1 files changed, 12 insertions, 2 deletions
diff --git a/lib/gitlab/database/background_migration/batched_migration.rb b/lib/gitlab/database/background_migration/batched_migration.rb
index 6aed1eed994..45f52765d0f 100644
--- a/lib/gitlab/database/background_migration/batched_migration.rb
+++ b/lib/gitlab/database/background_migration/batched_migration.rb
@@ -8,6 +8,7 @@ module Gitlab
         BATCH_CLASS_MODULE = "#{JOB_CLASS_MODULE}::BatchingStrategies"
         MAXIMUM_FAILED_RATIO = 0.5
         MINIMUM_JOBS = 50
+        FINISHED_PROGRESS_VALUE = 100
 
         self.table_name = :batched_background_migrations
 
@@ -24,6 +25,7 @@ module Gitlab
 
         scope :queue_order, -> { order(id: :asc) }
         scope :queued, -> { with_statuses(:active, :paused) }
+        scope :ordered_by_created_at_desc, -> { order(created_at: :desc) }
 
         # on_hold_until is a temporary runtime status which puts execution "on hold"
         scope :executable, -> { with_status(:active).where('on_hold_until IS NULL OR on_hold_until < NOW()') }
@@ -57,11 +59,11 @@ module Gitlab
           state :finalizing, value: 5
 
           event :pause do
-            transition any => :paused
+            transition [:active, :paused] => :paused
           end
 
           event :execute do
-            transition any => :active
+            transition [:active, :paused, :failed] => :active
           end
 
           event :finish do
@@ -231,7 +233,15 @@ module Gitlab
           "BatchedMigration[id: #{id}]"
         end
 
+        # Computes an estimation of the progress of the migration in percents.
+        #
+        # Because `total_tuple_count` is an estimation of the tuples based on DB statistics
+        # when the migration is complete there can actually be more or less tuples that initially
+        # estimated as `total_tuple_count` so the progress may not show 100%. For that reason when
+        # we know migration completed successfully, we just return the 100 value
         def progress
+          return FINISHED_PROGRESS_VALUE if finished?
+
           return unless total_tuple_count.to_i > 0
 
           100 * migrated_tuple_count / total_tuple_count