Profiling and monitoring ruby & rails applications
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The document discusses profiling and monitoring Ruby on Rails applications. It provides examples of using the ruby-prof gem to profile a Ruby script and identify bottlenecks. It also discusses using NewRelic to monitor production applications and track metrics like web transactions, SQL queries, background jobs, and errors. Common performance issues mentioned include the N+1 query problem, lack of indexing, unnecessary ActiveRecord loading, default GC parameters, and unknown abstraction internals.
Profiling and monitoring ruby & rails applications
- 1. Profiling and monitoring ruby/rails JÁN SUCHAL @JSUCHAL
- 2. Optimalization “If you can’t measure it, you can’t improve it.” – Lord Kelvin Environment development vs. production (hw, sw, load) data (synthetic vs. real) Bottlenecks 10sec * 1 run vs. 0.5s * 100 runs run time * runs vs. development time Microbenchmarks waste of time vs. 20 * 1% = 20% “There are three kinds of lies: lies, damned lies, and statistics.” – Benjamin Disraeli single run vs. multiple runs average vs. standard deviance, percentiles cold vs. hot cache
- 3. Profiler - Example # profiler/dates.rb require 'date' def create_days_after(date_str, n) after = Date.strptime(date_str) + n after.strftime("%Y-%m-%d") end 1000.times do create_days_after("1982-10-27", 5) end
- 4. Ruby Profiler $ gem install ruby-prof $ ruby-prof dates.rb How long does each method take? $ ruby-prof dates.rb –m 3 Just methods above 3% time Thread ID: 7749480 Total: 0.653076 %self total self wait child calls name 12.97 0.19 0.08 0.00 0.18 2000 String#scan 11.57 0.08 0.08 0.00 0.00 205000 String#=== 6.87 0.18 0.04 0.00 0.14 1000 String#gsub 6.28 0.05 0.04 0.00 0.01 14000 Hash#values_at 4.08 0.03 0.03 0.00 0.00 80470 Hash#default 3.21 0.03 0.02 0.00 0.01 3000 Date#emit
- 5. Ruby Profiler Thread ID: 7749480 Total: 0.653076 %self total self wait child calls name 12.97 0.19 0.08 0.00 0.18 2000 String#scan 11.57 0.08 0.08 0.00 0.00 205000 String#=== 6.87 0.18 0.04 0.00 0.14 1000 String#gsub 6.28 0.05 0.04 0.00 0.01 14000 Hash#values_at 4.08 0.03 0.03 0.00 0.00 80470 Hash#default 3.21 0.03 0.02 0.00 0.01 3000 Date#emit total – time in method and children calls self – time in method call wait – wait time child – time in child calls call – number of times method invoked
- 6. Ruby Profiler $ ruby-prof dates.rb -m 3 -p graph Which method calls what and how many times? Thread ID: 15523700 Total Time: 0.675587048 %total %self total self wait child calls Name 0.20 0.10 0.00 0.20 2000/2000 <Class::Date>#_strptime_i 30.28% 14.70% 0.20 0.10 0.00 0.20 2000 String#scan 0.04 0.04 0.00 0.00 110000/205000 String#=== 0.02 0.01 0.00 0.01 3000/5000 Date::Format::Bag#method_... 0.02 0.00 0.00 0.01 2000/3005 Class#new 0.01 0.01 0.00 0.00 5000/5000 String#sub! 0.01 0.00 0.00 0.01 2000/2000 Range#=== 0.00 0.00 0.00 0.00 3000/3000 String#to_i 0.00 0.00 0.00 0.00 2000/2000 <Class::Regexp>#quote 0.00 0.00 0.00 0.00 2000/2000 Regexp#=== 0.00 0.00 0.00 0.00 1000/1000 <Class::Date>#num_pattern? 0.00 0.00 0.00 0.00 1000/2000 <Class::Date>#_strptime_i
- 7. Ruby Profiler Thread ID: 15523700 Total Time: 0.675587048 %total %self total self wait child calls Name 0.20 0.10 0.00 0.20 2000/2000 <Class::Date>#_strptime_i 30.28% 14.70% 0.20 0.10 0.00 0.20 2000 String#scan 0.04 0.04 0.00 0.00 110000/205000 String#=== 0.02 0.01 0.00 0.01 3000/5000 Date::Format::Bag#method_.. three parts parent calls method children calls calls – number of calls from method/total number of calls
- 8. Ruby Profiler $ ruby-prof dates.rb -p graph_html -m 3 > graph.html $ ruby-prof dates.rb -p graph_html -m 3 –s self > graph.html
- 9. Profiler - KCacheGrind $ ruby-prof dates.rb -p call_tree -m 3 > dates1.grind $ kcachegrind dates1.grind
- 10. benchmark-ips require 'benchmark/ips' require 'ostruct' require 'hashr' require 'hashugar' SMALL_HASH = {:a => 1, :b => 2} Benchmark.ips do |x| x.report 'OpenStruct create small hash and access once', 'OpenStruct.new(SMALL_HASH).item5' x.report 'Hashr create small hash and access once', 'Hashr.new(SMALL_HASH).item5' x.report 'Hashugar create small hash and access once', 'Hashugar.new(SMALL_HASH).item5‘ end OpenStruct create small hash and access once 43858.0 (±5.5%) i/s - 221820 in 5.074250s (cycle=3697) Hashr create small hash and access once 67408.9 (±5.0%) i/s - 339780 in 5.053728s (cycle=5663) Hashugar create small hash and access once 230217.9 (±4.2%) i/s - 1152670 in 5.015705s (cycle=15790)
- 11. Memory profiling Patched ruby $ rvm install 1.9.3 --patch railsexpress --name gc $ ruby-prof --mode=allocations dates.rb –m 3 %self total self wait child calls name 59.23 6004.00 6004.00 0.00 0.00 1000 <Class::Date>#strptime 9.87 1000.00 1000.00 0.00 0.00 1000 Date#strftime 9.87 9004.00 1000.00 0.00 8004.00 1000 Object#create_days_after 9.87 1000.00 1000.00 0.00 0.00 1000 Date#+ 9.87 10004.00 1000.00 0.00 9004.00 1 Integer#times
- 12. Rails / NewRelic Developer mode gem 'newrelic_rpm‘ http://localhost:3000/newrelic gem 'newrelic_rpm', git: 'git://github.com/jsuchal/rpm.git', branch: 'feature-profile-sorting'
- 14. Rails / NewRelic Developer mode
- 16. NewRelic Developer mode Profiler
- 17. Custom Method Tracers # initializers/elastic_search_traces.rb require 'new_relic/agent/method_tracer‘ ElasticSearch.class_eval do include NewRelic::Agent::MethodTracer add_method_tracer :search, 'Custom/elasticsearch/search' add_method_tracer :index, 'Custom/elasticsearch/index' end
- 18. NewRelic Production Monitoring Web Transactions – controller actions drilldown Transaction Traces – detailed slow requests Slow SQL – slow queries Background job monitoring Availabality monitoring Deployment tracking Scalability analysis ... Server monitoring (load, disks, …)
- 23. Error tracking ExceptionNotifier www.airbrake.io
- 24. Most common performance problems “1 + N query problem” joins FTW! Lack of proper indexing Unnecessary ActiveRecord loading e.g. count vs. size vs. length Default GC parameters 37signals params RUBY_HEAP_MIN_SLOTS=600000 # This is 60(!) times larger than default RUBY_GC_MALLOC_LIMIT=59000000 # This is 7 times larger than default RUBY_HEAP_FREE_MIN=100000 # This is 24 times larger than default Unknown abstraction internals e.g. OpenStruct