configurator: per-listener backlog, {rcv,snd}buf config

Instead of having global options for all listeners,
make all socket options per-listener.  This allows
reverse-proxies to pick different listeners to get
different options on different sockets.

  Given a cluster of machines (10.0.0.1, 10.0.0.2, 10.0.0.3)
  running Unicorn with the following config:

  ------------------ 8< ----------------
  listen "/tmp/local.sock", :backlog => 1
  listen "*:8080" # use the backlog=1024 default
  ------------------ 8< ----------------

  It is possible to configure a reverse proxy to try to use
  "/tmp/local.sock" first and then fall back to using the
  TCP listener on port 8080 in a failover configuration.

  Thus the nginx upstream configuration on 10.0.0.1 to
  compliment this would be:
  ------------------ 8< ----------------
  upstream unicorn_cluster {
    # reject connections ASAP if we are overloaded
    server unix:/tmp/local.sock;

    # fall back to other machines in the cluster via "backup"
    # listeners which have a large backlog queue.
    server 10.0.0.2:8080 backup;
    server 10.0.0.3:8080 backup;
  }
  ------------------ 8< ----------------

This removes the global "backlog" config option which
was inflexible with multiple machines in a cluster
and exposes the ability to change SO_SNDBUF/SO_RCVBUF
via setsockopt(2) for the first time.

2 files changed, 24 insertions, 1 deletions

diff --git a/test/exec/test_exec.rb b/test/exec/test_exec.rb
index caada3b..5f91dc5 100644
--- a/test/exec/test_exec.rb
+++ b/test/exec/test_exec.rb
@@ -47,7 +47,6 @@ end
   HEAVY_CFG = <<-EOS
 worker_processes 4
 timeout 30
-backlog 128
 logger Logger.new('#{COMMON_TMP.path}')
 before_fork do |server, worker_nr|
   server.logger.info "before_fork: worker=\#{worker_nr}"
diff --git a/test/unit/test_configurator.rb b/test/unit/test_configurator.rb
index 8de0b13..623d717 100644
--- a/test/unit/test_configurator.rb
+++ b/test/unit/test_configurator.rb
@@ -45,4 +45,28 @@ class TestConfigurator < Test::Unit::TestCase
     assert_nil @logger
   end
 
+  def test_listen_options
+    tmp = Tempfile.new('unicorn_config')
+    expect = { :sndbuf => 1, :rcvbuf => 2, :backlog => 10 }.freeze
+    listener = "127.0.0.1:12345"
+    tmp.syswrite("listen '#{listener}', #{expect.inspect}\n")
+    cfg = nil
+    assert_nothing_raised do
+      cfg = Unicorn::Configurator.new(:config_file => tmp.path)
+    end
+    assert_nothing_raised { cfg.commit!(self) }
+    assert(listener_opts = instance_variable_get("@listener_opts"))
+    assert_equal expect, listener_opts[listener]
+  end
+
+  def test_listen_option_bad
+    tmp = Tempfile.new('unicorn_config')
+    expect = { :sndbuf => "five" }
+    listener = "127.0.0.1:12345"
+    tmp.syswrite("listen '#{listener}', #{expect.inspect}\n")
+    assert_raises(ArgumentError) do
+      Unicorn::Configurator.new(:config_file => tmp.path)
+    end
+  end
+
 end