gitlab-org--gitlab-foss/lib/gitlab/metrics/sampler.rb
Yorick Peterse f181f05e8a Track object counts using the "allocations" Gem
This allows us to track the counts of actual classes instead of "T_XXX"
nodes. This is only enabled on CRuby as it uses CRuby specific APIs.
2015-12-17 17:25:48 +01:00

98 lines
2.5 KiB
Ruby

module Gitlab
module Metrics
# Class that sends certain metrics to InfluxDB at a specific interval.
#
# This class is used to gather statistics that can't be directly associated
# with a transaction such as system memory usage, garbage collection
# statistics, etc.
class Sampler
# interval - The sampling interval in seconds.
def initialize(interval = 15)
@interval = interval
@metrics = []
@last_minor_gc = Delta.new(GC.stat[:minor_gc_count])
@last_major_gc = Delta.new(GC.stat[:major_gc_count])
if Gitlab::Metrics.mri?
require 'allocations'
Allocations.start
end
end
def start
Thread.new do
Thread.current.abort_on_exception = true
loop do
sleep(@interval)
sample
end
end
end
def sample
sample_memory_usage
sample_file_descriptors
sample_objects
sample_gc
flush
ensure
GC::Profiler.clear
@metrics.clear
end
def flush
MetricsWorker.perform_async(@metrics.map(&:to_hash))
end
def sample_memory_usage
@metrics << Metric.new('memory_usage', value: System.memory_usage)
end
def sample_file_descriptors
@metrics << Metric.
new('file_descriptors', value: System.file_descriptor_count)
end
if Metrics.mri?
def sample_objects
sample = Allocations.to_hash
counts = sample.each_with_object({}) do |(klass, count), hash|
hash[klass.name] = count
end
# Symbols aren't allocated so we'll need to add those manually.
counts['Symbol'] = Symbol.all_symbols.length
counts.each do |name, count|
@metrics << Metric.new('object_counts', { count: count }, type: name)
end
end
else
def sample_objects
end
end
def sample_gc
time = GC::Profiler.total_time * 1000.0
stats = GC.stat.merge(total_time: time)
# We want the difference of GC runs compared to the last sample, not the
# total amount since the process started.
stats[:minor_gc_count] =
@last_minor_gc.compared_with(stats[:minor_gc_count])
stats[:major_gc_count] =
@last_major_gc.compared_with(stats[:major_gc_count])
stats[:count] = stats[:minor_gc_count] + stats[:major_gc_count]
@metrics << Metric.new('gc_statistics', stats)
end
end
end
end