Fix metric files being wiped after the app starts

When we hit our app with the initial request, in `warmup`,
some metrics already being created as well as corresponding files.
If we do `multiproc_file_dir` cleanup after that, we delete the files
from the dir while keeping them in memory which leads to the incorrect
behavior: the metric is being updated in in-memory, while is not present
in the db, not sent to Prometheus as the result.

1 files changed, 0 insertions, 19 deletions

diff --git a/config/initializers/7_prometheus_metrics.rb b/config/initializers/7_prometheus_metrics.rb
index 3f2691dde95..70e5dcd042e 100644
--- a/config/initializers/7_prometheus_metrics.rb
+++ b/config/initializers/7_prometheus_metrics.rb
@@ -51,22 +51,3 @@ if !Rails.env.test? && Gitlab::Metrics.prometheus_metrics_enabled?
     end
   end
 end
-
-def cleanup_prometheus_multiproc_dir
-  # The following is necessary to ensure stale Prometheus metrics don't
-  # accumulate over time. It needs to be done in this hook as opposed to
-  # inside an init script to ensure metrics files aren't deleted after new
-  # unicorn workers start after a SIGUSR2 is received.
-  if dir = ::Prometheus::Client.configuration.multiprocess_files_dir
-    old_metrics = Dir[File.join(dir, '*.db')]
-    FileUtils.rm_rf(old_metrics)
-  end
-end
-
-Gitlab::Cluster::LifecycleEvents.on_master_start do
-  cleanup_prometheus_multiproc_dir
-end
-
-Gitlab::Cluster::LifecycleEvents.on_master_restart do
-  cleanup_prometheus_multiproc_dir
-end