Add Puma.stats_hash

Change Puma.stats to Puma.stats_json to help disambiguate. An alias is provided for backwards compatibility

Having access to the hash allows to produce stats in other ways (such as StatsD) without having to parse JSON of data that is available in memory. An example of this workaround is https://github.com/yob/puma-plugin-statsd/blob/fa6ba1f5074473618643ef7cf99747801a001dec/lib/puma/plugin/statsd.rb#L112-L114

History.md

@@ -3,6 +3,7 @@
 * Features
   * Add pumactl `thread-backtraces` command to print thread backtraces (#2053)
   * Configuration: `environment` is read from `RAILS_ENV`, if `RACK_ENV` can't be found (#2022)
+  * `Puma.stats` was renamed to `Puma.stats_json`, `Puma.stats_hash` has been added to provide the same data as a Hash
 
 * Bugfixes
   * Your bugfix goes here (#Github Number)

lib/puma.rb

@@ -19,10 +19,16 @@ def self.stats_object=(val)
     @get_stats = val
   end
 
-  def self.stats
-    @get_stats.stats
+  def self.stats_hash
+    @get_stats.stats_hash
   end
 
+
+  def self.stats_json
+    @get_stats.stats_json
+  end
+  singleton_class.alias_method :stats, :stats_json
+
   # Thread name is new in Ruby 2.3
   def self.set_thread_name(name)
     return unless Thread.current.respond_to?(:name=)

lib/puma/app/status.rb

@@ -54,7 +54,7 @@ def call(env)
           rack_response(200, GC.stat.to_json)
 
         when /\/stats$/
-          rack_response(200, @cli.stats)
+          rack_response(200, @cli.stats_json)
 
         when /\/thread-backtraces$/
           backtraces = []

lib/puma/cluster.rb

@@ -350,12 +350,36 @@ def reload_worker_directory
 
     # Inside of a child process, this will return all zeroes, as @workers is only populated in
     # the master process.
-    def stats
+    def stats_hash
       old_worker_count = @workers.count { |w| w.phase != @phase }
-      booted_worker_count = @workers.count { |w| w.booted? }
-      worker_status = '[' + @workers.map { |w| %Q!{ "started_at": "#{w.started_at.utc.iso8601}", "pid": #{w.pid}, "index": #{w.index}, "phase": #{w.phase}, "booted": #{w.booted?}, "last_checkin": "#{w.last_checkin.utc.iso8601}", "last_status": #{w.last_status} }!}.join(",") + ']'
-      %Q!{ "started_at": "#{@started_at.utc.iso8601}", "workers": #{@workers.size}, "phase": #{@phase}, "booted_workers": #{booted_worker_count}, "old_workers": #{old_worker_count}, "worker_status": #{worker_status} }!
+      worker_status = @workers.map do |w|
+        {
+          started_at: w.started_at.utc.iso8601,
+          pid: w.pid,
+          index: w.index,
+          phase: w.phase,
+          booted: w.booted?,
+          last_checkin: w.last_checkin.utc.iso8601,
+          last_status: w.last_status,
+        }
+      end
+
+      {
+        started_at: @started_at.utc.iso8601,
+        workers: @workers.size,
+        phase: @phase,
+        booted_workers: worker_status.count { |w| w[:booted] },
+        old_workers: old_worker_count,
+        worker_status: worker_status,
+      }
+    end
+
+    def stats_json
+      h = stats_hash
+      worker_status = '[' + h[:worker_status].map { |w| %Q!{ "started_at": "#{w[:started_at]}", "pid": #{w[:pid]}, "index": #{w[:index]}, "phase": #{w[:phase]}, "booted": #{w[:booted]}, "last_checkin": "#{w[:last_checkin]}", "last_status": #{w[:last_status]} }!}.join(",") + ']'
+      %Q!{ "started_at": "#{h[:started_at]}", "workers": #{h[:workers]}, "phase": #{h[:phase]}, "booted_workers": #{h[:booted_workers]}, "old_workers": #{h[:old_workers]}, "worker_status": #{worker_status} }!
     end
+    #alias_method :stats, :stats_json
 
     def preload?
       @options[:preload_app]

lib/puma/launcher.rb

@@ -95,10 +95,15 @@ def initialize(conf, launcher_args={})
     attr_reader :binder, :events, :config, :options, :restart_dir
 
     # Return stats about the server
-    def stats
-      @runner.stats
+    def stats_hash
+      @runner.stats_hash
     end
 
+    def stats_json
+      @runner.stats_json
+    end
+    alias_method :stats, :stats_json
+
     # Write a state file that can be used by pumactl to control
     # the server
     def write_state

lib/puma/single.rb

@@ -13,14 +13,22 @@ module Puma
   # gets created via the `start_server` method from the `Puma::Runner` class
   # that this inherits from.
   class Single < Runner
-    def stats
-      b = @server.backlog || 0
-      r = @server.running || 0
-      t = @server.pool_capacity || 0
-      m = @server.max_threads || 0
-      %Q!{ "started_at": "#{@started_at.utc.iso8601}", "backlog": #{b}, "running": #{r}, "pool_capacity": #{t}, "max_threads": #{m} }!
+    def stats_hash
+      {
+        started_at: @started_at.utc.iso8601,
+        backlog: @server.backlog || 0,
+        running: @server.running || 0,
+        pool_capacity: @server.pool_capacity || 0,
+        max_threads: @server.max_threads || 0,
+      }
     end
 
+    def stats_json
+      h = stats_hash
+      %Q!{ "started_at": "#{h[:started_at]}", "backlog": #{h[:backlog]}, "running": #{h[:running]}, "pool_capacity": #{h[:pool_capacity]}, "max_threads": #{h[:max_threads]} }!
+    end
+    alias_method :stats, :stats_json
+
     def restart
       @server.begin_restart
     end

test/test_app_status.rb

@@ -23,7 +23,7 @@ def halt
       @status = :halt
     end
 
-    def stats
+    def stats_json
       "{}"
     end
   end

test/test_cli.rb

@@ -58,7 +58,8 @@ def test_control_for_tcp
     s.close
 
     assert_match(/{ "started_at": "\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}Z", "backlog": 0, "running": 0, "pool_capacity": 16, "max_threads": 16 }/, body.split(/\r?\n/).last)
-    assert_match(/{ "started_at": "\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}Z", "backlog": 0, "running": 0, "pool_capacity": 16, "max_threads": 16 }/, Puma.stats)
+    assert_match(/{ "started_at": "\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}Z", "backlog": 0, "running": 0, "pool_capacity": 16, "max_threads": 16 }/, Puma.stats_json)
+    assert_equal([:started_at, :backlog, :running, :pool_capacity, :max_threads], Puma.stats_hash.keys)
 
   ensure
     cli.launcher.stop
@@ -94,7 +95,8 @@ def test_control_for_ssl
 
     expected_stats = /{ "started_at": "\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}Z", "backlog": 0, "running": 0, "pool_capacity": 16, "max_threads": 16 }/
     assert_match(expected_stats, body.split(/\r?\n/).last)
-    assert_match(expected_stats, Puma.stats)
+    assert_match(expected_stats, Puma.stats_json)
+    assert_equal([:started_at, :backlog, :running, :pool_capacity, :max_threads], Puma.stats_hash.keys)
 
   ensure
     cli.launcher.stop