From a3cf3d19826ea1e67381592f2d91f7041cccc222 Mon Sep 17 00:00:00 2001 From: Yorick Peterse Date: Mon, 4 Apr 2016 12:47:10 +0200 Subject: [PATCH 1/3] Corrected some spec headers for Gitlab::Metrics --- spec/lib/gitlab/metrics_spec.rb | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/spec/lib/gitlab/metrics_spec.rb b/spec/lib/gitlab/metrics_spec.rb index 0ec8a6dc5cb..93dd958168d 100644 --- a/spec/lib/gitlab/metrics_spec.rb +++ b/spec/lib/gitlab/metrics_spec.rb @@ -13,7 +13,7 @@ describe Gitlab::Metrics do end end - describe '#submit_metrics' do + describe '.submit_metrics' do it 'prepares and writes the metrics to InfluxDB' do connection = double(:connection) pool = double(:pool) @@ -26,7 +26,7 @@ describe Gitlab::Metrics do end end - describe '#prepare_metrics' do + describe '.prepare_metrics' do it 'returns a Hash with the keys as Symbols' do metrics = described_class. prepare_metrics([{ 'values' => {}, 'tags' => {} }]) @@ -51,7 +51,7 @@ describe Gitlab::Metrics do end end - describe '#escape_value' do + describe '.escape_value' do it 'escapes an equals sign' do expect(described_class.escape_value('foo=')).to eq('foo\\=') end From 1af6cf28c031cec7813d3fc090476c088de57173 Mon Sep 17 00:00:00 2001 From: Yorick Peterse Date: Mon, 4 Apr 2016 14:00:35 +0200 Subject: [PATCH 2/3] Measure Ruby blocks using Gitlab::Metrics This allows measuring of timings of arbitrary Ruby blocks, this allows for more fine grained performance monitoring. Custom values and tags can also be attached to a block. --- lib/gitlab/metrics.rb | 26 +++++++++++++++++++++ spec/lib/gitlab/metrics_spec.rb | 41 +++++++++++++++++++++++++++++++++ 2 files changed, 67 insertions(+) diff --git a/lib/gitlab/metrics.rb b/lib/gitlab/metrics.rb index 88a265c6af2..4a3f47b5a95 100644 --- a/lib/gitlab/metrics.rb +++ b/lib/gitlab/metrics.rb @@ -70,6 +70,32 @@ module Gitlab value.to_s.gsub('=', '\\=') end + # Measures the execution time of a block. + # + # Example: + # + # Gitlab::Metrics.measure(:find_by_username_timings) do + # User.find_by_username(some_username) + # end + # + # series - The name of the series to store the data in. + # values - A Hash containing extra values to add to the metric. + # tags - A Hash containing extra tags to add to the metric. + # + # Returns the value yielded by the supplied block. + def self.measure(series, values = {}, tags = {}) + return yield unless Transaction.current + + start = Time.now.to_f + retval = yield + duration = (Time.now.to_f - start) * 1000.0 + values = values.merge(duration: duration) + + Transaction.current.add_metric(series, values, tags) + + retval + end + # When enabled this should be set before being used as the usual pattern # "@foo ||= bar" is _not_ thread-safe. if enabled? diff --git a/spec/lib/gitlab/metrics_spec.rb b/spec/lib/gitlab/metrics_spec.rb index 93dd958168d..8f63a5f2043 100644 --- a/spec/lib/gitlab/metrics_spec.rb +++ b/spec/lib/gitlab/metrics_spec.rb @@ -60,4 +60,45 @@ describe Gitlab::Metrics do expect(described_class.escape_value(10)).to eq('10') end end + + describe '.measure' do + context 'without a transaction' do + it 'returns the return value of the block' do + val = Gitlab::Metrics.measure(:foo) { 10 } + + expect(val).to eq(10) + end + end + + context 'with a transaction' do + let(:transaction) { Gitlab::Metrics::Transaction.new } + + before do + allow(Gitlab::Metrics::Transaction).to receive(:current). + and_return(transaction) + end + + it 'adds a metric to the current transaction' do + expect(transaction).to receive(:add_metric). + with(:foo, { duration: a_kind_of(Numeric) }, { tag: 'value' }) + + Gitlab::Metrics.measure(:foo, {}, tag: 'value') { 10 } + end + + it 'supports adding of custom values' do + values = { duration: a_kind_of(Numeric), number: 10 } + + expect(transaction).to receive(:add_metric). + with(:foo, values, { tag: 'value' }) + + Gitlab::Metrics.measure(:foo, { number: 10 }, tag: 'value') { 10 } + end + + it 'returns the return value of the block' do + val = Gitlab::Metrics.measure(:foo) { 10 } + + expect(val).to eq(10) + end + end + end end From 352bc7d2b9a4ed5725e4f0e9f2e63d71678de9bc Mon Sep 17 00:00:00 2001 From: Yorick Peterse Date: Tue, 5 Apr 2016 12:37:41 +0200 Subject: [PATCH 3/3] Added dev guide for measuring Ruby blocks --- doc/development/README.md | 1 + doc/development/instrumentation.md | 37 ++++++++++++++++++++++++++++++ 2 files changed, 38 insertions(+) create mode 100644 doc/development/instrumentation.md diff --git a/doc/development/README.md b/doc/development/README.md index 1b281809afc..8940b558fb6 100644 --- a/doc/development/README.md +++ b/doc/development/README.md @@ -4,6 +4,7 @@ - [CI setup](ci_setup.md) for testing GitLab - [Gotchas](gotchas.md) to avoid - [How to dump production data to staging](db_dump.md) +- [Instrumentation](instrumentation.md) - [Migration Style Guide](migration_style_guide.md) for creating safe migrations - [Rake tasks](rake_tasks.md) for development - [Shell commands](shell_commands.md) in the GitLab codebase diff --git a/doc/development/instrumentation.md b/doc/development/instrumentation.md new file mode 100644 index 00000000000..c0192bd6709 --- /dev/null +++ b/doc/development/instrumentation.md @@ -0,0 +1,37 @@ +# Instrumenting Ruby Code + +GitLab Performance Monitoring allows instrumenting of custom blocks of Ruby +code. This can be used to measure the time spent in a specific part of a larger +chunk of code. The resulting data is written to a separate series. + +To start measuring a block of Ruby code you should use +`Gitlab::Metrics.measure` and give it a name for the series to store the data +in: + +```ruby +Gitlab::Metrics.measure(:user_logins) do + ... +end +``` + +The first argument of this method is the series name and should be plural. This +name will be prefixed with `rails_` or `sidekiq_` depending on whether the code +was run in the Rails application or one of the Sidekiq workers. In the +above example the final series names would be as follows: + +- rails_user_logins +- sidekiq_user_logins + +Series names should be plural as this keeps the naming style in line with the +other series names. + +By default metrics measured using a block contain a single value, "duration", +which contains the number of milliseconds it took to execute the block. Custom +values can be added by passing a Hash as the 2nd argument. Custom tags can be +added by passing a Hash as the 3rd argument. A simple example is as follows: + +```ruby +Gitlab::Metrics.measure(:example_series, { number: 10 }, { class: self.class.to_s }) do + ... +end +```