactions
%% to synchronize the concurrent transactions. If a transaction fails due
%% to "Resource busy", it can re-run, but then mustn't attempt to sync with
%% the other transaction, which is already committed.
%%
%% To achieve this, we rely on the `mrdb:current_context()` function, which gives
%% us information about which is the current attempt; we only sync on the first
%% attempt, and ignore the sync ops on retries.
%%
-define(IF_FIRST(N, Expr),
if N == 0 ->
Expr;
true ->
ok
end).
mrdb_two_procs_snap(Config) ->
%% _snap is now the default tx mode
R = ?FUNCTION_NAME,
Parent = self(),
Created = create_tabs([{R, []}], Config),
mrdb:insert(R, {R, a, 1}),
Pre = mrdb:read(R, a),
mrdb:insert(R, {R, b, 11}),
PreB = mrdb:read(R, b),
F0 = fun() ->
ok = mrdb:insert(R, {R, a, 17}),
wait_for_other(Parent, ?LINE)
end,
{POther, MRef} =
spawn_opt(fun() ->
D0 = get_dict(),
ok = mrdb:activity(tx, rdb, F0),
dictionary_unchanged(D0)
end, [monitor]),
F1 = fun() ->
Att = get_attempt(),
go_ahead_other(Att, POther),
ARes = mrdb:read(R, a),
ARes = case Att of
0 -> Pre;
_ -> [{R, a, 17}]
end,
await_other_down(POther, MRef, ?LINE),
PreB = mrdb:read(R, b),
mrdb:insert(R, {R, b, 18}),
1477
end,
Do0 = get_dict(),
1477 = mrdb:activity(tx, rdb, F1),
dictionary_unchanged(Do0),
[{R, a, 17}] = mrdb:read(R, a),
[{R, b, 18}] = mrdb:read(R, b),
delete_tabs(Created),
ok.
%% We spawn two helper processes, making it 3 transactions, with the one
%% in the parent process. P2 writes to key `a`, which the other two try to read.
%% We make sure that P2 commits before finishing the other two, and P3 and the
%% main thread sync, so as to maximize the contention for the retry lock.
mrdb_three_procs(Config) ->
tr_ct:with_trace(fun mrdb_three_procs_/1, Config, dbg_tr_opts()).
mrdb_three_procs_(Config) ->
R = ?FUNCTION_NAME,
Parent = self(),
Created = create_tabs([{R, []}], Config),
A0 = {R, a, 1},
A1 = {R, a, 11},
A2 = {R, a, 12},
ok = mrdb:insert(R, A0),
F1 = fun() ->
ok = mrdb:insert(R, A1),
ok = mrdb:insert(R, {R, p1, 1})
end,
{P1, MRef1} =
spawn_opt(fun() ->
D0 = get_dict(),
do_when_p_allows(
0, Parent, ?LINE,
fun() ->
ok = mrdb:activity({tx,#{retries => 0}}, rdb, F1)
end),
dictionary_unchanged(D0)
end, [monitor]),
F2 = fun() ->
[A0] = mrdb:read(R, a),
Att = get_attempt(),
wait_for_other(Att, Parent, ?LINE),
do_when_p_allows(
Att, Parent, ?LINE,
fun() ->
[A1] = mrdb:read(R, a),
ok = mrdb:insert(R, A2),
ok = mrdb:insert(R, {R, p2, 1})
end)
end,
{P2, MRef2} =
spawn_opt(fun() ->
D0 = get_dict(),
try mrdb:activity(
{tx, #{retries => 0,
no_snapshot => true}}, rdb, F2) of
ok -> error(unexpected)
catch
error:{error, "Resource busy" ++ _} ->
ok
end,
dictionary_unchanged(D0)
end, [monitor]),
Do0 = get_dict(),
ok = mrdb:activity(tx, rdb,
fun() ->
Att = get_attempt(),
ARes = case Att of
0 -> [A0];
_ -> [A1]
end,
%% First, ensure that P2 tx is running
go_ahead_other(Att, P2),
ARes = mrdb:read(R, a),
allow_p(Att, P1, ?LINE),
ARes = mrdb:read(R, a),
allow_p(Att, P2, ?LINE),
ARes = mrdb:read(R, a),
await_other_down(P1, MRef1, ?LINE),
await_other_down(P2, MRef2, ?LINE),
ok = mrdb:insert(R, {R, p0, 1})
end),
dictionary_unchanged(Do0),
[{R, p1, 1}] = mrdb:read(R, p1),
[] = mrdb:read(R, p2),
[A1] = mrdb:read(R, a),
[{R, p0, 1}] = mrdb:read(R, p0),
delete_tabs(Created),
ok.
tr_opts() ->
#{patterns => [ {mrdb, '_', '_', x}
, {mrdb_lib, '_', '_', x}
, {tr_ttb, event, 3, []}
, {?MODULE, go_ahead_other, 3, x}
, {?MODULE, wait_for_other, 3, x}
, {?MODULE, await_other_down, 3, x}
, {?MODULE, do_when_p_allows, 4, x}
, {?MODULE, allow_p, 3, x}
, {?MODULE, check_stats, 1, x}
]}.
light_tr_opts() ->
tr_flags(
{self(), [call, sos, p]},
tr_patterns(
mrdb, [ {mrdb, insert, 2, x}
, {mrdb, read, 2, x}
, {mrdb, activity, x} ], tr_opts())).
dbg_tr_opts() ->
tr_flags(
{self(), [call, sos, p, 'receive']},
tr_patterns(
mrdb, [ {mrdb, insert, 2, x}
, {mrdb, read, 2, x}
, {mrdb, retry_activity, 3, x}
, {mrdb, try_f, 2, x}
, {mrdb, incr_attempt, 2, x}
, {mrdb, current_context, 0, x}
, {mrdb_mutex, do, 2, x}
, {mrdb_mutex_serializer, do, 2, x}
, {?MODULE, wait_for_other, 2, x}
, {?MODULE, go_ahead_other, 1, x}
, {mrdb, activity, x} ], tr_opts())).
tr_patterns(Mod, Ps, #{patterns := Pats} = Opts) ->
Pats1 = [P || P <- Pats, element(1,P) =/= Mod],
Opts#{patterns => Ps ++ Pats1}.
tr_flags(Flags, Opts) when is_map(Opts) ->
Opts#{flags => Flags}.
wait_for_other(Parent, L) ->
wait_for_other(get_attempt(), Parent, 1000, L).
wait_for_other(Att, Parent, L) ->
wait_for_other(Att, Parent, 1000, L).
wait_for_other(0, Parent, Timeout, L) ->
MRef = monitor(process, Parent),
Parent ! {self(), ready},
receive
{Parent, cont} ->
demonitor(MRef),
Parent ! {self(), cont_ack},
ok;
{'DOWN', MRef, _, _, Reason} ->
ct:log("Parent died, Reason = ~p", [Reason]),
exit(Reason)
after Timeout ->
demonitor(MRef),
error({inner_timeout, L})
end;
wait_for_other(_, _, _, _) ->
ok.
do_when_p_allows(Att, P, Line, F) ->
wait_for_other(Att, P, Line),
F(),
%% Tell P that we're done
go_ahead_other(Att, P, Line),
%% Wait for P to acknowlege
wait_for_other(Att, P, Line).
allow_p(Att, P, Line) ->
go_ahead_other(Att, P),
%% This is where P does its thing.
wait_for_other(Att, P, Line),
%% Acknowledge
go_ahead_other(Att, P, Line).
go_ahead_other(POther) ->
go_ahead_other(get_attempt(), POther).
go_ahead_other(Att, POther) ->
go_ahead_other(Att, POther, 1000).
go_ahead_other(Att, POther, Timeout) ->
?IF_FIRST(Att, go_ahead_other_(POther, Timeout)).
go_ahead_other_(POther, Timeout) ->
receive
{POther, ready} ->
POther ! {self(), cont},
receive
{POther, cont_ack} ->
ok
after Timeout ->
error(cont_ack_timeout)
end
after Timeout ->
error(go_ahead_timeout)
end.
%% Due to transaction restarts, we may already have collected
%% a DOWN message. In this case, P will already be dead, and there
%% will not be a 'DOWN' messsage still in the msg queue.
%% This is fine (we assume it is), and we just make sure that the
%% process didn't die abnormally.
await_other_down(P, MRef, Line) ->
Attempt = get_attempt(),
?IF_FIRST(Attempt, await_other_down_(P, MRef, Line)).
await_other_down_(P, MRef, Line) ->
receive {'DOWN', MRef, _, _, Reason} ->
case Reason of
normal -> ok;
_ ->
error({abnormal_termination,
[ {pid, P}
, {mref, MRef}
, {line, Line}
, {reason, Reason}]})
end
after 1000 ->
error({monitor_timeout, Line})
end.
get_attempt() ->
#{activity := #{attempt := Attempt}} = mrdb:current_context(),
Attempt.
create_tabs(Tabs, Config) ->
Res = lists:map(fun create_tab/1, Tabs),
tr_ct:trace_checkpoint(?TABS_CREATED, Config),
Res.
create_tab({T, Opts}) -> create_tab(T, Opts).
create_tab(T, Opts) ->
{atomic, ok} = mnesia:create_table(T, [{rdb,[node()]} | Opts]),
T.
delete_tabs(Tabs) ->
[{atomic,ok} = mnesia:delete_table(T) || T <- Tabs],
ok.
get_dict() ->
{dictionary, D} = process_info(self(), dictionary),
[X || {K,_} = X <- D,
K =/= log_timestamp].
dictionary_unchanged(Old) ->
New = get_dict(),
#{ deleted := []
, added := [] } = #{ deleted => Old -- New
, added => New -- Old },
ok.
check_stats(Alias) ->
Stats = mrdb_stats:get(Alias),
ct:log("Stats: ~p", [Stats]),
Stats.