1 files changed, 23 insertions, 4 deletions
diff --git a/lib/gitlab/database/reindexing.rb b/lib/gitlab/database/reindexing.rb
index 841e04ccbd1..04b409a9306 100644
--- a/lib/gitlab/database/reindexing.rb
+++ b/lib/gitlab/database/reindexing.rb
@@ -8,6 +8,13 @@ module Gitlab
 
       SUPPORTED_TYPES = %w(btree gist).freeze
 
+      # When dropping an index, we acquire a SHARE UPDATE EXCLUSIVE lock,
+      # which only conflicts with DDL and vacuum. We therefore execute this with a rather
+      # high lock timeout and a long pause in between retries. This is an alternative to
+      # setting a high statement timeout, which would lead to a long running query with effects
+      # on e.g. vacuum.
+      REMOVE_INDEX_RETRY_CONFIG = [[1.minute, 9.minutes]] * 30
+
       # candidate_indexes: Array of Gitlab::Database::PostgresIndex
       def self.perform(candidate_indexes, how_many: DEFAULT_INDEXES_PER_INVOCATION)
         IndexSelection.new(candidate_indexes).take(how_many).each do |index|
@@ -15,10 +22,22 @@ module Gitlab
         end
       end
 
-      def self.candidate_indexes
-        Gitlab::Database::PostgresIndex
-          .not_match("#{ReindexConcurrently::TEMPORARY_INDEX_PATTERN}$")
-          .reindexing_support
+      def self.cleanup_leftovers!
+        PostgresIndex.reindexing_leftovers.each do |index|
+          Gitlab::AppLogger.info("Removing index #{index.identifier} which is a leftover, temporary index from previous reindexing activity")
+
+          retries = Gitlab::Database::WithLockRetriesOutsideTransaction.new(
+            timing_configuration: REMOVE_INDEX_RETRY_CONFIG,
+            klass: self.class,
+            logger: Gitlab::AppLogger
+          )
+
+          retries.run(raise_on_exhaustion: false) do
+            ApplicationRecord.connection.tap do |conn|
+              conn.execute("DROP INDEX CONCURRENTLY IF EXISTS #{conn.quote_table_name(index.schema)}.#{conn.quote_table_name(index.name)}")
+            end
+          end
+        end
       end
     end
   end