gitlab-org--gitlab-foss/lib/gitlab/cache/metrics.rb

88 lines
2.3 KiB
Ruby

# frozen_string_literal: true
# Instrumentation for cache efficiency metrics
module Gitlab
module Cache
class Metrics
DEFAULT_BUCKETS = [0, 1, 5].freeze
VALID_BACKING_RESOURCES = [:cpu, :database, :gitaly, :memory, :unknown].freeze
DEFAULT_BACKING_RESOURCE = :unknown
def initialize(
caller_id:,
cache_identifier:,
feature_category: ::Gitlab::FeatureCategories::FEATURE_CATEGORY_DEFAULT,
backing_resource: DEFAULT_BACKING_RESOURCE
)
@caller_id = caller_id
@cache_identifier = cache_identifier
@feature_category = Gitlab::FeatureCategories.default.get!(feature_category)
@backing_resource = fetch_backing_resource!(backing_resource)
end
# Increase cache hit counter
#
def increment_cache_hit
counter.increment(labels.merge(cache_hit: true))
end
# Increase cache miss counter
#
def increment_cache_miss
counter.increment(labels.merge(cache_hit: false))
end
# Measure the duration of cacheable action
#
# @example
# observe_cache_generation do
# cacheable_action
# end
#
def observe_cache_generation(&block)
real_start = Gitlab::Metrics::System.monotonic_time
value = yield
histogram.observe({}, Gitlab::Metrics::System.monotonic_time - real_start)
value
end
private
attr_reader :caller_id, :cache_identifier, :feature_category, :backing_resource
def counter
@counter ||= Gitlab::Metrics.counter(:redis_hit_miss_operations_total, "Hit/miss Redis cache counter")
end
def histogram
@histogram ||= Gitlab::Metrics.histogram(
:redis_cache_generation_duration_seconds,
'Duration of Redis cache generation',
labels,
DEFAULT_BUCKETS
)
end
def labels
@labels ||= {
caller_id: caller_id,
cache_identifier: cache_identifier,
feature_category: feature_category,
backing_resource: backing_resource
}
end
def fetch_backing_resource!(resource)
return resource if VALID_BACKING_RESOURCES.include?(resource)
raise "Unknown backing resource: #{resource}" if Gitlab.dev_or_test_env?
DEFAULT_BACKING_RESOURCE
end
end
end
end