Use monotonic time to avoid time issues while benchmarking

Leap Seconds, time zone changes, clock syncing can all mess with
results/make time jump backwards or forward. Monotonic time
is monotonically increasing and hence not prone to these
problems.

Bit longer explanation here: https://stackoverflow.com/a/45483168

Author: PragTob

profile/benchmarking/complex.rb

@@ -48,15 +48,15 @@ def index_documents(opts = {})
         end
 
         with_cleanup do
-          start = Time.now
+          start = Process.clock_gettime(Process::CLOCK_MONOTONIC)
           results = measured_repetitions.times.collect do
             Benchmark.realtime do
               slices.each do |slice|
                 client.bulk(body: slice)
               end
             end
           end
-          end_time = Time.now
+          end_time = Process.clock_gettime(Process::CLOCK_MONOTONIC)
           results
         end
 
@@ -96,13 +96,13 @@ def search_documents(opts = {})
             client.search(request)
           end
 
-          start = Time.now
+          start = Process.clock_gettime(Process::CLOCK_MONOTONIC)
           results = measured_repetitions.times.collect do
             Benchmark.realtime do
               client.search(request)
             end
           end
-          end_time = Time.now
+          end_time = Process.clock_gettime(Process::CLOCK_MONOTONIC)
           results
         end
 

profile/benchmarking/simple.rb

@@ -46,14 +46,14 @@ def ping(opts = {})
         warmup_repetitions.times { client.ping }
 
         results = measured_repetitions.times.collect do
-          start = Time.now
+          start = Process.clock_gettime(Process::CLOCK_MONOTONIC)
           Benchmark.realtime do
             action_iterations.times do
               client.ping
             end
           end
         end
-        end_time = Time.now
+        end_time = Process.clock_gettime(Process::CLOCK_MONOTONIC)
 
         options = { duration: end_time - start,
                     operation: __method__,
@@ -82,15 +82,15 @@ def create_index(opts = {})
         end
 
         with_cleanup do
-          start = Time.now
+          start = Process.clock_gettime(Process::CLOCK_MONOTONIC)
           results = measured_repetitions.times.collect do
             Benchmark.realtime do
               action_iterations.times do
                 client.indices.create(index: "benchmarking-#{Time.now.to_f}")
               end
             end
           end
-          end_time = Time.now
+          end_time = Process.clock_gettime(Process::CLOCK_MONOTONIC)
           results
         end
 
@@ -122,15 +122,15 @@ def index_document_small(opts={})
         end
 
         with_cleanup do
-          start = Time.now
+          start = Process.clock_gettime(Process::CLOCK_MONOTONIC)
           results = measured_repetitions.times.collect do
             Benchmark.realtime do
               action_iterations.times do
                 client.create(index: INDEX, body: document)
               end
             end
           end
-          end_time = Time.now
+          end_time = Process.clock_gettime(Process::CLOCK_MONOTONIC)
           results
         end
 
@@ -165,15 +165,15 @@ def index_document_large(opts={})
         end
 
         with_cleanup do
-          start = Time.now
+          start = Process.clock_gettime(Process::CLOCK_MONOTONIC)
           results = measured_repetitions.times.collect do
             Benchmark.realtime do
               action_iterations.times do
                 client.create(index: INDEX, body: document)
               end
             end
           end
-          end_time = Time.now
+          end_time = Process.clock_gettime(Process::CLOCK_MONOTONIC)
           results
         end
 
@@ -208,15 +208,15 @@ def get_document_small(opts={})
             client.get(index: INDEX, id: id)
           end
 
-          start = Time.now
+          start = Process.clock_gettime(Process::CLOCK_MONOTONIC)
           results = measured_repetitions.times.collect do
             Benchmark.realtime do
               action_iterations.times do
                 client.get(index: INDEX, id: id)
               end
             end
           end
-          end_time = Time.now
+          end_time = Process.clock_gettime(Process::CLOCK_MONOTONIC)
           results
         end
 
@@ -251,15 +251,15 @@ def get_document_large(opts={})
             client.get(index: INDEX, id: id)
           end
 
-          start = Time.now
+          start = Process.clock_gettime(Process::CLOCK_MONOTONIC)
           results = measured_repetitions.times.collect do
             Benchmark.realtime do
               action_iterations.times do
                 client.get(index: INDEX, id: id)
               end
             end
           end
-          end_time = Time.now
+          end_time = Process.clock_gettime(Process::CLOCK_MONOTONIC)
         end
 
         options = { duration: end_time - start,
@@ -301,15 +301,15 @@ def search_document_small(opts={})
             client.search(request)
           end
 
-          start = Time.now
+          start = Process.clock_gettime(Process::CLOCK_MONOTONIC)
           results = measured_repetitions.times.collect do
             Benchmark.realtime do
               action_iterations.times do
                 client.search(request)
               end
             end
           end
-          end_time = Time.now
+          end_time = Process.clock_gettime(Process::CLOCK_MONOTONIC)
         end
 
         options = { duration: end_time - start,
@@ -350,15 +350,15 @@ def search_document_large(opts={})
             client.search(request)
           end
 
-          start = Time.now
+          start = Process.clock_gettime(Process::CLOCK_MONOTONIC)
           results = measured_repetitions.times.collect do
             Benchmark.realtime do
               action_iterations.times do
                 client.search(request)
               end
             end
           end
-          end_time = Time.now
+          end_time = Process.clock_gettime(Process::CLOCK_MONOTONIC)
           results
         end
 
@@ -398,7 +398,7 @@ def update_document(opts={})
                           body: { doc: { field:  "#{document[field]}-#{i}" } })
           end
 
-          start = Time.now
+          start = Process.clock_gettime(Process::CLOCK_MONOTONIC)
           results = measured_repetitions.times.collect do
             Benchmark.realtime do
               action_iterations.times do |i|
@@ -408,7 +408,7 @@ def update_document(opts={})
               end
             end
           end
-          end_time = Time.now
+          end_time = Process.clock_gettime(Process::CLOCK_MONOTONIC)
           results
         end