debian-mirror-gitlab/lib/gitlab/checks/matching_merge_request.rb
2021-09-04 02:52:04 +05:30

76 lines
2.5 KiB
Ruby

# frozen_string_literal: true
module Gitlab
module Checks
class MatchingMergeRequest
TOTAL_METRIC = :gitlab_merge_request_match_total
STALE_METRIC = :gitlab_merge_request_match_stale_secondary
def initialize(newrev, branch_name, project)
@newrev = newrev
@branch_name = branch_name
@project = project
end
def match?
if ::Gitlab::Database::LoadBalancing.enable?
# When a user merges a merge request, the following sequence happens:
#
# 1. Sidekiq: MergeService runs and updates the merge request in a locked state.
# 2. Gitaly: The UserMergeBranch RPC runs.
# 3. Gitaly (gitaly-ruby): This RPC calls the pre-receive hook.
# 4. Rails: This hook makes an API request to /api/v4/internal/allowed.
# 5. Rails: This API check does a SQL query for locked merge
# requests with a matching SHA.
#
# Since steps 1 and 5 will happen on different database
# sessions, replication lag could erroneously cause step 5 to
# report no matching merge requests. To avoid this, we check
# the write location to ensure the replica can make this query.
track_session_metrics do
::Gitlab::Database::LoadBalancing::Sticking.select_valid_host(:project, @project.id)
end
end
# rubocop: disable CodeReuse/ActiveRecord
@project.merge_requests
.with_state(:locked)
.where(in_progress_merge_commit_sha: @newrev, target_branch: @branch_name)
.exists?
# rubocop: enable CodeReuse/ActiveRecord
end
private
def track_session_metrics
before = ::Gitlab::Database::LoadBalancing::Session.current.use_primary?
yield
after = ::Gitlab::Database::LoadBalancing::Session.current.use_primary?
increment_attempt_count
if !before && after
increment_stale_secondary_count
end
end
def increment_attempt_count
total_counter.increment
end
def increment_stale_secondary_count
stale_counter.increment
end
def total_counter
@total_counter ||= ::Gitlab::Metrics.counter(TOTAL_METRIC, 'Total number of merge request match attempts')
end
def stale_counter
@stale_counter ||= ::Gitlab::Metrics.counter(STALE_METRIC, 'Total number of merge request match attempts with lagging secondary')
end
end
end
end