gitlab-org--gitlab-foss/spec/lib/gitlab/metrics/sampler_spec.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

97 lines
2.5 KiB
Ruby

require 'spec_helper'
describe Gitlab::Metrics::Sampler do
let(:sampler) { described_class.new(5) }
after do
Allocations.stop if Gitlab::Metrics.mri?
end
describe '#start' do
it 'gathers a sample at a given interval' do
expect(sampler).to receive(:sleep).with(5)
expect(sampler).to receive(:sample)
expect(sampler).to receive(:loop).and_yield
sampler.start.join
end
end
describe '#sample' do
it 'samples various statistics' do
expect(sampler).to receive(:sample_memory_usage)
expect(sampler).to receive(:sample_file_descriptors)
expect(sampler).to receive(:sample_objects)
expect(sampler).to receive(:sample_gc)
expect(sampler).to receive(:flush)
sampler.sample
end
it 'clears any GC profiles' do
expect(sampler).to receive(:flush)
expect(GC::Profiler).to receive(:clear)
sampler.sample
end
end
describe '#flush' do
it 'schedules the metrics using Sidekiq' do
expect(MetricsWorker).to receive(:perform_async).
with([an_instance_of(Hash)])
sampler.sample_memory_usage
sampler.flush
end
end
describe '#sample_memory_usage' do
it 'adds a metric containing the memory usage' do
expect(Gitlab::Metrics::System).to receive(:memory_usage).
and_return(9000)
expect(Gitlab::Metrics::Metric).to receive(:new).
with('memory_usage', value: 9000).
and_call_original
sampler.sample_memory_usage
end
end
describe '#sample_file_descriptors' do
it 'adds a metric containing the amount of open file descriptors' do
expect(Gitlab::Metrics::System).to receive(:file_descriptor_count).
and_return(4)
expect(Gitlab::Metrics::Metric).to receive(:new).
with('file_descriptors', value: 4).
and_call_original
sampler.sample_file_descriptors
end
end
describe '#sample_objects' do
it 'adds a metric containing the amount of allocated objects' do
expect(Gitlab::Metrics::Metric).to receive(:new).
with('object_counts', an_instance_of(Hash), an_instance_of(Hash)).
at_least(:once).
and_call_original
sampler.sample_objects
end
end
describe '#sample_gc' do
it 'adds a metric containing garbage collection statistics' do
expect(GC::Profiler).to receive(:total_time).and_return(0.24)
expect(Gitlab::Metrics::Metric).to receive(:new).
with('gc_statistics', an_instance_of(Hash)).
and_call_original
sampler.sample_gc
end
end
end