LeakProfiler

This is a Ruby gem for profiling memory leaks in Ruby applications. It provides tools to help identify and analyze memory usage patterns, making it easier to find and fix memory leaks.

Installation

Install the gem and add to the application's Gemfile by executing:

bundle add leak_profiler

If bundler is not being used to manage dependencies, install the gem by executing:

gem install leak_profiler

Usage

require 'leak_profiler'

LeakProfiler.new.report.report_rss

# ... your code that may have memory leaks ...

LeakProfiler#new

• Arguments:
  • output_dir (default ./leak_profiler): Specify the output directory for report.

LeakProfiler#report

This method outputs where the object was allocated and where it is referenced, like:

Allocations ================================================================================
/home/watson/src/fluentd/lib/fluent/plugin_helper/thread.rb:70 retains 1098464 bytes, allocations 165 objects
/home/watson/src/fluentd/lib/fluent/plugin/metrics_local.rb:58 retains 56400 bytes, allocations 50 objects
/home/watson/.rbenv/versions/3.4.2/lib/ruby/3.4.0/open3.rb:534 retains 50080 bytes, allocations 544 objects
/home/watson/src/fluentd/lib/fluent/msgpack_factory.rb:105 retains 44400 bytes, allocations 50 objects
/home/watson/.rbenv/versions/3.4.2/lib/ruby/site_ruby/3.4.0/rubygems/specification.rb:1093 retains 43846 bytes, allocations 409 objects
/home/watson/src/fluentd/lib/fluent/plugin.rb:181 retains 40960 bytes, allocations 23 objects
/home/watson/src/fluentd/lib/fluent/msgpack_factory.rb:99 retains 36000 bytes, allocations 200 objects
/home/watson/.rbenv/versions/3.4.2/lib/ruby/3.4.0/open3.rb:535 retains 29400 bytes, allocations 49 objects
/home/watson/.rbenv/versions/3.4.2/lib/ruby/gems/3.4.0/gems/csv-3.3.3/lib/csv/writer.rb:154 retains 26820 bytes, allocations 56 objects
/home/watson/.rbenv/versions/3.4.2/lib/ruby/gems/3.4.0/gems/csv-3.3.3/lib/csv.rb:2983 retains 26560 bytes, allocations 61 objects
Referrers --------------------------------------------------------------------------------
/home/watson/src/fluentd/lib/fluent/plugin_helper/thread.rb:70 object is referred at:
    Fiber (allocated at /home/watson/src/fluentd/lib/fluent/plugin/metrics_local.rb:58)
    NameError::message (allocated at /home/watson/.rbenv/versions/3.4.2/lib/ruby/3.4.0/open3.rb:534)
    NoMethodError (allocated at /home/watson/.rbenv/versions/3.4.2/lib/ruby/3.4.0/open3.rb:534)
    Fluent::PluginHelper::ChildProcess::ProcessInfo (allocated at /home/watson/src/fluentd/lib/fluent/plugin_helper/child_process.rb:355)
    Hash (allocated at /home/watson/src/fluentd/lib/fluent/plugin/formatter_csv.rb:55)
...

Allocations: This section lists the locations in the code where object was allocated, along with the size of the allocation and the number of objects allocated.

Referrers: This section lists the locations in the code where the object is referenced.

• Arguments:
  • interval (default 30): The interval in seconds for report.
  • max_allocations (default 10): Outputs the specified number of objects that use a lot of memory.
  • max_referrers (default 3): Outputs the number of references in order of the amount of memory used.
  • report (defalut nil): Specify the logger object if you want to use custom logger.

LeakProfiler#report_rss

This method outputs the RSS (Resident Set Size) of the process with CSV format, like:

elapsed [sec],memory usage (rss) [MB]
0,47.20703125
1,53.40234375
2,55.02734375
3,55.90234375

• Arguments:
  • interval (default 1): The interval in seconds for report.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/Watson1978/leak_profiler.