diff --git a/examples/puma/client-certs/run_server_with_certs.rb b/examples/puma/client-certs/run_server_with_certs.rb
index 6df57b67..22d7580d 100644
--- a/examples/puma/client-certs/run_server_with_certs.rb
+++ b/examples/puma/client-certs/run_server_with_certs.rb
@@ -8,8 +8,8 @@ app = proc {|env|
   p env['puma.peercert']
   [200, {}, [ env['puma.peercert'] ]]
 }
-events = Puma::Events.new($stdout, $stderr)
-server = Puma::Server.new(app, events)
+log_writer = Puma::LogWriter.new($stdout, $stderr)
+server = Puma::Server.new(app, log_writer)
 
 context = Puma::MiniSSL::Context.new
 context.key         = "certs/server.key"
diff --git a/lib/puma/binder.rb b/lib/puma/binder.rb
index 300ece14..67c58ee3 100644
--- a/lib/puma/binder.rb
+++ b/lib/puma/binder.rb
@@ -28,8 +28,8 @@ module Puma
 
     RACK_VERSION = [1,6].freeze
 
-    def initialize(events, conf = Configuration.new)
-      @events = events
+    def initialize(log_writer, conf = Configuration.new)
+      @log_writer = log_writer
       @conf = conf
       @listeners = []
       @inherited_fds = {}
@@ -38,7 +38,7 @@ module Puma
 
       @proto_env = {
         "rack.version".freeze => RACK_VERSION,
-        "rack.errors".freeze => events.stderr,
+        "rack.errors".freeze => log_writer.stderr,
         "rack.multithread".freeze => conf.options[:max_threads] > 1,
         "rack.multiprocess".freeze => conf.options[:workers] >= 1,
         "rack.run_once".freeze => false,
@@ -98,7 +98,7 @@ module Puma
     # @version 5.0.0
     #
     def create_activated_fds(env_hash)
-      @events.debug "ENV['LISTEN_FDS'] #{ENV['LISTEN_FDS'].inspect}  env_hash['LISTEN_PID'] #{env_hash['LISTEN_PID'].inspect}"
+      @log_writer.debug "ENV['LISTEN_FDS'] #{ENV['LISTEN_FDS'].inspect}  env_hash['LISTEN_PID'] #{env_hash['LISTEN_PID'].inspect}"
       return [] unless env_hash['LISTEN_FDS'] && env_hash['LISTEN_PID'].to_i == $$
       env_hash['LISTEN_FDS'].to_i.times do |index|
         sock = TCPServer.for_fd(socket_activation_fd(index))
@@ -110,7 +110,7 @@ module Puma
           [:tcp, addr, port]
         end
         @activated_sockets[key] = sock
-        @events.debug "Registered #{key.join ':'} for activation from LISTEN_FDS"
+        @log_writer.debug "Registered #{key.join ':'} for activation from LISTEN_FDS"
       end
       ["LISTEN_FDS", "LISTEN_PID"] # Signal to remove these keys from ENV
     end
@@ -152,17 +152,17 @@ module Puma
       end
     end
 
-    def parse(binds, logger, log_msg = 'Listening')
+    def parse(binds, log_writer, log_msg = 'Listening')
       binds.each do |str|
         uri = URI.parse str
         case uri.scheme
         when "tcp"
           if fd = @inherited_fds.delete(str)
             io = inherit_tcp_listener uri.host, uri.port, fd
-            logger.log "* Inherited #{str}"
+            log_writer.log "* Inherited #{str}"
           elsif sock = @activated_sockets.delete([ :tcp, uri.host, uri.port ])
             io = inherit_tcp_listener uri.host, uri.port, sock
-            logger.log "* Activated #{str}"
+            log_writer.log "* Activated #{str}"
           else
             ios_len = @ios.length
             params = Util.parse_query uri.query
@@ -174,7 +174,7 @@ module Puma
 
             @ios[ios_len..-1].each do |i|
               addr = loc_addr_str i
-              logger.log "* #{log_msg} on http://#{addr}"
+              log_writer.log "* #{log_msg} on http://#{addr}"
             end
           end
 
@@ -191,12 +191,12 @@ module Puma
           if fd = @inherited_fds.delete(str)
             @unix_paths << path unless abstract
             io = inherit_unix_listener path, fd
-            logger.log "* Inherited #{str}"
+            log_writer.log "* Inherited #{str}"
           elsif sock = @activated_sockets.delete([ :unix, path ]) ||
               @activated_sockets.delete([ :unix, File.realdirpath(path) ])
             @unix_paths << path unless abstract || File.exist?(path)
             io = inherit_unix_listener path, sock
-            logger.log "* Activated #{str}"
+            log_writer.log "* Activated #{str}"
           else
             umask = nil
             mode = nil
@@ -220,7 +220,7 @@ module Puma
 
             @unix_paths << path unless abstract || File.exist?(path)
             io = add_unix_listener path, umask, mode, backlog
-            logger.log "* #{log_msg} on #{str}"
+            log_writer.log "* #{log_msg} on #{str}"
           end
 
           @listeners << [str, io]
@@ -246,15 +246,15 @@ module Puma
                   params["#{v}_pem"] = @conf.options[:store][index]
                 end
               end
-              MiniSSL::ContextBuilder.new(params, @events).context
+              MiniSSL::ContextBuilder.new(params, @log_writer).context
             end
 
           if fd = @inherited_fds.delete(str)
-            logger.log "* Inherited #{str}"
+            log_writer.log "* Inherited #{str}"
             io = inherit_ssl_listener fd, ctx
           elsif sock = @activated_sockets.delete([ :tcp, uri.host, uri.port ])
             io = inherit_ssl_listener sock, ctx
-            logger.log "* Activated #{str}"
+            log_writer.log "* Activated #{str}"
           else
             ios_len = @ios.length
             backlog = params.fetch('backlog', 1024).to_i
@@ -262,20 +262,20 @@ module Puma
 
             @ios[ios_len..-1].each do |i|
               addr = loc_addr_str i
-              logger.log "* #{log_msg} on ssl://#{addr}?#{uri.query}"
+              log_writer.log "* #{log_msg} on ssl://#{addr}?#{uri.query}"
             end
           end
 
           @listeners << [str, io] if io
         else
-          logger.error "Invalid URI: #{str}"
+          log_writer.error "Invalid URI: #{str}"
         end
       end
 
       # If we inherited fds but didn't use them (because of a
       # configuration change), then be sure to close them.
       @inherited_fds.each do |str, fd|
-        logger.log "* Closing unused inherited connection: #{str}"
+        log_writer.log "* Closing unused inherited connection: #{str}"
 
         begin
           IO.for_fd(fd).close
@@ -295,7 +295,7 @@ module Puma
         fds = @ios.map(&:to_i)
         @activated_sockets.each do |key, sock|
           next if fds.include? sock.to_i
-          logger.log "* Closing unused activated socket: #{key.first}://#{key[1..-1].join ':'}"
+          log_writer.log "* Closing unused activated socket: #{key.first}://#{key[1..-1].join ':'}"
           begin
             sock.close
           rescue SystemCallError
@@ -319,7 +319,7 @@ module Puma
         local_certificates_path = File.expand_path("~/.localhost")
         [File.join(local_certificates_path, "localhost.key"), File.join(local_certificates_path, "localhost.crt")]
       end
-      MiniSSL::ContextBuilder.new({ "key" => key_path, "cert" => crt_path }, @events).context
+      MiniSSL::ContextBuilder.new({ "key" => key_path, "cert" => crt_path }, @log_writer).context
     end
 
     # Tell the server to listen on host +host+, port +port+.
diff --git a/lib/puma/cli.rb b/lib/puma/cli.rb
index 16e0ace6..fa8cc866 100644
--- a/lib/puma/cli.rb
+++ b/lib/puma/cli.rb
@@ -7,7 +7,7 @@ require 'puma'
 require 'puma/configuration'
 require 'puma/launcher'
 require 'puma/const'
-require 'puma/events'
+require 'puma/log_writer'
 
 module Puma
   class << self
@@ -30,10 +30,10 @@ module Puma
     # +stdout+ and +stderr+ can be set to IO-like objects which
     # this object will report status on.
     #
-    def initialize(argv, events=Events.stdio)
+    def initialize(argv, log_writer = LogWriter.stdio, events = Events.new)
       @debug = false
       @argv = argv.dup
-
+      @log_writer = log_writer
       @events = events
 
       @conf = nil
@@ -69,7 +69,7 @@ module Puma
         end
       end
 
-      @launcher = Puma::Launcher.new(@conf, :events => @events, :argv => argv)
+      @launcher = Puma::Launcher.new(@conf, :log_writer => @log_writer, :events => @events, :argv => argv)
     end
 
     attr_reader :launcher
@@ -83,7 +83,7 @@ module Puma
 
     private
     def unsupported(str)
-      @events.error(str)
+      @log_writer.error(str)
       raise UnsupportedOption
     end
 
@@ -186,7 +186,7 @@ module Puma
           end
 
           o.on "-s", "--silent", "Do not log prompt messages other than errors" do
-            @events = Events.new NullIO.new, $stderr
+            @log_writer = LogWriter.new(NullIO.new, $stderr)
           end
 
           o.on "-S", "--state PATH", "Where to store the state details" do |arg|
diff --git a/lib/puma/cluster.rb b/lib/puma/cluster.rb
index 2862228b..5c5e2c72 100644
--- a/lib/puma/cluster.rb
+++ b/lib/puma/cluster.rb
@@ -17,8 +17,8 @@ module Puma
   # via the `spawn_workers` method call. Each worker will have it's own
   # instance of a `Puma::Server`.
   class Cluster < Runner
-    def initialize(cli, events)
-      super cli, events
+    def initialize(launcher)
+      super(launcher)
 
       @phase = 0
       @workers = []
@@ -96,7 +96,7 @@ module Puma
 
     # @version 5.0.0
     def spawn_worker(idx, master)
-      @launcher.config.run_hooks :before_worker_fork, idx, @launcher.events
+      @launcher.config.run_hooks(:before_worker_fork, idx, @launcher.log_writer)
 
       pid = fork { worker(idx, master) }
       if !pid
@@ -105,7 +105,7 @@ module Puma
         exit! 1
       end
 
-      @launcher.config.run_hooks :after_worker_fork, idx, @launcher.events
+      @launcher.config.run_hooks(:after_worker_fork, idx, @launcher.log_writer)
       pid
     end
 
@@ -413,8 +413,8 @@ module Puma
 
       @master_read, @worker_write = read, @wakeup
 
-      @launcher.config.run_hooks :before_fork, nil, @launcher.events
-      Puma::Util.nakayoshi_gc @events if @options[:nakayoshi_fork]
+      @launcher.config.run_hooks(:before_fork, nil, @launcher.log_writer)
+      Puma::Util.nakayoshi_gc(@log_writer) if @options[:nakayoshi_fork]
 
       spawn_workers
 
diff --git a/lib/puma/cluster/worker.rb b/lib/puma/cluster/worker.rb
index 5cc48898..10e3a9d8 100644
--- a/lib/puma/cluster/worker.rb
+++ b/lib/puma/cluster/worker.rb
@@ -12,7 +12,7 @@ module Puma
       attr_reader :index, :master
 
       def initialize(index:, master:, launcher:, pipes:, server: nil)
-        super launcher, launcher.events
+        super(launcher)
 
         @index = index
         @master = master
@@ -52,7 +52,7 @@ module Puma
 
         # Invoke any worker boot hooks so they can get
         # things in shape before booting the app.
-        @launcher.config.run_hooks :before_worker_boot, index, @launcher.events
+        @launcher.config.run_hooks(:before_worker_boot, index, @launcher.log_writer)
 
         begin
         server = @server ||= start_server
@@ -83,8 +83,8 @@ module Puma
                 if restart_server.length > 0
                   restart_server.clear
                   server.begin_restart(true)
-                  @launcher.config.run_hooks :before_refork, nil, @launcher.events
-                  Puma::Util.nakayoshi_gc @events if @options[:nakayoshi_fork]
+                  @launcher.config.run_hooks(:before_refork, nil, @launcher.log_writer)
+                  Puma::Util.nakayoshi_gc(@log_writer) if @options[:nakayoshi_fork]
                 end
               elsif idx == 0 # restart server
                 restart_server << true << false
@@ -138,7 +138,7 @@ module Puma
 
         # Invoke any worker shutdown hooks so they can prevent the worker
         # exiting until any background operations are completed
-        @launcher.config.run_hooks :before_worker_shutdown, index, @launcher.events
+        @launcher.config.run_hooks(:before_worker_shutdown, index, @launcher.log_writer)
       ensure
         @worker_write << "t#{Process.pid}\n" rescue nil
         @worker_write.close
@@ -147,7 +147,7 @@ module Puma
       private
 
       def spawn_worker(idx)
-        @launcher.config.run_hooks :before_worker_fork, idx, @launcher.events
+        @launcher.config.run_hooks(:before_worker_fork, idx, @launcher.log_writer)
 
         pid = fork do
           new_worker = Worker.new index: idx,
@@ -165,7 +165,7 @@ module Puma
           exit! 1
         end
 
-        @launcher.config.run_hooks :after_worker_fork, idx, @launcher.events
+        @launcher.config.run_hooks(:after_worker_fork, idx, @launcher.log_writer)
         pid
       end
     end
diff --git a/lib/puma/configuration.rb b/lib/puma/configuration.rb
index 9871ff02..5c229c72 100644
--- a/lib/puma/configuration.rb
+++ b/lib/puma/configuration.rb
@@ -291,13 +291,13 @@ module Puma
       @plugins.create name
     end
 
-    def run_hooks(key, arg, events)
+    def run_hooks(key, arg, log_writer)
       @options.all_of(key).each do |b|
         begin
           b.call arg
         rescue => e
-          events.log "WARNING hook #{key} failed with exception (#{e.class}) #{e.message}"
-          events.debug e.backtrace.join("\n")
+          log_writer.log "WARNING hook #{key} failed with exception (#{e.class}) #{e.message}"
+          log_writer.debug e.backtrace.join("\n")
         end
       end
     end
diff --git a/lib/puma/control_cli.rb b/lib/puma/control_cli.rb
index efa3a86e..23030962 100644
--- a/lib/puma/control_cli.rb
+++ b/lib/puma/control_cli.rb
@@ -293,13 +293,13 @@ module Puma
       run_args += ["-C", @config_file] if @config_file
       run_args += ["-e", @environment] if @environment
 
-      events = Puma::Events.new @stdout, @stderr
+      log_writer = Puma::LogWriter.new(@stdout, @stderr)
 
       # replace $0 because puma use it to generate restart command
       puma_cmd = $0.gsub(/pumactl$/, 'puma')
       $0 = puma_cmd if File.exist?(puma_cmd)
 
-      cli = Puma::CLI.new run_args, events
+      cli = Puma::CLI.new run_args, log_writer
       cli.run
     end
   end
diff --git a/lib/puma/events.rb b/lib/puma/events.rb
index f96d5538..3ada3e13 100644
--- a/lib/puma/events.rb
+++ b/lib/puma/events.rb
@@ -1,52 +1,23 @@
 # frozen_string_literal: true
 
-require "puma/null_io"
-require 'puma/error_logger'
-require 'stringio'
-
 module Puma
-  # The default implement of an event sink object used by Server
-  # for when certain kinds of events occur in the life of the server.
-  #
-  # The methods available are the events that the Server fires.
-  #
+
+  # This is an event sink used by `Puma::Server` to handle
+  # lifecycle events such as :on_booted, :on_restart, and :on_stopped.
+  # Using `Puma::DSL` it is possible to register callback hooks
+  # for each event type.
   class Events
-    class DefaultFormatter
-      def call(str)
-        str
-      end
-    end
-
-    class PidFormatter
-      def call(str)
-        "[#{$$}] #{str}"
-      end
-    end
-
-    # Create an Events object that prints to +stdout+ and +stderr+.
-    #
-    def initialize(stdout, stderr)
-      @formatter = DefaultFormatter.new
-      @stdout = stdout
-      @stderr = stderr
-
-      @debug = ENV.key? 'PUMA_DEBUG'
-      @error_logger = ErrorLogger.new(@stderr)
 
+    def initialize
       @hooks = Hash.new { |h,k| h[k] = [] }
     end
 
-    attr_reader :stdout, :stderr
-    attr_accessor :formatter
-
     # Fire callbacks for the named hook
-    #
     def fire(hook, *args)
       @hooks[hook].each { |t| t.call(*args) }
     end
 
     # Register a callback for a given hook
-    #
     def register(hook, obj=nil, &blk)
       if obj and blk
         raise "Specify either an object or a block, not both"
@@ -59,79 +30,6 @@ module Puma
       h
     end
 
-    # Write +str+ to +@stdout+
-    #
-    def log(str)
-      @stdout.puts format(str) if @stdout.respond_to? :puts
-
-      @stdout.flush unless @stdout.sync
-    rescue Errno::EPIPE
-    end
-
-    def write(str)
-      @stdout.write format(str)
-    end
-
-    def debug(str)
-      log("% #{str}") if @debug
-    end
-
-    # Write +str+ to +@stderr+
-    #
-    def error(str)
-      @error_logger.info(text: format("ERROR: #{str}"))
-      exit 1
-    end
-
-    def format(str)
-      formatter.call(str)
-    end
-
-    # An HTTP connection error has occurred.
-    # +error+ a connection exception, +req+ the request,
-    # and +text+ additional info
-    # @version 5.0.0
-    #
-    def connection_error(error, req, text="HTTP connection error")
-      @error_logger.info(error: error, req: req, text: text)
-    end
-
-    # An HTTP parse error has occurred.
-    # +error+ a parsing exception,
-    # and +req+ the request.
-    #
-    def parse_error(error, req)
-      @error_logger.info(error: error, req: req, text: 'HTTP parse error, malformed request')
-    end
-
-    # An SSL error has occurred.
-    # @param error <Puma::MiniSSL::SSLError>
-    # @param ssl_socket <Puma::MiniSSL::Socket>
-    #
-    def ssl_error(error, ssl_socket)
-      peeraddr = ssl_socket.peeraddr.last rescue "<unknown>"
-      peercert = ssl_socket.peercert
-      subject = peercert ? peercert.subject : nil
-      @error_logger.info(error: error, text: "SSL error, peer: #{peeraddr}, peer cert: #{subject}")
-    end
-
-    # An unknown error has occurred.
-    # +error+ an exception object, +req+ the request,
-    # and +text+ additional info
-    #
-    def unknown_error(error, req=nil, text="Unknown error")
-      @error_logger.info(error: error, req: req, text: text)
-    end
-
-    # Log occurred error debug dump.
-    # +error+ an exception object, +req+ the request,
-    # and +text+ additional info
-    # @version 5.0.0
-    #
-    def debug_error(error, req=nil, text="")
-      @error_logger.debug(error: error, req: req, text: text)
-    end
-
     def on_booted(&block)
       register(:on_booted, &block)
     end
@@ -155,23 +53,5 @@ module Puma
     def fire_on_stopped!
       fire(:on_stopped)
     end
-
-    DEFAULT = new(STDOUT, STDERR)
-
-    # Returns an Events object which writes its status to 2 StringIO
-    # objects.
-    #
-    def self.strings
-      Events.new StringIO.new, StringIO.new
-    end
-
-    def self.stdio
-      Events.new $stdout, $stderr
-    end
-
-    def self.null
-      n = NullIO.new
-      Events.new n, n
-    end
   end
 end
diff --git a/lib/puma/launcher.rb b/lib/puma/launcher.rb
index 63202374..d0f8374b 100644
--- a/lib/puma/launcher.rb
+++ b/lib/puma/launcher.rb
@@ -1,5 +1,6 @@
 # frozen_string_literal: true
 
+require 'puma/log_writer'
 require 'puma/events'
 require 'puma/detect'
 require 'puma/cluster'
@@ -27,7 +28,7 @@ module Puma
     # +conf+ A Puma::Configuration object indicating how to run the server.
     #
     # +launcher_args+ A Hash that currently has one required key `:events`,
-    # this is expected to hold an object similar to an `Puma::Events.stdio`,
+    # this is expected to hold an object similar to an `Puma::LogWriter.stdio`,
     # this object will be responsible for broadcasting Puma's internal state
     # to a logging destination. An optional key `:argv` can be supplied,
     # this should be an array of strings, these arguments are re-used when
@@ -41,15 +42,16 @@ module Puma
     #       [200, {}, ["hello world"]]
     #     end
     #   end
-    #   Puma::Launcher.new(conf, events: Puma::Events.stdio).run
+    #   Puma::Launcher.new(conf, log_writer: Puma::LogWriter.stdio).run
     def initialize(conf, launcher_args={})
       @runner        = nil
-      @events        = launcher_args[:events] || Events::DEFAULT
+      @log_writer    = launcher_args[:log_writer] || LogWriter::DEFAULT
+      @events        = launcher_args[:events] || Events.new
       @argv          = launcher_args[:argv] || []
       @original_argv = @argv.dup
       @config        = conf
 
-      @binder        = Binder.new(@events, conf)
+      @binder        = Binder.new(@log_writer, conf)
       @binder.create_inherited_fds(ENV).each { |k| ENV.delete k }
       @binder.create_activated_fds(ENV).each { |k| ENV.delete k }
 
@@ -70,8 +72,8 @@ module Puma
       @options = @config.options
       @config.clamp
 
-      @events.formatter = Events::PidFormatter.new if clustered?
-      @events.formatter = options[:log_formatter] if @options[:log_formatter]
+      @log_writer.formatter = LogWriter::PidFormatter.new if clustered?
+      @log_writer.formatter = options[:log_formatter] if @options[:log_formatter]
 
       generate_restart_data
 
@@ -87,11 +89,11 @@ module Puma
       set_rack_environment
 
       if clustered?
-        @options[:logger] = @events
+        @options[:logger] = @log_writer
 
-        @runner = Cluster.new(self, @events)
+        @runner = Cluster.new(self)
       else
-        @runner = Single.new(self, @events)
+        @runner = Single.new(self)
       end
       Puma.stats_object = @runner
 
@@ -100,7 +102,7 @@ module Puma
       log_config if ENV['PUMA_LOG_CONFIG']
     end
 
-    attr_reader :binder, :events, :config, :options, :restart_dir
+    attr_reader :binder, :log_writer, :events, :config, :options, :restart_dir
 
     # Return stats about the server
     def stats
@@ -263,7 +265,7 @@ module Puma
 
     def restart!
       @events.fire_on_restart!
-      @config.run_hooks :on_restart, self, @events
+      @config.run_hooks :on_restart, self, @log_writer
 
       if Puma.jruby?
         close_binder_listeners
@@ -317,13 +319,13 @@ module Puma
 
       log "* Enabling systemd notification integration"
 
-      systemd = Systemd.new(@events)
+      systemd = Systemd.new(@log_writer, @events)
       systemd.hook_events
       systemd.start_watchdog
     end
 
     def log(str)
-      @events.log str
+      @log_writer.log(str)
     end
 
     def clustered?
@@ -331,7 +333,7 @@ module Puma
     end
 
     def unsupported(str)
-      @events.error(str)
+      @log_writer.error(str)
       raise UnsupportedOption
     end
 
@@ -362,7 +364,7 @@ module Puma
 
     def prune_bundler!
       return unless prune_bundler?
-      BundlePruner.new(@original_argv, @options[:extra_runtime_dependencies], @events).prune
+      BundlePruner.new(@original_argv, @options[:extra_runtime_dependencies], @log_writer).prune
     end
 
     def generate_restart_data
@@ -464,8 +466,8 @@ module Puma
         unless Puma.jruby? # INFO in use by JVM already
           Signal.trap "SIGINFO" do
             thread_status do |name, backtrace|
-              @events.log name
-              @events.log backtrace.map { |bt| "  #{bt}" }
+              @log_writer.log(name)
+              @log_writer.log(backtrace.map { |bt| "  #{bt}" })
             end
           end
         end
diff --git a/lib/puma/launcher/bundle_pruner.rb b/lib/puma/launcher/bundle_pruner.rb
index ef8bade8..a33858e9 100644
--- a/lib/puma/launcher/bundle_pruner.rb
+++ b/lib/puma/launcher/bundle_pruner.rb
@@ -7,10 +7,10 @@ module Puma
     # application restarts.
     class BundlePruner
 
-      def initialize(original_argv, extra_runtime_dependencies, events)
+      def initialize(original_argv, extra_runtime_dependencies, log_writer)
         @original_argv = Array(original_argv)
         @extra_runtime_dependencies = Array(extra_runtime_dependencies)
-        @events = events
+        @log_writer = log_writer
       end
 
       def prune
@@ -96,7 +96,7 @@ module Puma
       end
 
       def log(str)
-        @events.log(str)
+        @log_writer.log(str)
       end
     end
   end
diff --git a/lib/puma/log_writer.rb b/lib/puma/log_writer.rb
new file mode 100644
index 00000000..b765aba3
--- /dev/null
+++ b/lib/puma/log_writer.rb
@@ -0,0 +1,123 @@
+# frozen_string_literal: true
+
+require 'puma/null_io'
+require 'puma/error_logger'
+require 'stringio'
+
+module Puma
+
+  # Handles logging concerns for both standard messages
+  # (+stdout+) and errors (+stderr+).
+  class LogWriter
+
+    class DefaultFormatter
+      def call(str)
+        str
+      end
+    end
+
+    class PidFormatter
+      def call(str)
+        "[#{$$}] #{str}"
+      end
+    end
+
+    attr_reader :stdout,
+                :stderr
+
+    attr_accessor :formatter
+
+    # Create a LogWriter that prints to +stdout+ and +stderr+.
+    def initialize(stdout, stderr)
+      @formatter = DefaultFormatter.new
+      @stdout = stdout
+      @stderr = stderr
+
+      @debug = ENV.key?('PUMA_DEBUG')
+      @error_logger = ErrorLogger.new(@stderr)
+    end
+
+    DEFAULT = new(STDOUT, STDERR)
+
+    # Returns an LogWriter object which writes its status to
+    # two StringIO objects.
+    def self.strings
+      LogWriter.new(StringIO.new, StringIO.new)
+    end
+
+    def self.stdio
+      LogWriter.new($stdout, $stderr)
+    end
+
+    def self.null
+      n = NullIO.new
+      LogWriter.new(n, n)
+    end
+
+    # Write +str+ to +@stdout+
+    def log(str)
+      @stdout.puts(format(str)) if @stdout.respond_to? :puts
+
+      @stdout.flush unless @stdout.sync
+    rescue Errno::EPIPE
+    end
+
+    def write(str)
+      @stdout.write(format(str))
+    end
+
+    def debug(str)
+      log("% #{str}") if @debug
+    end
+
+    # Write +str+ to +@stderr+
+    def error(str)
+      @error_logger.info(text: format("ERROR: #{str}"))
+      exit 1
+    end
+
+    def format(str)
+      formatter.call(str)
+    end
+
+    # An HTTP connection error has occurred.
+    # +error+ a connection exception, +req+ the request,
+    # and +text+ additional info
+    # @version 5.0.0
+    def connection_error(error, req, text="HTTP connection error")
+      @error_logger.info(error: error, req: req, text: text)
+    end
+
+    # An HTTP parse error has occurred.
+    # +error+ a parsing exception,
+    # and +req+ the request.
+    def parse_error(error, req)
+      @error_logger.info(error: error, req: req, text: 'HTTP parse error, malformed request')
+    end
+
+    # An SSL error has occurred.
+    # @param error <Puma::MiniSSL::SSLError>
+    # @param ssl_socket <Puma::MiniSSL::Socket>
+    def ssl_error(error, ssl_socket)
+      peeraddr = ssl_socket.peeraddr.last rescue "<unknown>"
+      peercert = ssl_socket.peercert
+      subject = peercert ? peercert.subject : nil
+      @error_logger.info(error: error, text: "SSL error, peer: #{peeraddr}, peer cert: #{subject}")
+    end
+
+    # An unknown error has occurred.
+    # +error+ an exception object, +req+ the request,
+    # and +text+ additional info
+    def unknown_error(error, req=nil, text="Unknown error")
+      @error_logger.info(error: error, req: req, text: text)
+    end
+
+    # Log occurred error debug dump.
+    # +error+ an exception object, +req+ the request,
+    # and +text+ additional info
+    # @version 5.0.0
+    def debug_error(error, req=nil, text="")
+      @error_logger.debug(error: error, req: req, text: text)
+    end
+  end
+end
diff --git a/lib/puma/minissl/context_builder.rb b/lib/puma/minissl/context_builder.rb
index 8cf16bbd..138d8984 100644
--- a/lib/puma/minissl/context_builder.rb
+++ b/lib/puma/minissl/context_builder.rb
@@ -11,27 +11,27 @@ module Puma
 
         if defined?(JRUBY_VERSION)
           unless params['keystore']
-            events.error "Please specify the Java keystore via 'keystore='"
+            log_writer.error "Please specify the Java keystore via 'keystore='"
           end
 
           ctx.keystore = params['keystore']
 
           unless params['keystore-pass']
-            events.error "Please specify the Java keystore password  via 'keystore-pass='"
+            log_writer.error "Please specify the Java keystore password  via 'keystore-pass='"
           end
 
           ctx.keystore_pass = params['keystore-pass']
           ctx.ssl_cipher_list = params['ssl_cipher_list'] if params['ssl_cipher_list']
         else
           if params['key'].nil? && params['key_pem'].nil?
-            events.error "Please specify the SSL key via 'key=' or 'key_pem='"
+            log_writer.error "Please specify the SSL key via 'key=' or 'key_pem='"
           end
 
           ctx.key = params['key'] if params['key']
           ctx.key_pem = params['key_pem'] if params['key_pem']
 
           if params['cert'].nil? && params['cert_pem'].nil?
-            events.error "Please specify the SSL cert via 'cert=' or 'cert_pem='"
+            log_writer.error "Please specify the SSL cert via 'cert=' or 'cert_pem='"
           end
 
           ctx.cert = params['cert'] if params['cert']
@@ -39,7 +39,7 @@ module Puma
 
           if ['peer', 'force_peer'].include?(params['verify_mode'])
             unless params['ca']
-              events.error "Please specify the SSL ca via 'ca='"
+              log_writer.error "Please specify the SSL ca via 'ca='"
             end
           end
 
@@ -59,7 +59,7 @@ module Puma
                             when "none"
                               MiniSSL::VERIFY_NONE
                             else
-                              events.error "Please specify a valid verify_mode="
+                              log_writer.error "Please specify a valid verify_mode="
                               MiniSSL::VERIFY_NONE
                             end
         end
diff --git a/lib/puma/request.rb b/lib/puma/request.rb
index c9f4c547..10508c8d 100644
--- a/lib/puma/request.rb
+++ b/lib/puma/request.rb
@@ -58,7 +58,7 @@ module Puma
           begin
             fast_write io, str_early_hints(headers)
           rescue ConnectionError => e
-            @events.debug_error e
+            @log_writer.debug_error e
             # noop, if we lost the socket we just won't send the early hints
           end
         }
@@ -89,12 +89,12 @@ module Puma
             return :async
           end
         rescue ThreadPool::ForceShutdown => e
-          @events.unknown_error e, client, "Rack app"
-          @events.log "Detected force shutdown of a thread"
+          @log_writer.unknown_error e, client, "Rack app"
+          @log_writer.log "Detected force shutdown of a thread"
 
           status, headers, res_body = lowlevel_error(e, env, 503)
         rescue Exception => e
-          @events.unknown_error e, client, "Rack app"
+          @log_writer.unknown_error e, client, "Rack app"
 
           status, headers, res_body = lowlevel_error(e, env, 500)
         end
diff --git a/lib/puma/runner.rb b/lib/puma/runner.rb
index e627892c..8553f664 100644
--- a/lib/puma/runner.rb
+++ b/lib/puma/runner.rb
@@ -8,10 +8,11 @@ module Puma
   # serve requests. This class spawns a new instance of `Puma::Server` via
   # a call to `start_server`.
   class Runner
-    def initialize(cli, events)
-      @launcher = cli
-      @events = events
-      @options = cli.options
+    def initialize(launcher)
+      @launcher = launcher
+      @log_writer = launcher.log_writer
+      @events = launcher.events
+      @options = launcher.options
       @app = nil
       @control = nil
       @started_at = Time.now
@@ -40,7 +41,7 @@ module Puma
     end
 
     def log(str)
-      @events.log str
+      @log_writer.log str
     end
 
     # @version 5.0.0
@@ -49,11 +50,11 @@ module Puma
     end
 
     def error(str)
-      @events.error str
+      @log_writer.error str
     end
 
     def debug(str)
-      @events.log "- #{str}" if @options[:debug]
+      @log_writer.log "- #{str}" if @options[:debug]
     end
 
     def start_control
@@ -68,7 +69,7 @@ module Puma
 
       app = Puma::App::Status.new @launcher, token
 
-      control = Puma::Server.new app, @launcher.events,
+      control = Puma::Server.new app, @log_writer, @events,
         { min_threads: 0, max_threads: 1, queue_requests: false }
 
       control.binder.parse [str], self, 'Starting control server'
@@ -166,8 +167,8 @@ module Puma
     end
 
     def start_server
-      server = Puma::Server.new app, @launcher.events, @options
-      server.inherit_binder @launcher.binder
+      server = Puma::Server.new(app, @log_writer, @events, @options)
+      server.inherit_binder(@launcher.binder)
       server
     end
 
diff --git a/lib/puma/server.rb b/lib/puma/server.rb
index f4aed5df..b62f9b97 100644
--- a/lib/puma/server.rb
+++ b/lib/puma/server.rb
@@ -4,6 +4,7 @@ require 'stringio'
 
 require 'puma/thread_pool'
 require 'puma/const'
+require 'puma/log_writer'
 require 'puma/events'
 require 'puma/null_io'
 require 'puma/reactor'
@@ -36,6 +37,7 @@ module Puma
     extend Forwardable
 
     attr_reader :thread
+    attr_reader :log_writer
     attr_reader :events
     attr_reader :min_threads, :max_threads  # for #stats
     attr_reader :requests_count             # @version 5.0.0
@@ -60,8 +62,9 @@ module Puma
 
     # Create a server for the rack app +app+.
     #
-    # +events+ is an object which will be called when certain error events occur
-    # to be handled. See Puma::Events for the list of current methods to implement.
+    # +log_writer+ is a Puma::LogWriter object used to log info and error messages.
+    #
+    # +events+ is a Puma::Events object used to notify application status events.
     #
     # Server#run returns a thread that you can join on to wait for the server
     # to do its work.
@@ -70,8 +73,9 @@ module Puma
     #   and have default values set via +fetch+.  Normally the values are set via
     #   `::Puma::Configuration.puma_default_options`.
     #
-    def initialize(app, events=Events.stdio, options={})
+    def initialize(app, log_writer=LogWriter.stdio, events=Events.new, options={})
       @app = app
+      @log_writer = log_writer
       @events = events
 
       @check, @notify = nil
@@ -97,7 +101,7 @@ module Puma
       temp = !!(@options[:environment] =~ /\A(development|test)\z/)
       @leak_stack_on_error = @options[:environment] ? temp : true
 
-      @binder = Binder.new(events)
+      @binder = Binder.new(log_writer)
 
       ENV['RACK_ENV'] ||= "development"
 
@@ -353,11 +357,11 @@ module Puma
             # In the case that any of the sockets are unexpectedly close.
             raise
           rescue StandardError => e
-            @events.unknown_error e, nil, "Listen loop"
+            @log_writer.unknown_error e, nil, "Listen loop"
           end
         end
 
-        @events.debug "Drained #{drain} additional connections." if drain
+        @log_writer.debug "Drained #{drain} additional connections." if drain
         @events.fire :state, @status
 
         if queue_requests
@@ -366,7 +370,7 @@ module Puma
         end
         graceful_shutdown if @status == :stop || @status == :restart
       rescue Exception => e
-        @events.unknown_error e, nil, "Exception handling servers"
+        @log_writer.unknown_error e, nil, "Exception handling servers"
       ensure
         # RuntimeError is Ruby 2.2 issue, can't modify frozen IOError
         # Errno::EBADF is infrequently raised
@@ -488,7 +492,7 @@ module Puma
           Puma::Util.purge_interrupt_queue
           # Already closed
         rescue StandardError => e
-          @events.unknown_error e, nil, "Client"
+          @log_writer.unknown_error e, nil, "Client"
         end
       end
     end
@@ -511,13 +515,13 @@ module Puma
       lowlevel_error(e, client.env)
       case e
       when MiniSSL::SSLError
-        @events.ssl_error e, client.io
+        @log_writer.ssl_error e, client.io
       when HttpParserError
         client.write_error(400)
-        @events.parse_error e, client
+        @log_writer.parse_error e, client
       else
         client.write_error(500)
-        @events.unknown_error e, nil, "Read"
+        @log_writer.unknown_error e, nil, "Read"
       end
     end
 
diff --git a/lib/puma/systemd.rb b/lib/puma/systemd.rb
index 037e738d..8051b235 100644
--- a/lib/puma/systemd.rb
+++ b/lib/puma/systemd.rb
@@ -4,7 +4,8 @@ require 'sd_notify'
 
 module Puma
   class Systemd
-    def initialize(events)
+    def initialize(log_writer, events)
+      @log_writer = log_writer
       @events = events
     end
 
@@ -40,7 +41,7 @@ module Puma
     end
 
     def log(str)
-      @events.log str
+      @log_writer.log(str)
     end
   end
 end
diff --git a/lib/puma/util.rb b/lib/puma/util.rb
index bf1cabc1..6752735a 100644
--- a/lib/puma/util.rb
+++ b/lib/puma/util.rb
@@ -31,14 +31,14 @@ module Puma
     module_function :unescape
 
     # @version 5.0.0
-    def nakayoshi_gc(events)
-      events.log "! Promoting existing objects to old generation..."
+    def nakayoshi_gc(log_writer)
+      log_writer.log "! Promoting existing objects to old generation..."
       4.times { GC.start(full_mark: false) }
       if GC.respond_to?(:compact)
-        events.log "! Compacting..."
+        log_writer.log "! Compacting..."
         GC.compact
       end
-      events.log "! Friendly fork preparation complete."
+      log_writer.log "! Friendly fork preparation complete."
     end
 
     DEFAULT_SEP = /[&;] */n
diff --git a/lib/rack/handler/puma.rb b/lib/rack/handler/puma.rb
index d00f2306..e06b5677 100644
--- a/lib/rack/handler/puma.rb
+++ b/lib/rack/handler/puma.rb
@@ -13,7 +13,7 @@ module Rack
       def self.config(app, options = {})
         require 'puma'
         require 'puma/configuration'
-        require 'puma/events'
+        require 'puma/log_writer'
         require 'puma/launcher'
 
         default_options = DEFAULT_OPTIONS.dup
@@ -63,9 +63,9 @@ module Rack
       def self.run(app, **options)
         conf   = self.config(app, options)
 
-        events = options.delete(:Silent) ? ::Puma::Events.strings : ::Puma::Events.stdio
+        log_writer = options.delete(:Silent) ? ::Puma::LogWriter.strings : ::Puma::LogWriter.stdio
 
-        launcher = ::Puma::Launcher.new(conf, :events => events)
+        launcher = ::Puma::Launcher.new(conf, :log_writer => log_writer)
 
         yield launcher if block_given?
         begin
diff --git a/test/helper.rb b/test/helper.rb
index f2380625..ae965911 100644
--- a/test/helper.rb
+++ b/test/helper.rb
@@ -33,8 +33,8 @@ require "puma/detect"
 # used in various ssl test files, see test_puma_server_ssl.rb and
 # test_puma_localhost_authority.rb
 if Puma::HAS_SSL
-  require "puma/events"
-  class SSLEventsHelper < ::Puma::Events
+  require 'puma/log_writer'
+  class SSLLogWriterHelper < ::Puma::LogWriter
     attr_accessor :addr, :cert, :error
 
     def ssl_error(error, ssl_socket)
diff --git a/test/test_binder.rb b/test/test_binder.rb
index c2fa42b8..d7bd83b4 100644
--- a/test/test_binder.rb
+++ b/test/test_binder.rb
@@ -13,8 +13,8 @@ class TestBinderBase < Minitest::Test
   include TmpPath
 
   def setup
-    @events = Puma::Events.strings
-    @binder = Puma::Binder.new(@events)
+    @log_writer = Puma::LogWriter.strings
+    @binder = Puma::Binder.new(@log_writer)
   end
 
   def teardown
@@ -80,14 +80,14 @@ class TestBinder < TestBinderBase
   end
 
   def test_localhost_addresses_dont_alter_listeners_for_tcp_addresses
-    @binder.parse ["tcp://localhost:0"], @events
+    @binder.parse ["tcp://localhost:0"], @log_writer
 
     assert_empty @binder.listeners
   end
 
   def test_home_alters_listeners_for_tcp_addresses
     port = UniquePort.call
-    @binder.parse ["tcp://127.0.0.1:#{port}"], @events
+    @binder.parse ["tcp://127.0.0.1:#{port}"], @log_writer
 
     assert_equal "tcp://127.0.0.1:#{port}", @binder.listeners[0][0]
     assert_kind_of TCPServer, @binder.listeners[0][1]
@@ -96,14 +96,14 @@ class TestBinder < TestBinderBase
   def test_connected_ports
     ports = (1..3).map { |_| UniquePort.call }
 
-    @binder.parse(ports.map { |p| "tcp://localhost:#{p}" }, @events)
+    @binder.parse(ports.map { |p| "tcp://localhost:#{p}" }, @log_writer)
 
     assert_equal ports, @binder.connected_ports
   end
 
   def test_localhost_addresses_dont_alter_listeners_for_ssl_addresses
     skip_unless :ssl
-    @binder.parse ["ssl://localhost:0?#{ssl_query}"], @events
+    @binder.parse ["ssl://localhost:0?#{ssl_query}"], @log_writer
 
     assert_empty @binder.listeners
   end
@@ -111,16 +111,16 @@ class TestBinder < TestBinderBase
   def test_home_alters_listeners_for_ssl_addresses
     skip_unless :ssl
     port = UniquePort.call
-    @binder.parse ["ssl://127.0.0.1:#{port}?#{ssl_query}"], @events
+    @binder.parse ["ssl://127.0.0.1:#{port}?#{ssl_query}"], @log_writer
 
     assert_equal "ssl://127.0.0.1:#{port}?#{ssl_query}", @binder.listeners[0][0]
     assert_kind_of TCPServer, @binder.listeners[0][1]
   end
 
   def test_correct_zero_port
-    @binder.parse ["tcp://localhost:0"], @events
+    @binder.parse ["tcp://localhost:0"], @log_writer
 
-    m = %r!http://127.0.0.1:(\d+)!.match(@events.stdout.string)
+    m = %r!http://127.0.0.1:(\d+)!.match(@log_writer.stdout.string)
     port = m[1].to_i
 
     refute_equal 0, port
@@ -131,30 +131,30 @@ class TestBinder < TestBinderBase
 
     ssl_regex = %r!ssl://127.0.0.1:(\d+)!
 
-    @binder.parse ["ssl://localhost:0?#{ssl_query}"], @events
+    @binder.parse ["ssl://localhost:0?#{ssl_query}"], @log_writer
 
-    port = ssl_regex.match(@events.stdout.string)[1].to_i
+    port = ssl_regex.match(@log_writer.stdout.string)[1].to_i
 
     refute_equal 0, port
   end
 
   def test_logs_all_localhost_bindings
-    @binder.parse ["tcp://localhost:0"], @events
+    @binder.parse ["tcp://localhost:0"], @log_writer
 
-    assert_match %r!http://127.0.0.1:(\d+)!, @events.stdout.string
+    assert_match %r!http://127.0.0.1:(\d+)!, @log_writer.stdout.string
     if Socket.ip_address_list.any? {|i| i.ipv6_loopback? }
-      assert_match %r!http://\[::1\]:(\d+)!, @events.stdout.string
+      assert_match %r!http://\[::1\]:(\d+)!, @log_writer.stdout.string
     end
   end
 
   def test_logs_all_localhost_bindings_ssl
     skip_unless :ssl
 
-    @binder.parse ["ssl://localhost:0?#{ssl_query}"], @events
+    @binder.parse ["ssl://localhost:0?#{ssl_query}"], @log_writer
 
-    assert_match %r!ssl://127.0.0.1:(\d+)!, @events.stdout.string
+    assert_match %r!ssl://127.0.0.1:(\d+)!, @log_writer.stdout.string
     if Socket.ip_address_list.any? {|i| i.ipv6_loopback? }
-      assert_match %r!ssl://\[::1\]:(\d+)!, @events.stdout.string
+      assert_match %r!ssl://\[::1\]:(\d+)!, @log_writer.stdout.string
     end
   end
 
@@ -176,9 +176,9 @@ class TestBinder < TestBinderBase
 
     unix_path = tmp_path('.sock')
     File.open(unix_path, mode: 'wb') { |f| f.puts 'pre existing' }
-    @binder.parse ["unix://#{unix_path}"], @events
+    @binder.parse ["unix://#{unix_path}"], @log_writer
 
-    assert_match %r!unix://#{unix_path}!, @events.stdout.string
+    assert_match %r!unix://#{unix_path}!, @log_writer.stdout.string
 
     refute_includes @binder.unix_paths, unix_path
 
@@ -194,7 +194,7 @@ class TestBinder < TestBinderBase
 
   def test_binder_parses_nil_low_latency
     skip_if :jruby
-    @binder.parse ["tcp://0.0.0.0:0?low_latency"], @events
+    @binder.parse ["tcp://0.0.0.0:0?low_latency"], @log_writer
 
     socket = @binder.listeners.first.last
 
@@ -203,7 +203,7 @@ class TestBinder < TestBinderBase
 
   def test_binder_parses_true_low_latency
     skip_if :jruby
-    @binder.parse ["tcp://0.0.0.0:0?low_latency=true"], @events
+    @binder.parse ["tcp://0.0.0.0:0?low_latency=true"], @log_writer
 
     socket = @binder.listeners.first.last
 
@@ -212,7 +212,7 @@ class TestBinder < TestBinderBase
 
   def test_binder_parses_false_low_latency
     skip_if :jruby
-    @binder.parse ["tcp://0.0.0.0:0?low_latency=false"], @events
+    @binder.parse ["tcp://0.0.0.0:0?low_latency=false"], @log_writer
 
     socket = @binder.listeners.first.last
 
@@ -221,21 +221,21 @@ class TestBinder < TestBinderBase
 
   def test_binder_parses_tlsv1_disabled
     skip_unless :ssl
-    @binder.parse ["ssl://0.0.0.0:0?#{ssl_query}&no_tlsv1=true"], @events
+    @binder.parse ["ssl://0.0.0.0:0?#{ssl_query}&no_tlsv1=true"], @log_writer
 
     assert ssl_context_for_binder.no_tlsv1
   end
 
   def test_binder_parses_tlsv1_enabled
     skip_unless :ssl
-    @binder.parse ["ssl://0.0.0.0:0?#{ssl_query}&no_tlsv1=false"], @events
+    @binder.parse ["ssl://0.0.0.0:0?#{ssl_query}&no_tlsv1=false"], @log_writer
 
     refute ssl_context_for_binder.no_tlsv1
   end
 
   def test_binder_parses_tlsv1_tlsv1_1_unspecified_defaults_to_enabled
     skip_unless :ssl
-    @binder.parse ["ssl://0.0.0.0:0?#{ssl_query}"], @events
+    @binder.parse ["ssl://0.0.0.0:0?#{ssl_query}"], @log_writer
 
     refute ssl_context_for_binder.no_tlsv1
     refute ssl_context_for_binder.no_tlsv1_1
@@ -243,21 +243,21 @@ class TestBinder < TestBinderBase
 
   def test_binder_parses_tlsv1_1_disabled
     skip_unless :ssl
-    @binder.parse ["ssl://0.0.0.0:0?#{ssl_query}&no_tlsv1_1=true"], @events
+    @binder.parse ["ssl://0.0.0.0:0?#{ssl_query}&no_tlsv1_1=true"], @log_writer
 
     assert ssl_context_for_binder.no_tlsv1_1
   end
 
   def test_binder_parses_tlsv1_1_enabled
     skip_unless :ssl
-    @binder.parse ["ssl://0.0.0.0:0?#{ssl_query}&no_tlsv1_1=false"], @events
+    @binder.parse ["ssl://0.0.0.0:0?#{ssl_query}&no_tlsv1_1=false"], @log_writer
 
     refute ssl_context_for_binder.no_tlsv1_1
   end
 
   def test_env_contains_protoenv
     skip_unless :ssl
-    @binder.parse ["ssl://localhost:0?#{ssl_query}"], @events
+    @binder.parse ["ssl://localhost:0?#{ssl_query}"], @log_writer
 
     env_hash = @binder.envs[@binder.ios.first]
 
@@ -268,11 +268,11 @@ class TestBinder < TestBinderBase
 
   def test_env_contains_stderr
     skip_unless :ssl
-    @binder.parse ["ssl://localhost:0?#{ssl_query}"], @events
+    @binder.parse ["ssl://localhost:0?#{ssl_query}"], @log_writer
 
     env_hash = @binder.envs[@binder.ios.first]
 
-    assert_equal @events.stderr, env_hash["rack.errors"]
+    assert_equal @log_writer.stderr, env_hash["rack.errors"]
   end
 
   def test_ssl_binder_sets_backlog
@@ -287,7 +287,7 @@ class TestBinder < TestBinderBase
     end
 
     TCPServer.stub(:new, tcp_server) do
-      @binder.parse ["ssl://#{host}:#{port}?#{ssl_query}&backlog=2048"], @events
+      @binder.parse ["ssl://#{host}:#{port}?#{ssl_query}&backlog=2048"], @log_writer
     end
 
     assert_equal 2048, Thread.current[:backlog]
@@ -304,7 +304,7 @@ class TestBinder < TestBinderBase
   end
 
   def test_redirects_for_restart_creates_a_hash
-    @binder.parse ["tcp://127.0.0.1:0"], @events
+    @binder.parse ["tcp://127.0.0.1:0"], @log_writer
 
     result = @binder.redirects_for_restart
     ios = @binder.listeners.map { |_l, io| io.to_i }
@@ -314,7 +314,7 @@ class TestBinder < TestBinderBase
   end
 
   def test_redirects_for_restart_env
-    @binder.parse ["tcp://127.0.0.1:0"], @events
+    @binder.parse ["tcp://127.0.0.1:0"], @log_writer
 
     result = @binder.redirects_for_restart_env
 
@@ -324,7 +324,7 @@ class TestBinder < TestBinderBase
   end
 
   def test_close_listeners_closes_ios
-    @binder.parse ["tcp://127.0.0.1:#{UniquePort.call}"], @events
+    @binder.parse ["tcp://127.0.0.1:#{UniquePort.call}"], @log_writer
 
     refute @binder.listeners.any? { |_l, io| io.closed? }
 
@@ -334,7 +334,7 @@ class TestBinder < TestBinderBase
   end
 
   def test_close_listeners_closes_ios_unless_closed?
-    @binder.parse ["tcp://127.0.0.1:0"], @events
+    @binder.parse ["tcp://127.0.0.1:0"], @log_writer
 
     bomb = @binder.listeners.first[1]
     bomb.close
@@ -351,7 +351,7 @@ class TestBinder < TestBinderBase
     skip_unless :unix
 
     unix_path = tmp_path('.sock')
-    @binder.parse ["unix://#{unix_path}"], @events
+    @binder.parse ["unix://#{unix_path}"], @log_writer
     assert File.socket?(unix_path)
 
     @binder.close_listeners
@@ -359,7 +359,7 @@ class TestBinder < TestBinderBase
   end
 
   def test_import_from_env_listen_inherit
-    @binder.parse ["tcp://127.0.0.1:0"], @events
+    @binder.parse ["tcp://127.0.0.1:0"], @log_writer
     removals = @binder.create_inherited_fds(@binder.redirects_for_restart_env)
 
     @binder.listeners.each do |l, io|
@@ -399,7 +399,7 @@ class TestBinder < TestBinderBase
   end
 
   def test_rack_multithread_default_configuration
-    binder = Puma::Binder.new(@events)
+    binder = Puma::Binder.new(@log_writer)
 
     assert binder.proto_env["rack.multithread"]
   end
@@ -407,13 +407,13 @@ class TestBinder < TestBinderBase
   def test_rack_multithread_custom_configuration
     conf = Puma::Configuration.new(max_threads: 1)
 
-    binder = Puma::Binder.new(@events, conf)
+    binder = Puma::Binder.new(@log_writer, conf)
 
     refute binder.proto_env["rack.multithread"]
   end
 
   def test_rack_multiprocess_default_configuration
-    binder = Puma::Binder.new(@events)
+    binder = Puma::Binder.new(@log_writer)
 
     refute binder.proto_env["rack.multiprocess"]
   end
@@ -421,7 +421,7 @@ class TestBinder < TestBinderBase
   def test_rack_multiprocess_custom_configuration
     conf = Puma::Configuration.new(workers: 1)
 
-    binder = Puma::Binder.new(@events, conf)
+    binder = Puma::Binder.new(@log_writer, conf)
 
     assert binder.proto_env["rack.multiprocess"]
   end
@@ -430,7 +430,7 @@ class TestBinder < TestBinderBase
 
   def assert_activates_sockets(path: nil, port: nil, url: nil, sock: nil)
     hash = { "LISTEN_FDS" => 1, "LISTEN_PID" => $$ }
-    @events.instance_variable_set(:@debug, true)
+    @log_writer.instance_variable_set(:@debug, true)
 
     @binder.instance_variable_set(:@sock_fd, sock.fileno)
     def @binder.socket_activation_fd(int); @sock_fd; end
@@ -440,7 +440,7 @@ class TestBinder < TestBinderBase
     ary = path ? [:unix, path] : [:tcp, url, port]
 
     assert_kind_of TCPServer, @binder.activated_sockets[ary]
-    assert_match "Registered #{ary.join(":")} for activation from LISTEN_FDS", @events.stdout.string
+    assert_match "Registered #{ary.join(":")} for activation from LISTEN_FDS", @log_writer.stdout.string
     assert_equal ["LISTEN_FDS", "LISTEN_PID"], @result
   end
 
@@ -461,8 +461,8 @@ class TestBinder < TestBinderBase
 
     tested_paths = [prepared_paths[order[0]], prepared_paths[order[1]]]
 
-    @binder.parse tested_paths, @events
-    stdout = @events.stdout.string
+    @binder.parse tested_paths, @log_writer
+    stdout = @log_writer.stdout.string
 
     order.each do |prot|
       assert_match expected_logs[prot], stdout
@@ -479,7 +479,7 @@ class TestBinderJRuby < TestBinderBase
     keystore = File.expand_path "../../examples/puma/keystore.jks", __FILE__
     ssl_cipher_list = "TLS_DHE_RSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256"
 
-    @binder.parse ["ssl://0.0.0.0:8080?#{ssl_query}"], @events
+    @binder.parse ["ssl://0.0.0.0:8080?#{ssl_query}"], @log_writer
 
     assert_equal keystore, ssl_context_for_binder.keystore
     assert_equal ssl_cipher_list, ssl_context_for_binder.ssl_cipher_list
@@ -492,7 +492,7 @@ class TestBinderMRI < TestBinderBase
 
     ssl_cipher_filter = "AES@STRENGTH"
 
-    @binder.parse ["ssl://0.0.0.0?#{ssl_query}&ssl_cipher_filter=#{ssl_cipher_filter}"], @events
+    @binder.parse ["ssl://0.0.0.0?#{ssl_query}&ssl_cipher_filter=#{ssl_cipher_filter}"], @log_writer
 
     assert_equal ssl_cipher_filter, ssl_context_for_binder.ssl_cipher_filter
   end
@@ -502,7 +502,7 @@ class TestBinderMRI < TestBinderBase
 
     input = "&verification_flags=TRUSTED_FIRST"
 
-    @binder.parse ["ssl://0.0.0.0?#{ssl_query}#{input}"], @events
+    @binder.parse ["ssl://0.0.0.0?#{ssl_query}#{input}"], @log_writer
 
     assert_equal 0x8000, ssl_context_for_binder.verification_flags
   end
@@ -512,7 +512,7 @@ class TestBinderMRI < TestBinderBase
 
     input = "&verification_flags=TRUSTED_FIRST,NO_CHECK_TIME"
 
-    @binder.parse ["ssl://0.0.0.0?#{ssl_query}#{input}"], @events
+    @binder.parse ["ssl://0.0.0.0?#{ssl_query}#{input}"], @log_writer
 
     assert_equal 0x8000 | 0x200000, ssl_context_for_binder.verification_flags
   end
diff --git a/test/test_bundle_pruner.rb b/test/test_bundle_pruner.rb
index 19d7e651..2ed8eb82 100644
--- a/test/test_bundle_pruner.rb
+++ b/test/test_bundle_pruner.rb
@@ -52,6 +52,6 @@ class TestBundlePruner < Minitest::Test
   private
 
   def bundle_pruner(original_argv = nil, extra_runtime_dependencies = nil)
-    @bundle_pruner ||= Puma::Launcher::BundlePruner.new(original_argv, extra_runtime_dependencies, Puma::Events.null)
+    @bundle_pruner ||= Puma::Launcher::BundlePruner.new(original_argv, extra_runtime_dependencies, Puma::LogWriter.null)
   end
 end
diff --git a/test/test_busy_worker.rb b/test/test_busy_worker.rb
index e5321369..ea46391e 100644
--- a/test/test_busy_worker.rb
+++ b/test/test_busy_worker.rb
@@ -53,7 +53,7 @@ class TestBusyWorker < Minitest::Test
       end
     end
 
-    @server = Puma::Server.new request_handler, Puma::Events.strings, **options
+    @server = Puma::Server.new request_handler, Puma::LogWriter.strings, Puma::Events.new, **options
     @server.min_threads = options[:min_threads] || 0
     @server.max_threads = options[:max_threads] || 10
     @port = (@server.add_tcp_listener '127.0.0.1', 0).addr[1]
diff --git a/test/test_cli.rb b/test/test_cli.rb
index 09670705..ffe32401 100644
--- a/test/test_cli.rb
+++ b/test/test_cli.rb
@@ -21,7 +21,9 @@ class TestCLI < Minitest::Test
 
     @wait, @ready = IO.pipe
 
-    @events = Puma::Events.strings
+    @log_writer = Puma::LogWriter.strings
+
+    @events = Puma::Events.new
     @events.on_booted { @ready << "!" }
   end
 
@@ -47,7 +49,7 @@ class TestCLI < Minitest::Test
     cli = Puma::CLI.new ["-b", "tcp://127.0.0.1:0",
                          "--control-url", url,
                          "--control-token", "",
-                         "test/rackup/lobster.ru"], @events
+                         "test/rackup/lobster.ru"], @log_writer, @events
 
     t = Thread.new do
       cli.run
@@ -82,7 +84,7 @@ class TestCLI < Minitest::Test
     cli = Puma::CLI.new ["-b", "tcp://127.0.0.1:0",
                          "--control-url", control_url,
                          "--control-token", token,
-                         "test/rackup/lobster.ru"], @events
+                         "test/rackup/lobster.ru"], @log_writer, @events
 
     t = Thread.new do
       cli.run
@@ -118,7 +120,7 @@ class TestCLI < Minitest::Test
                          "-w", "2",
                          "--control-url", url,
                          "--control-token", "",
-                         "test/rackup/lobster.ru"], @events
+                         "test/rackup/lobster.ru"], @log_writer, @events
 
     # without this, Minitest.after_run will trigger on this test ?
     $debugging_hold = true
@@ -150,8 +152,8 @@ class TestCLI < Minitest::Test
 
       done = nil
       until done
-        @events.stdout.rewind
-        log = @events.stdout.readlines.join ''
+        @log_writer.stdout.rewind
+        log = @log_writer.stdout.readlines.join ''
         done = log[/ - Goodbye!/]
       end
 
@@ -166,7 +168,7 @@ class TestCLI < Minitest::Test
     cli = Puma::CLI.new ["-b", "unix://#{@tmp_path2}",
                          "--control-url", url,
                          "--control-token", "",
-                         "test/rackup/lobster.ru"], @events
+                         "test/rackup/lobster.ru"], @log_writer, @events
 
     t = Thread.new { cli.run }
 
@@ -193,7 +195,7 @@ class TestCLI < Minitest::Test
     cli = Puma::CLI.new ["-b", "unix://#{@tmp_path2}",
                          "--control-url", url,
                          "--control-token", "",
-                         "test/rackup/lobster.ru"], @events
+                         "test/rackup/lobster.ru"], @log_writer, @events
 
     t = Thread.new { cli.run }
 
@@ -217,7 +219,7 @@ class TestCLI < Minitest::Test
     cli = Puma::CLI.new ["-b", "tcp://127.0.0.1:#{tcp}",
                          "--control-url", url,
                          "--control-token", "",
-                         "test/rackup/lobster.ru"], @events
+                         "test/rackup/lobster.ru"], @log_writer, @events
 
     t = Thread.new do
       cli.run
@@ -258,7 +260,7 @@ class TestCLI < Minitest::Test
     cli = Puma::CLI.new ["-b", "unix://#{@tmp_path2}",
                          "--control-url", url,
                          "--control-token", "",
-                         "test/rackup/lobster.ru"], @events
+                         "test/rackup/lobster.ru"], @log_writer, @events
 
     t = Thread.new { cli.run }
 
@@ -279,7 +281,7 @@ class TestCLI < Minitest::Test
     cli = Puma::CLI.new ["-b", uri,
                          "--control-url", cntl,
                          "--control-token", "",
-                         "test/rackup/lobster.ru"], @events
+                         "test/rackup/lobster.ru"], @log_writer, @events
 
     t = Thread.new do
       cli.run
@@ -384,28 +386,28 @@ class TestCLI < Minitest::Test
 
   def test_log_formatter_default_single
     cli = Puma::CLI.new [ ]
-    assert_instance_of Puma::Events::DefaultFormatter, cli.launcher.events.formatter
+    assert_instance_of Puma::LogWriter::DefaultFormatter, cli.launcher.log_writer.formatter
   end
 
   def test_log_formatter_default_clustered
     skip_unless :fork
 
     cli = Puma::CLI.new [ "-w 2" ]
-    assert_instance_of Puma::Events::PidFormatter, cli.launcher.events.formatter
+    assert_instance_of Puma::LogWriter::PidFormatter, cli.launcher.log_writer.formatter
   end
 
   def test_log_formatter_custom_single
     cli = Puma::CLI.new [ "--config", "test/config/custom_log_formatter.rb" ]
-    assert_instance_of Proc, cli.launcher.events.formatter
-    assert_match(/^\[.*\] \[.*\] .*: test$/, cli.launcher.events.format('test'))
+    assert_instance_of Proc, cli.launcher.log_writer.formatter
+    assert_match(/^\[.*\] \[.*\] .*: test$/, cli.launcher.log_writer.format('test'))
   end
 
   def test_log_formatter_custom_clustered
     skip_unless :fork
 
     cli = Puma::CLI.new [ "--config", "test/config/custom_log_formatter.rb", "-w 2" ]
-    assert_instance_of Proc, cli.launcher.events.formatter
-    assert_match(/^\[.*\] \[.*\] .*: test$/, cli.launcher.events.format('test'))
+    assert_instance_of Proc, cli.launcher.log_writer.formatter
+    assert_match(/^\[.*\] \[.*\] .*: test$/, cli.launcher.log_writer.format('test'))
   end
 
   def test_state
@@ -480,10 +482,10 @@ class TestCLI < Minitest::Test
     cli = Puma::CLI.new ['--silent']
     cli.send(:setup_options)
 
-    events = cli.instance_variable_get(:@events)
+    log_writer = cli.instance_variable_get(:@log_writer)
 
-    assert_equal events.class, Puma::Events.null.class
-    assert_equal events.stdout.class, Puma::NullIO
-    assert_equal events.stderr, $stderr
+    assert_equal log_writer.class, Puma::LogWriter.null.class
+    assert_equal log_writer.stdout.class, Puma::NullIO
+    assert_equal log_writer.stderr, $stderr
   end
 end
diff --git a/test/test_config.rb b/test/test_config.rb
index d2ced63f..16873f0b 100644
--- a/test/test_config.rb
+++ b/test/test_config.rb
@@ -4,7 +4,7 @@ require_relative "helper"
 require_relative "helpers/config_file"
 
 require "puma/configuration"
-require 'puma/events'
+require 'puma/log_writer'
 
 class TestConfigFile < TestConfigFileBase
   parallelize_me!
@@ -373,11 +373,11 @@ class TestConfigFile < TestConfigFileBase
       end
     end
     conf.load
-    events = Puma::Events.strings
+    log_writer = Puma::LogWriter.strings
 
-    conf.run_hooks :on_restart, 'ARG', events
+    conf.run_hooks(:on_restart, 'ARG', log_writer)
     expected = /WARNING hook on_restart failed with exception \(RuntimeError\) Error from hook/
-    assert_match expected, events.stdout.string
+    assert_match expected, log_writer.stdout.string
   end
 
   def test_config_does_not_load_workers_by_default
@@ -419,7 +419,7 @@ class TestConfigFile < TestConfigFileBase
       messages << "#{hook_name} is called with #{a}"
     }
 
-    conf.run_hooks hook_name, 'ARG', Puma::Events.strings
+    conf.run_hooks(hook_name, 'ARG', Puma::LogWriter.strings)
     assert_equal messages, ["#{hook_name} is called with ARG"]
 
     # test multiple
@@ -435,7 +435,7 @@ class TestConfigFile < TestConfigFileBase
     end
     conf.load
 
-    conf.run_hooks hook_name, 'ARG', Puma::Events.strings
+    conf.run_hooks(hook_name, 'ARG', Puma::LogWriter.strings)
     assert_equal messages, ["#{hook_name} is called with ARG one time", "#{hook_name} is called with ARG a second time"]
   end
 end
diff --git a/test/test_events.rb b/test/test_events.rb
index f4df5fb0..4bf8fd83 100644
--- a/test/test_events.rb
+++ b/test/test_events.rb
@@ -2,41 +2,10 @@ require 'puma/events'
 require_relative "helper"
 
 class TestEvents < Minitest::Test
-  def test_null
-    events = Puma::Events.null
-
-    assert_instance_of Puma::NullIO, events.stdout
-    assert_instance_of Puma::NullIO, events.stderr
-    assert_equal events.stdout, events.stderr
-  end
-
-  def test_strings
-    events = Puma::Events.strings
-
-    assert_instance_of StringIO, events.stdout
-    assert_instance_of StringIO, events.stderr
-  end
-
-  def test_stdio
-    events = Puma::Events.stdio
-
-    assert_equal STDOUT, events.stdout
-    assert_equal STDERR, events.stderr
-  end
-
-  def test_stdio_respects_sync
-    events = Puma::Events.stdio
-
-    assert_equal STDOUT.sync, events.stdout.sync
-    assert_equal STDERR.sync, events.stderr.sync
-    assert_equal STDOUT, events.stdout
-    assert_equal STDERR, events.stderr
-  end
-
   def test_register_callback_with_block
     res = false
 
-    events = Puma::Events.null
+    events = Puma::Events.new
 
     events.register(:exec) { res = true }
 
@@ -56,7 +25,7 @@ class TestEvents < Minitest::Test
       @res = true
     end
 
-    events = Puma::Events.null
+    events = Puma::Events.new
 
     events.register(:exec, obj)
 
@@ -68,7 +37,7 @@ class TestEvents < Minitest::Test
   def test_fire_callback_with_multiple_arguments
     res = []
 
-    events = Puma::Events.null
+    events = Puma::Events.new
 
     events.register(:exec) { |*args| res.concat(args) }
 
@@ -80,7 +49,7 @@ class TestEvents < Minitest::Test
   def test_on_booted_callback
     res = false
 
-    events = Puma::Events.null
+    events = Puma::Events.new
 
     events.on_booted { res = true }
 
@@ -88,151 +57,4 @@ class TestEvents < Minitest::Test
 
     assert res
   end
-
-  def test_log_writes_to_stdout
-    out, _ = capture_io do
-      Puma::Events.stdio.log("ready")
-    end
-
-    assert_equal "ready\n", out
-  end
-
-  def test_null_log_does_nothing
-    out, _ = capture_io do
-      Puma::Events.null.log("ready")
-    end
-
-    assert_equal "", out
-  end
-
-  def test_write_writes_to_stdout
-    out, _ = capture_io do
-      Puma::Events.stdio.write("ready")
-    end
-
-    assert_equal "ready", out
-  end
-
-  def test_debug_writes_to_stdout_if_env_is_present
-    original_debug, ENV["PUMA_DEBUG"] = ENV["PUMA_DEBUG"], "1"
-
-    out, _ = capture_io do
-      Puma::Events.stdio.debug("ready")
-    end
-
-    assert_equal "% ready\n", out
-  ensure
-    ENV["PUMA_DEBUG"] = original_debug
-  end
-
-  def test_debug_not_write_to_stdout_if_env_is_not_present
-    out, _ = capture_io do
-      Puma::Events.stdio.debug("ready")
-    end
-
-    assert_empty out
-  end
-
-  def test_error_writes_to_stderr_and_exits
-    did_exit = false
-
-    _, err = capture_io do
-      begin
-        Puma::Events.stdio.error("interrupted")
-      rescue SystemExit
-        did_exit = true
-      ensure
-        assert did_exit
-      end
-    end
-
-    assert_match %r!ERROR: interrupted!, err
-  end
-
-  def test_pid_formatter
-    pid = Process.pid
-
-    out, _ = capture_io do
-      events = Puma::Events.stdio
-
-      events.formatter = Puma::Events::PidFormatter.new
-
-      events.write("ready")
-    end
-
-    assert_equal "[#{ pid }] ready", out
-  end
-
-  def test_custom_log_formatter
-    custom_formatter = proc { |str| "-> #{ str }" }
-
-    out, _ = capture_io do
-      events = Puma::Events.stdio
-
-      events.formatter = custom_formatter
-
-      events.write("ready")
-    end
-
-    assert_equal "-> ready", out
-  end
-
-  def test_parse_error
-    port = 0
-    host = "127.0.0.1"
-    app = proc { |env| [200, {"Content-Type" => "plain/text"}, ["hello\n"]] }
-    events = Puma::Events.strings
-    server = Puma::Server.new app, events
-
-    port = (server.add_tcp_listener host, 0).addr[1]
-    server.run
-
-    sock = TCPSocket.new host, port
-    path = "/"
-    params = "a"*1024*10
-
-    sock << "GET #{path}?a=#{params} HTTP/1.1\r\nConnection: close\r\n\r\n"
-    sock.read
-    sleep 0.1 # important so that the previous data is sent as a packet
-    assert_match %r!HTTP parse error, malformed request!, events.stderr.string
-    assert_match %r!\("GET #{path}" - \(-\)\)!, events.stderr.string
-  ensure
-    sock.close if sock && !sock.closed?
-    server.stop true
-  end
-
-  # test_puma_server_ssl.rb checks that ssl errors are raised correctly,
-  # but it mocks the actual error code.  This test the code, but it will
-  # break if the logged message changes
-  def test_ssl_error
-    events = Puma::Events.strings
-
-    ssl_mock = -> (addr, subj) {
-      obj = Object.new
-      obj.define_singleton_method(:peeraddr) { addr }
-      if subj
-        cert = Object.new
-        cert.define_singleton_method(:subject) { subj }
-        obj.define_singleton_method(:peercert) { cert }
-      else
-        obj.define_singleton_method(:peercert) { nil }
-      end
-      obj
-    }
-
-    events.ssl_error OpenSSL::SSL::SSLError, ssl_mock.call(['127.0.0.1'], 'test_cert')
-    error = events.stderr.string
-    assert_includes error, "SSL error"
-    assert_includes error, "peer: 127.0.0.1"
-    assert_includes error, "cert: test_cert"
-
-    events.stderr.string = ''
-
-    events.ssl_error OpenSSL::SSL::SSLError, ssl_mock.call(nil, nil)
-    error = events.stderr.string
-    assert_includes error, "SSL error"
-    assert_includes error, "peer: <unknown>"
-    assert_includes error, "cert: :"
-
-  end if ::Puma::HAS_SSL
 end
diff --git a/test/test_launcher.rb b/test/test_launcher.rb
index 30abe6b7..573dedd1 100644
--- a/test/test_launcher.rb
+++ b/test/test_launcher.rb
@@ -2,7 +2,7 @@ require_relative "helper"
 require_relative "helpers/tmp_path"
 
 require "puma/configuration"
-require 'puma/events'
+require 'puma/log_writer'
 
 class TestLauncher < Minitest::Test
   include TmpPath
@@ -112,17 +112,17 @@ class TestLauncher < Minitest::Test
   def test_log_config_enabled
     ENV['PUMA_LOG_CONFIG'] = "1"
 
-    assert_match(/Configuration:/, launcher.events.stdout.string)
+    assert_match(/Configuration:/, launcher.log_writer.stdout.string)
 
     launcher.config.final_options.each do |config_key, _value|
-      assert_match(/#{config_key}/, launcher.events.stdout.string)
+      assert_match(/#{config_key}/, launcher.log_writer.stdout.string)
     end
 
     ENV.delete('PUMA_LOG_CONFIG')
   end
 
   def test_log_config_disabled
-    refute_match(/Configuration:/, launcher.events.stdout.string)
+    refute_match(/Configuration:/, launcher.log_writer.stdout.string)
   end
 
   def test_fire_on_stopped
@@ -147,11 +147,11 @@ class TestLauncher < Minitest::Test
 
   private
 
-  def events
-    @events ||= Puma::Events.strings
+  def log_writer
+    @log_writer ||= Puma::LogWriter.strings
   end
 
-  def launcher(config = Puma::Configuration.new, evts = events)
-    @launcher ||= Puma::Launcher.new(config, events: evts)
+  def launcher(config = Puma::Configuration.new, lw = log_writer)
+    @launcher ||= Puma::Launcher.new(config, log_writer: lw)
   end
 end
diff --git a/test/test_log_writer.rb b/test/test_log_writer.rb
new file mode 100644
index 00000000..0b9502b8
--- /dev/null
+++ b/test/test_log_writer.rb
@@ -0,0 +1,181 @@
+require 'puma/log_writer'
+require_relative "helper"
+
+class TestLogWriter < Minitest::Test
+  def test_null
+    log_writer = Puma::LogWriter.null
+
+    assert_instance_of Puma::NullIO, log_writer.stdout
+    assert_instance_of Puma::NullIO, log_writer.stderr
+    assert_equal log_writer.stdout, log_writer.stderr
+  end
+
+  def test_strings
+    log_writer = Puma::LogWriter.strings
+
+    assert_instance_of StringIO, log_writer.stdout
+    assert_instance_of StringIO, log_writer.stderr
+  end
+
+  def test_stdio
+    log_writer = Puma::LogWriter.stdio
+
+    assert_equal STDOUT, log_writer.stdout
+    assert_equal STDERR, log_writer.stderr
+  end
+
+  def test_stdio_respects_sync
+    log_writer = Puma::LogWriter.stdio
+
+    assert_equal STDOUT.sync, log_writer.stdout.sync
+    assert_equal STDERR.sync, log_writer.stderr.sync
+    assert_equal STDOUT, log_writer.stdout
+    assert_equal STDERR, log_writer.stderr
+  end
+
+  def test_log_writes_to_stdout
+    out, _ = capture_io do
+      Puma::LogWriter.stdio.log("ready")
+    end
+
+    assert_equal "ready\n", out
+  end
+
+  def test_null_log_does_nothing
+    out, _ = capture_io do
+      Puma::LogWriter.null.log("ready")
+    end
+
+    assert_equal "", out
+  end
+
+  def test_write_writes_to_stdout
+    out, _ = capture_io do
+      Puma::LogWriter.stdio.write("ready")
+    end
+
+    assert_equal "ready", out
+  end
+
+  def test_debug_writes_to_stdout_if_env_is_present
+    original_debug, ENV["PUMA_DEBUG"] = ENV["PUMA_DEBUG"], "1"
+
+    out, _ = capture_io do
+      Puma::LogWriter.stdio.debug("ready")
+    end
+
+    assert_equal "% ready\n", out
+  ensure
+    ENV["PUMA_DEBUG"] = original_debug
+  end
+
+  def test_debug_not_write_to_stdout_if_env_is_not_present
+    out, _ = capture_io do
+      Puma::LogWriter.stdio.debug("ready")
+    end
+
+    assert_empty out
+  end
+
+  def test_error_writes_to_stderr_and_exits
+    did_exit = false
+
+    _, err = capture_io do
+      begin
+        Puma::LogWriter.stdio.error("interrupted")
+      rescue SystemExit
+        did_exit = true
+      ensure
+        assert did_exit
+      end
+    end
+
+    assert_match %r!ERROR: interrupted!, err
+  end
+
+  def test_pid_formatter
+    pid = Process.pid
+
+    out, _ = capture_io do
+      log_writer = Puma::LogWriter.stdio
+
+      log_writer.formatter = Puma::LogWriter::PidFormatter.new
+
+      log_writer.write("ready")
+    end
+
+    assert_equal "[#{ pid }] ready", out
+  end
+
+  def test_custom_log_formatter
+    custom_formatter = proc { |str| "-> #{ str }" }
+
+    out, _ = capture_io do
+      log_writer = Puma::LogWriter.stdio
+
+      log_writer.formatter = custom_formatter
+
+      log_writer.write("ready")
+    end
+
+    assert_equal "-> ready", out
+  end
+
+  def test_parse_error
+    app = proc { |_env| [200, {"Content-Type" => "plain/text"}, ["hello\n"]] }
+    log_writer = Puma::LogWriter.strings
+    server = Puma::Server.new app, log_writer
+
+    host = '127.0.0.1'
+    port = (server.add_tcp_listener host, 0).addr[1]
+    server.run
+
+    sock = TCPSocket.new host, port
+    path = "/"
+    params = "a"*1024*10
+
+    sock << "GET #{path}?a=#{params} HTTP/1.1\r\nConnection: close\r\n\r\n"
+    sock.read
+    sleep 0.1 # important so that the previous data is sent as a packet
+    assert_match %r!HTTP parse error, malformed request!, log_writer.stderr.string
+    assert_match %r!\("GET #{path}" - \(-\)\)!, log_writer.stderr.string
+  ensure
+    sock.close if sock && !sock.closed?
+    server.stop true
+  end
+
+  # test_puma_server_ssl.rb checks that ssl errors are raised correctly,
+  # but it mocks the actual error code.  This test the code, but it will
+  # break if the logged message changes
+  def test_ssl_error
+    log_writer = Puma::LogWriter.strings
+
+    ssl_mock = -> (addr, subj) {
+      obj = Object.new
+      obj.define_singleton_method(:peeraddr) { addr }
+      if subj
+        cert = Object.new
+        cert.define_singleton_method(:subject) { subj }
+        obj.define_singleton_method(:peercert) { cert }
+      else
+        obj.define_singleton_method(:peercert) { nil }
+      end
+      obj
+    }
+
+    log_writer.ssl_error OpenSSL::SSL::SSLError, ssl_mock.call(['127.0.0.1'], 'test_cert')
+    error = log_writer.stderr.string
+    assert_includes error, "SSL error"
+    assert_includes error, "peer: 127.0.0.1"
+    assert_includes error, "cert: test_cert"
+
+    log_writer.stderr.string = ''
+
+    log_writer.ssl_error OpenSSL::SSL::SSLError, ssl_mock.call(nil, nil)
+    error = log_writer.stderr.string
+    assert_includes error, "SSL error"
+    assert_includes error, "peer: <unknown>"
+    assert_includes error, "cert: :"
+
+  end if ::Puma::HAS_SSL
+end
diff --git a/test/test_out_of_band_server.rb b/test/test_out_of_band_server.rb
index 27eec9b7..c0ca7d4a 100644
--- a/test/test_out_of_band_server.rb
+++ b/test/test_out_of_band_server.rb
@@ -59,7 +59,7 @@ class TestOutOfBandServer < Minitest::Test
       [200, {}, [""]]
     end
 
-    @server = Puma::Server.new app, Puma::Events.strings, out_of_band: [oob], **options
+    @server = Puma::Server.new app, Puma::LogWriter.strings, Puma::Events.new, out_of_band: [oob], **options
     @server.min_threads = options[:min_threads] || 1
     @server.max_threads = options[:max_threads] || 1
     @port = (@server.add_tcp_listener '127.0.0.1', 0).addr[1]
diff --git a/test/test_puma_localhost_authority.rb b/test/test_puma_localhost_authority.rb
index 8599980b..f40c4ec1 100644
--- a/test/test_puma_localhost_authority.rb
+++ b/test/test_puma_localhost_authority.rb
@@ -30,8 +30,8 @@ class TestPumaLocalhostAuthority < Minitest::Test
     @host = "localhost"
     app = lambda { |env| [200, {}, [env['rack.url_scheme']]] }
 
-    @events = SSLEventsHelper.new STDOUT, STDERR
-    @server = Puma::Server.new app, @events
+    @log_writer = SSLLogWriterHelper.new STDOUT, STDERR
+    @server = Puma::Server.new app, @log_writer
     @server.app = app
     @server.add_ssl_listener @host, 0,nil
     @http = Net::HTTP.new @host, @server.connected_ports[0]
@@ -61,9 +61,9 @@ class TestPumaSSLLocalhostAuthority < Minitest::Test
 
     app = lambda { |env| [200, {}, [env['rack.url_scheme']]] }
 
-    @events = SSLEventsHelper.new STDOUT, STDERR
+    @log_writer = SSLLogWriterHelper.new STDOUT, STDERR
 
-    @server = Puma::Server.new app, @events
+    @server = Puma::Server.new app, @log_writer
     @server.app = app
 
     @server.add_ssl_listener @host, 0,nil
diff --git a/test/test_puma_server.rb b/test/test_puma_server.rb
index 4909f268..f89490ec 100644
--- a/test/test_puma_server.rb
+++ b/test/test_puma_server.rb
@@ -14,8 +14,9 @@ class TestPumaServer < Minitest::Test
 
     @app = ->(env) { [200, {}, [env['rack.url_scheme']]] }
 
-    @events = Puma::Events.strings
-    @server = Puma::Server.new @app, @events
+    @log_writer = Puma::LogWriter.strings
+    @events = Puma::Events.new
+    @server = Puma::Server.new @app, @log_writer, @events
   end
 
   def teardown
@@ -24,7 +25,7 @@ class TestPumaServer < Minitest::Test
   end
 
   def server_run(**options, &block)
-    @server = Puma::Server.new block || @app, @events, options
+    @server = Puma::Server.new block || @app, @log_writer, @events, options
     @port = (@server.add_tcp_listener @host, 0).addr[1]
     @server.run
     sleep 0.15 if Puma.jruby?
@@ -296,7 +297,7 @@ EOF
     sleep 0.1
 
     # Expect no errors in stderr
-    assert @events.stderr.pos.zero?, "Server didn't swallow the connection error"
+    assert @log_writer.stderr.pos.zero?, "Server didn't swallow the connection error"
   end
 
   def test_early_hints_is_off_by_default
@@ -341,7 +342,7 @@ EOF
     new_connection.close # Make a connection and close without writing
 
     @server.stop(true)
-    stderr = @events.stderr.string
+    stderr = @log_writer.stderr.string
     assert stderr.empty?, "Expected stderr from server to be empty but it was #{stderr.inspect}"
   end
 
@@ -361,7 +362,7 @@ EOF
 
   def test_lowlevel_error_message
     skip_if :windows
-    @server = Puma::Server.new @app, @events, {:force_shutdown_after => 2}
+    @server = Puma::Server.new @app, @log_writer, @events, {:force_shutdown_after => 2}
 
     server_run do
       if TestSkips::TRUFFLE
@@ -508,7 +509,7 @@ EOF
   end
 
   def test_no_timeout_after_data_received_no_queue
-    @server = Puma::Server.new @app, @events, queue_requests: false
+    @server = Puma::Server.new @app, @log_writer, @events, queue_requests: false
     test_no_timeout_after_data_received
   end
 
@@ -1244,7 +1245,7 @@ EOF
   # System-resource errors such as EMFILE should not be silently swallowed by accept loop.
   def test_accept_emfile
     stub_accept_nonblock Errno::EMFILE.new('accept(2)')
-    refute_empty @events.stderr.string, "Expected EMFILE error not logged"
+    refute_empty @log_writer.stderr.string, "Expected EMFILE error not logged"
   end
 
   # Retryable errors such as ECONNABORTED should be silently swallowed by accept loop.
@@ -1252,7 +1253,7 @@ EOF
     # Match Ruby #accept_nonblock implementation, ECONNABORTED error is extended by IO::WaitReadable.
     error = Errno::ECONNABORTED.new('accept(2) would block').tap {|e| e.extend IO::WaitReadable}
     stub_accept_nonblock(error)
-    assert_empty @events.stderr.string
+    assert_empty @log_writer.stderr.string
   end
 
   # see      https://github.com/puma/puma/issues/2390
@@ -1260,7 +1261,7 @@ EOF
   #
   def test_client_quick_close_no_lowlevel_error_handler_call
     handler = ->(err, env, status) {
-      @events.stdout.write "LLEH #{err.message}"
+      @log_writer.stdout.write "LLEH #{err.message}"
       [500, {"Content-Type" => "application/json"}, ["{}\n"]]
     }
 
@@ -1274,21 +1275,21 @@ EOF
     sock.close
     assert_match 'Hello World', resp
     sleep 0.5
-    assert_empty @events.stdout.string
+    assert_empty @log_writer.stdout.string
 
     # valid req, close
     sock = TCPSocket.new @host, @port
     sock.syswrite "GET / HTTP/1.0\r\n\r\n"
     sock.close
     sleep 0.5
-    assert_empty @events.stdout.string
+    assert_empty @log_writer.stdout.string
 
     # invalid req, close
     sock = TCPSocket.new @host, @port
     sock.syswrite "GET / HTTP"
     sock.close
     sleep 0.5
-    assert_empty @events.stdout.string
+    assert_empty @log_writer.stdout.string
   end
 
   def test_idle_connections_closed_immediately_on_shutdown
@@ -1325,7 +1326,7 @@ EOF
   def test_custom_io_selector
     backend = NIO::Selector.backends.first
 
-    @server = Puma::Server.new @app, @events, {:io_selector_backend => backend}
+    @server = Puma::Server.new @app, @log_writer, @events, {:io_selector_backend => backend}
     @server.run
 
     selector = @server.instance_variable_get(:@reactor).instance_variable_get(:@selector)
@@ -1374,9 +1375,9 @@ EOF
     @port = UniquePort.call
     opts = { rack_url_scheme: 'user', binds: ["tcp://#{@host}:#{@port}"] }
     conf = Puma::Configuration.new(opts).tap(&:clamp)
-    @server = Puma::Server.new @app, @events, conf.options
-    @server.inherit_binder Puma::Binder.new(@events, conf)
-    @server.binder.parse conf.options[:binds], @events
+    @server = Puma::Server.new @app, @log_writer, @events, conf.options
+    @server.inherit_binder Puma::Binder.new(@log_writer, conf)
+    @server.binder.parse conf.options[:binds], @log_writer
     @server.run
 
     data = send_http_and_read "GET / HTTP/1.0\r\n\r\n"
diff --git a/test/test_puma_server_ssl.rb b/test/test_puma_server_ssl.rb
index 58fd6507..4d08d0ec 100644
--- a/test/test_puma_server_ssl.rb
+++ b/test/test_puma_server_ssl.rb
@@ -55,8 +55,8 @@ class TestPumaServerSSL < Minitest::Test
 
     yield ctx if block_given?
 
-    @events = SSLEventsHelper.new STDOUT, STDERR
-    @server = Puma::Server.new app, @events
+    @log_writer = SSLLogWriterHelper.new STDOUT, STDERR
+    @server = Puma::Server.new app, @log_writer
     @port = (@server.add_ssl_listener @host, 0, ctx).addr[1]
     @server.run
 
@@ -148,7 +148,7 @@ class TestPumaServerSSL < Minitest::Test
     end
     unless Puma.jruby?
       msg = /wrong version number|no protocols available|version too low|unknown SSL method/
-      assert_match(msg, @events.error.message) if @events.error
+      assert_match(msg, @log_writer.error.message) if @log_writer.error
     end
   end
 
@@ -169,7 +169,7 @@ class TestPumaServerSSL < Minitest::Test
     end
     unless Puma.jruby?
       msg = /wrong version number|(unknown|unsupported) protocol|no protocols available|version too low|unknown SSL method/
-      assert_match(msg, @events.error.message) if @events.error
+      assert_match(msg, @log_writer.error.message) if @log_writer.error
     end
   end
 
@@ -189,7 +189,7 @@ class TestPumaServerSSL < Minitest::Test
     end
     unless Puma.jruby?
       msg = /wrong version number|(unknown|unsupported) protocol|no protocols available|version too low|unknown SSL method/
-      assert_match(msg, @events.error.message) if @events.error
+      assert_match(msg, @log_writer.error.message) if @log_writer.error
     end
   end
 
@@ -258,8 +258,8 @@ class TestPumaServerSSLClient < Minitest::Test
 
     app = lambda { |env| [200, {}, [env['rack.url_scheme']]] }
 
-    events = SSLEventsHelper.new STDOUT, STDERR
-    server = Puma::Server.new app, events
+    log_writer = SSLLogWriterHelper.new STDOUT, STDERR
+    server = Puma::Server.new app, log_writer
     server.add_ssl_listener host, port, CTX
     host_addrs = server.binder.ios.map { |io| io.to_io.addr[2] }
     server.run
@@ -288,9 +288,9 @@ class TestPumaServerSSLClient < Minitest::Test
     # The JRuby MiniSSL implementation lacks error capturing currently,
     # so we can't inspect the messages here
     unless Puma.jruby?
-      assert_match error, events.error.message if error
-      assert_includes host_addrs, events.addr if error
-      assert_equal subject, events.cert.subject.to_s if subject
+      assert_match error, log_writer.error.message if error
+      assert_includes host_addrs, log_writer.addr if error
+      assert_equal subject, log_writer.cert.subject.to_s if subject
     end
   ensure
     server.stop(true) if server
@@ -346,8 +346,8 @@ class TestPumaServerSSLWithCertPemAndKeyPem < Minitest::Test
     }
 
     app = lambda { |env| [200, {}, [env['rack.url_scheme']]] }
-    events = SSLEventsHelper.new STDOUT, STDERR
-    server = Puma::Server.new app, events
+    log_writer = SSLLogWriterHelper.new STDOUT, STDERR
+    server = Puma::Server.new app, log_writer
     server.add_ssl_listener host, port, ctx
     server.run
 
diff --git a/test/test_response_header.rb b/test/test_response_header.rb
index 508bbcd7..4c1edfd8 100644
--- a/test/test_response_header.rb
+++ b/test/test_response_header.rb
@@ -12,8 +12,8 @@ class TestResponseHeader < Minitest::Test
 
     @app = ->(env) { [200, {}, [env['rack.url_scheme']]] }
 
-    @events = Puma::Events.strings
-    @server = Puma::Server.new @app, @events
+    @log_writer = Puma::LogWriter.strings
+    @server = Puma::Server.new @app, @log_writer
   end
 
   def teardown
diff --git a/test/test_web_server.rb b/test/test_web_server.rb
index 9dc1093c..dea8117f 100644
--- a/test/test_web_server.rb
+++ b/test/test_web_server.rb
@@ -23,7 +23,7 @@ class WebServerTest < Minitest::Test
 
   def setup
     @tester = TestHandler.new
-    @server = Puma::Server.new @tester, Puma::Events.strings
+    @server = Puma::Server.new @tester, Puma::LogWriter.strings
     @port = (@server.add_tcp_listener "127.0.0.1", 0).addr[1]
     @tcp = "http://127.0.0.1:#{@port}"
     @server.run