Merge pull request #4 from rabbitmq/handle-stopped-store-in-is_migrat…

…ion_finished mnesia_to_khepri: Support stopped Khepri store in `is_migration_finished/2`
rabbitmq · Oct 26, 2023 · 046439f · 046439f
2 parents a8e8b8d + 7a59c6b
commit 046439f
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Showing 2 changed files with 20 additions and 1 deletion.
diff --git a/src/m2k_table_copy.erl b/src/m2k_table_copy.erl
@@ -70,6 +70,14 @@ proceed(SupPid) ->
       IsFinished :: boolean() | {in_flight, pid()} | undefined.
 
 is_migration_finished(StoreId, MigrationId) when is_binary(MigrationId) ->
+    %% If the Khepri store is not running, we can assume that the migration
+    %% didn't take place yet.
+    case is_khepri_store_running(StoreId) of
+        true  -> is_migration_finished1(StoreId, MigrationId);
+        false -> false
+    end.
+
+is_migration_finished1(StoreId, MigrationId) ->
     ProjectionName = ?PROJECTION_NAME,
     try
         case ets:lookup(ProjectionName, MigrationId) of
@@ -84,7 +92,7 @@ is_migration_finished(StoreId, MigrationId) when is_binary(MigrationId) ->
         error:badarg ->
             case setup_projection(StoreId, ProjectionName) of
                 ok ->
-                    is_migration_finished(StoreId, MigrationId);
+                    is_migration_finished1(StoreId, MigrationId);
                 Error ->
                     ?LOG_WARNING(
                        "Mnesia->Khepri data copy: failed to setup Khepri "
@@ -97,6 +105,10 @@ is_migration_finished(StoreId, MigrationId) when is_binary(MigrationId) ->
             end
     end.
 
+is_khepri_store_running(StoreId) ->
+    RunningStoreIds = khepri:get_store_ids(),
+    lists:member(StoreId, RunningStoreIds).
+
 setup_projection(StoreId, ProjectionName) ->
     ?LOG_DEBUG(
        "Mnesia->Khepri data copy: setup Khepri projection (name: \"~s\")",

diff --git a/test/mnesia_to_khepri_table_copy_SUITE.erl b/test/mnesia_to_khepri_table_copy_SUITE.erl
@@ -589,6 +589,13 @@ is_migration_finished_works(Config) ->
     StoreId = RaSystem,
     MigrationId = store_id_to_mig_id(StoreId),
 
+    %% `is_migration_finished/2' works even if the given store is unavailable.
+    ?assertEqual(
+       false,
+       erpc:call(
+         Node1,
+         mnesia_to_khepri, is_migration_finished, [StoreId, MigrationId])),
+
     ?assertEqual(
        {ok, StoreId},
        rpc:call(Node1, khepri, start, [RaSystem, StoreId])),