Commit 20bff3bc authored by Matthias Käppler's avatar Matthias Käppler Committed by Kamil Trzciński

Report USS+PSS from ruby_sampler

Reports the unique & proportional set size into prometheus.

Change is behind a feature toggle.
parent 986b5a40
......@@ -34,14 +34,16 @@ module Gitlab
def init_metrics
metrics = {
file_descriptors: ::Gitlab::Metrics.gauge(with_prefix(:file, :descriptors), 'File descriptors used', labels),
memory_bytes: ::Gitlab::Metrics.gauge(with_prefix(:memory, :bytes), 'Memory used', labels),
process_cpu_seconds_total: ::Gitlab::Metrics.gauge(with_prefix(:process, :cpu_seconds_total), 'Process CPU seconds total'),
process_max_fds: ::Gitlab::Metrics.gauge(with_prefix(:process, :max_fds), 'Process max fds'),
process_resident_memory_bytes: ::Gitlab::Metrics.gauge(with_prefix(:process, :resident_memory_bytes), 'Memory used', labels),
process_start_time_seconds: ::Gitlab::Metrics.gauge(with_prefix(:process, :start_time_seconds), 'Process start time seconds'),
sampler_duration: ::Gitlab::Metrics.counter(with_prefix(:sampler, :duration_seconds_total), 'Sampler time', labels),
gc_duration_seconds: ::Gitlab::Metrics.histogram(with_prefix(:gc, :duration_seconds), 'GC time', labels, GC_REPORT_BUCKETS)
file_descriptors: ::Gitlab::Metrics.gauge(with_prefix(:file, :descriptors), 'File descriptors used', labels),
memory_bytes: ::Gitlab::Metrics.gauge(with_prefix(:memory, :bytes), 'Memory used (RSS)', labels),
process_cpu_seconds_total: ::Gitlab::Metrics.gauge(with_prefix(:process, :cpu_seconds_total), 'Process CPU seconds total'),
process_max_fds: ::Gitlab::Metrics.gauge(with_prefix(:process, :max_fds), 'Process max fds'),
process_resident_memory_bytes: ::Gitlab::Metrics.gauge(with_prefix(:process, :resident_memory_bytes), 'Memory used (RSS)', labels),
process_unique_memory_bytes: ::Gitlab::Metrics.gauge(with_prefix(:process, :unique_memory_bytes), 'Memory used (USS)', labels),
process_proportional_memory_bytes: ::Gitlab::Metrics.gauge(with_prefix(:process, :proportional_memory_bytes), 'Memory used (PSS)', labels),
process_start_time_seconds: ::Gitlab::Metrics.gauge(with_prefix(:process, :start_time_seconds), 'Process start time seconds'),
sampler_duration: ::Gitlab::Metrics.counter(with_prefix(:sampler, :duration_seconds_total), 'Sampler time', labels),
gc_duration_seconds: ::Gitlab::Metrics.histogram(with_prefix(:gc, :duration_seconds), 'GC time', labels, GC_REPORT_BUCKETS)
}
GC.stat.keys.each do |key|
......@@ -85,10 +87,15 @@ module Gitlab
end
def set_memory_usage_metrics
memory_usage = System.memory_usage
metrics[:memory_bytes].set(labels, memory_usage)
metrics[:process_resident_memory_bytes].set(labels, memory_usage)
memory_rss = System.memory_usage
metrics[:memory_bytes].set(labels, memory_rss)
metrics[:process_resident_memory_bytes].set(labels, memory_rss)
if Feature.enabled?(:collect_memory_uss_pss)
memory_uss_pss = System.memory_usage_uss_pss
metrics[:process_unique_memory_bytes].set(labels, memory_uss_pss[:uss])
metrics[:process_proportional_memory_bytes].set(labels, memory_uss_pss[:pss])
end
end
end
end
......
......@@ -7,47 +7,37 @@ module Gitlab
# This module relies on the /proc filesystem being available. If /proc is
# not available the methods of this module will be stubbed.
module System
if File.exist?('/proc')
# Returns the current process' memory usage in bytes.
def self.memory_usage
mem = 0
match = File.read('/proc/self/status').match(/VmRSS:\s+(\d+)/)
if match && match[1]
mem = match[1].to_f * 1024
end
mem
end
def self.file_descriptor_count
Dir.glob('/proc/self/fd/*').length
end
def self.max_open_file_descriptors
match = File.read('/proc/self/limits').match(/Max open files\s*(\d+)/)
return unless match && match[1]
PROC_STATUS_PATH = '/proc/self/status'
PROC_SMAPS_ROLLUP_PATH = '/proc/self/smaps_rollup'
PROC_LIMITS_PATH = '/proc/self/limits'
PROC_FD_GLOB = '/proc/self/fd/*'
PRIVATE_PAGES_PATTERN = /^(Private_Clean|Private_Dirty|Private_Hugetlb):\s+(?<value>\d+)/.freeze
PSS_PATTERN = /^Pss:\s+(?<value>\d+)/.freeze
RSS_PATTERN = /VmRSS:\s+(?<value>\d+)/.freeze
MAX_OPEN_FILES_PATTERN = /Max open files\s*(?<value>\d+)/.freeze
# Returns the current process' RSS (resident set size) in bytes.
def self.memory_usage
sum_matches(PROC_STATUS_PATH, rss: RSS_PATTERN)[:rss].kilobytes
end
match[1].to_i
end
else
def self.memory_usage
0.0
end
# Returns the current process' USS/PSS (unique/proportional set size) in bytes.
def self.memory_usage_uss_pss
sum_matches(PROC_SMAPS_ROLLUP_PATH, uss: PRIVATE_PAGES_PATTERN, pss: PSS_PATTERN)
.transform_values(&:kilobytes)
end
def self.file_descriptor_count
0
end
def self.file_descriptor_count
Dir.glob(PROC_FD_GLOB).length
end
def self.max_open_file_descriptors
0
end
def self.max_open_file_descriptors
sum_matches(PROC_LIMITS_PATH, max_fds: MAX_OPEN_FILES_PATTERN)[:max_fds]
end
def self.cpu_time
Process
.clock_gettime(Process::CLOCK_PROCESS_CPUTIME_ID, :float_second)
Process.clock_gettime(Process::CLOCK_PROCESS_CPUTIME_ID, :float_second)
end
# Returns the current real time in a given precision.
......@@ -78,6 +68,27 @@ module Gitlab
end_time - start_time
end
# Given a path to a file in /proc and a hash of (metric, pattern) pairs,
# sums up all values found for those patterns under the respective metric.
def self.sum_matches(proc_file, **patterns)
results = patterns.transform_values { 0 }
begin
File.foreach(proc_file) do |line|
patterns.each do |metric, pattern|
match = line.match(pattern)
value = match&.named_captures&.fetch('value', 0)
results[metric] += value.to_i
end
end
rescue Errno::ENOENT
# This means the procfile we're reading from did not exist;
# this is safe to ignore, since we initialize each metric to 0
end
results
end
end
end
end
......@@ -19,20 +19,19 @@ describe Gitlab::Metrics::Samplers::RubySampler do
end
describe '#sample' do
it 'samples various statistics' do
expect(Gitlab::Metrics::System).to receive(:cpu_time)
expect(Gitlab::Metrics::System).to receive(:file_descriptor_count)
expect(Gitlab::Metrics::System).to receive(:memory_usage)
expect(Gitlab::Metrics::System).to receive(:max_open_file_descriptors)
expect(sampler).to receive(:sample_gc)
it 'adds a metric containing the process resident memory bytes' do
expect(Gitlab::Metrics::System).to receive(:memory_usage).and_return(9000)
expect(sampler.metrics[:process_resident_memory_bytes]).to receive(:set).with({}, 9000)
sampler.sample
end
it 'adds a metric containing the process resident memory bytes' do
expect(Gitlab::Metrics::System).to receive(:memory_usage).and_return(9000)
it 'adds a metric containing the process unique and proportional memory bytes' do
expect(Gitlab::Metrics::System).to receive(:memory_usage_uss_pss).and_return(uss: 9000, pss: 10_000)
expect(sampler.metrics[:process_resident_memory_bytes]).to receive(:set).with({}, 9000)
expect(sampler.metrics[:process_unique_memory_bytes]).to receive(:set).with({}, 9000)
expect(sampler.metrics[:process_proportional_memory_bytes]).to receive(:set).with({}, 10_000)
sampler.sample
end
......
......@@ -3,33 +3,122 @@
require 'spec_helper'
describe Gitlab::Metrics::System do
if File.exist?('/proc')
context 'when /proc files exist' do
# Fixtures pulled from:
# Linux carbon 5.3.0-7648-generic #41~1586789791~19.10~9593806-Ubuntu SMP Mon Apr 13 17:50:40 UTC x86_64 x86_64 x86_64 GNU/Linux
let(:proc_status) do
# most rows omitted for brevity
<<~SNIP
Name: less
VmHWM: 2468 kB
VmRSS: 2468 kB
RssAnon: 260 kB
SNIP
end
let(:proc_smaps_rollup) do
# full snapshot
<<~SNIP
Rss: 2564 kB
Pss: 503 kB
Pss_Anon: 312 kB
Pss_File: 191 kB
Pss_Shmem: 0 kB
Shared_Clean: 2100 kB
Shared_Dirty: 0 kB
Private_Clean: 152 kB
Private_Dirty: 312 kB
Referenced: 2564 kB
Anonymous: 312 kB
LazyFree: 0 kB
AnonHugePages: 0 kB
ShmemPmdMapped: 0 kB
Shared_Hugetlb: 0 kB
Private_Hugetlb: 0 kB
Swap: 0 kB
SwapPss: 0 kB
Locked: 0 kB
SNIP
end
let(:proc_limits) do
# full snapshot
<<~SNIP
Limit Soft Limit Hard Limit Units
Max cpu time unlimited unlimited seconds
Max file size unlimited unlimited bytes
Max data size unlimited unlimited bytes
Max stack size 8388608 unlimited bytes
Max core file size 0 unlimited bytes
Max resident set unlimited unlimited bytes
Max processes 126519 126519 processes
Max open files 1024 1048576 files
Max locked memory 67108864 67108864 bytes
Max address space unlimited unlimited bytes
Max file locks unlimited unlimited locks
Max pending signals 126519 126519 signals
Max msgqueue size 819200 819200 bytes
Max nice priority 0 0
Max realtime priority 0 0
Max realtime timeout unlimited unlimited us
SNIP
end
describe '.memory_usage' do
it "returns the process' memory usage in bytes" do
expect(described_class.memory_usage).to be > 0
it "returns the process' resident set size (RSS) in bytes" do
mock_existing_proc_file('/proc/self/status', proc_status)
expect(described_class.memory_usage).to eq(2527232)
end
end
describe '.file_descriptor_count' do
it 'returns the amount of open file descriptors' do
expect(described_class.file_descriptor_count).to be > 0
expect(Dir).to receive(:glob).and_return(['/some/path', '/some/other/path'])
expect(described_class.file_descriptor_count).to eq(2)
end
end
describe '.max_open_file_descriptors' do
it 'returns the max allowed open file descriptors' do
expect(described_class.max_open_file_descriptors).to be > 0
mock_existing_proc_file('/proc/self/limits', proc_limits)
expect(described_class.max_open_file_descriptors).to eq(1024)
end
end
describe '.memory_usage_uss_pss' do
it "returns the process' unique and porportional set size (USS/PSS) in bytes" do
mock_existing_proc_file('/proc/self/smaps_rollup', proc_smaps_rollup)
# (Private_Clean (152 kB) + Private_Dirty (312 kB) + Private_Hugetlb (0 kB)) * 1024
expect(described_class.memory_usage_uss_pss).to eq(uss: 475136, pss: 515072)
end
end
else
end
context 'when /proc files do not exist' do
before do
mock_missing_proc_file
end
describe '.memory_usage' do
it 'returns 0.0' do
expect(described_class.memory_usage).to eq(0.0)
it 'returns 0' do
expect(described_class.memory_usage).to eq(0)
end
end
describe '.memory_usage_uss_pss' do
it "returns 0 for all components" do
expect(described_class.memory_usage_uss_pss).to eq(uss: 0, pss: 0)
end
end
describe '.file_descriptor_count' do
it 'returns 0' do
expect(Dir).to receive(:glob).and_return([])
expect(described_class.file_descriptor_count).to eq(0)
end
end
......@@ -98,4 +187,12 @@ describe Gitlab::Metrics::System do
expect(described_class.thread_cpu_duration(start_time)).to be_nil
end
end
def mock_existing_proc_file(path, content)
allow(File).to receive(:foreach).with(path) { |_path, &block| content.each_line(&block) }
end
def mock_missing_proc_file
allow(File).to receive(:foreach).and_raise(Errno::ENOENT)
end
end
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