Update docs and calculate process start time via proc table

This updates monitor docs to reflect the new ruby and unicorn metrics as
well as making it so we fetch process start time via the proc table
instead of via CLOCK_BOOTTIME

2 files changed, 15 insertions, 9 deletions

diff --git a/spec/lib/gitlab/metrics/samplers/ruby_sampler_spec.rb b/spec/lib/gitlab/metrics/samplers/ruby_sampler_spec.rb
index 0fafcb8e380..aaf8c9fa2a0 100644
--- a/spec/lib/gitlab/metrics/samplers/ruby_sampler_spec.rb
+++ b/spec/lib/gitlab/metrics/samplers/ruby_sampler_spec.rb
@@ -20,10 +20,10 @@ describe Gitlab::Metrics::Samplers::RubySampler do
       sampler.sample
     end
 
-    it 'adds a metric containing the memory usage' do
+    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[:memory_usage]).to receive(:set).with({}, 9000)
+      expect(sampler.metrics[:process_resident_memory_bytes]).to receive(:set).with({}, 9000)
 
       sampler.sample
     end
@@ -37,7 +37,7 @@ describe Gitlab::Metrics::Samplers::RubySampler do
       sampler.sample
     end
 
-    it 'adds a metric containing the processes total cpu time' do
+    it 'adds a metric containing the process total cpu time' do
       expect(Gitlab::Metrics::System).to receive(:cpu_time).and_return(0.51)
       expect(sampler.metrics[:process_cpu_seconds_total]).to receive(:set).with({}, 0.51)
 
diff --git a/spec/lib/gitlab/metrics/system_spec.rb b/spec/lib/gitlab/metrics/system_spec.rb
index 2de6821bb79..b0603d96eb2 100644
--- a/spec/lib/gitlab/metrics/system_spec.rb
+++ b/spec/lib/gitlab/metrics/system_spec.rb
@@ -19,6 +19,12 @@ describe Gitlab::Metrics::System do
         expect(described_class.max_open_file_descriptors).to be > 0
       end
     end
+
+    describe '.process_start_time' do
+      it 'returns the process start time' do
+        expect(described_class.process_start_time).to be > 0
+      end
+    end
   else
     describe '.memory_usage' do
       it 'returns 0.0' do
@@ -37,6 +43,12 @@ describe Gitlab::Metrics::System do
         expect(described_class.max_open_file_descriptors).to eq(0)
       end
     end
+
+    describe 'process_start_time' do
+      it 'returns 0' do
+        expect(described_class.process_start_time).to eq(0)
+      end
+    end
   end
 
   describe '.cpu_time' do
@@ -56,10 +68,4 @@ describe Gitlab::Metrics::System do
       expect(described_class.monotonic_time).to be_an(Float)
     end
   end
-
-  describe '.process_start_time' do
-    it 'returns a Float' do
-      expect(described_class.process_start_time).to be_an(Float)
-    end
-  end
 end