Adds ruby and unicorn instrumentation

This adds ruby and unicorn instrumentation. This was originally
intended in 11.11 but due to performance concerns it was reverted. This
new commit foregoes the sys-proctable gem was causing performance issues
previously.

1 files changed, 26 insertions, 0 deletions

diff --git a/lib/gitlab/metrics/system.rb b/lib/gitlab/metrics/system.rb
index 426496855e3..d3cbd200584 100644
--- a/lib/gitlab/metrics/system.rb
+++ b/lib/gitlab/metrics/system.rb
@@ -23,6 +23,20 @@ module Gitlab
         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]
+
+          match[1].to_i
+        end
+
+        def self.process_start_time
+          fields = File.read('/proc/self/stat').split
+
+          ( fields[21].to_i || 0 ) / clk_tck
+        end
       else
         def self.memory_usage
           0.0
@@ -31,6 +45,14 @@ module Gitlab
         def self.file_descriptor_count
           0
         end
+
+        def self.max_open_file_descriptors
+          0
+        end
+
+        def self.process_start_time
+          0
+        end
       end
 
       # THREAD_CPUTIME is not supported on OS X
@@ -59,6 +81,10 @@ module Gitlab
       def self.monotonic_time
         Process.clock_gettime(Process::CLOCK_MONOTONIC, :float_second)
       end
+
+      def self.clk_tck
+        @clk_tck ||= `genconf CLK_TCK`.to_i
+      end
     end
   end
 end