Write to InfluxDB directly via UDP

This removes the need for Sidekiq and any overhead/problems introduced
by TCP. There are a few things to take into account:

1. When writing data to InfluxDB you may still get an error if the
   server becomes unavailable during the write. Because of this we're
   catching all exceptions and just ignore them (for now).
2. Writing via UDP apparently requires the timestamp to be in
   nanoseconds. Without this data either isn't written properly.
3. Due to the restrictions on UDP buffer sizes we're writing metrics one
   by one, instead of writing all of them at once.

1 files changed, 0 insertions, 52 deletions

diff --git a/spec/workers/metrics_worker_spec.rb b/spec/workers/metrics_worker_spec.rb
deleted file mode 100644
index 18260ea0c24..00000000000
--- a/spec/workers/metrics_worker_spec.rb
+++ /dev/null
@@ -1,52 +0,0 @@
-require 'spec_helper'
-
-describe MetricsWorker do
-  let(:worker) { described_class.new }
-
-  describe '#perform' do
-    it 'prepares and writes the metrics to InfluxDB' do
-      connection = double(:connection)
-      pool       = double(:pool)
-
-      expect(pool).to receive(:with).and_yield(connection)
-      expect(connection).to receive(:write_points).with(an_instance_of(Array))
-      expect(Gitlab::Metrics).to receive(:pool).and_return(pool)
-
-      worker.perform([{ 'series' => 'kittens', 'tags' => {} }])
-    end
-  end
-
-  describe '#prepare_metrics' do
-    it 'returns a Hash with the keys as Symbols' do
-      metrics = worker.prepare_metrics([{ 'values' => {}, 'tags' => {} }])
-
-      expect(metrics).to eq([{ values: {}, tags: {} }])
-    end
-
-    it 'escapes tag values' do
-      metrics = worker.prepare_metrics([
-        { 'values' => {}, 'tags' => { 'foo' => 'bar=' } }
-      ])
-
-      expect(metrics).to eq([{ values: {}, tags: { 'foo' => 'bar\\=' } }])
-    end
-
-    it 'drops empty tags' do
-      metrics = worker.prepare_metrics([
-        { 'values' => {}, 'tags' => { 'cats' => '', 'dogs' => nil } }
-      ])
-
-      expect(metrics).to eq([{ values: {}, tags: {} }])
-    end
-  end
-
-  describe '#escape_value' do
-    it 'escapes an equals sign' do
-      expect(worker.escape_value('foo=')).to eq('foo\\=')
-    end
-
-    it 'casts values to Strings' do
-      expect(worker.escape_value(10)).to eq('10')
-    end
-  end
-end