From 49a4be72777616f0b721c3779cf29f146311240d Mon Sep 17 00:00:00 2001
From: Christian Schwede <cschwede@redhat.com>
Date: Mon, 31 Oct 2016 23:01:23 +0100
Subject: [PATCH] Add nonblocking_notify to Swift proxy ceilometer config

This allows to send Ceilometer notifications in a background thread, no
longer blocking Swift proxy if the RabbitMQ is not available.

This patch does not change the default behavior.

Change-Id: Iad1f69f273fe80176c6010f8f3cc24313d7c5ab4
---
 manifests/proxy/ceilometer.pp                          |  6 ++++++
 ...blocking-ceilometermiddleware-3ed113824614016c.yaml | 10 ++++++++++
 spec/classes/swift_proxy_ceilometer_spec.rb            |  4 ++++
 3 files changed, 20 insertions(+)
 create mode 100644 releasenotes/notes/non-blocking-ceilometermiddleware-3ed113824614016c.yaml

diff --git a/manifests/proxy/ceilometer.pp b/manifests/proxy/ceilometer.pp
index 4e254fe5..2b8f0472 100644
--- a/manifests/proxy/ceilometer.pp
+++ b/manifests/proxy/ceilometer.pp
@@ -54,6 +54,10 @@
 #   ceilometer/wsgi: set $::apache::group
 #   Defaults to 'ceilometer'
 #
+# [*nonblocking_notify*]
+#   Whether to send events to messaging driver in a background thread
+#   Defaults to false
+#
 # == Examples
 #
 # == Authors
@@ -76,6 +80,7 @@ class swift::proxy::ceilometer(
   $control_exchange    = undef,
   $ensure              = 'present',
   $group               = 'ceilometer',
+  $nonblocking_notify  = false,
 ) inherits swift {
 
   include ::swift::deps
@@ -113,6 +118,7 @@ class swift::proxy::ceilometer(
     'filter:ceilometer/url':                  value => $url;
     'filter:ceilometer/control_exchange':     value => $control_exchange;
     'filter:ceilometer/paste.filter_factory': value => 'ceilometermiddleware.swift:filter_factory';
+    'filter:ceilometer/nonblocking_notify':   value => $nonblocking_notify;
   }
 
   package { 'python-ceilometermiddleware':
diff --git a/releasenotes/notes/non-blocking-ceilometermiddleware-3ed113824614016c.yaml b/releasenotes/notes/non-blocking-ceilometermiddleware-3ed113824614016c.yaml
new file mode 100644
index 00000000..0cc46675
--- /dev/null
+++ b/releasenotes/notes/non-blocking-ceilometermiddleware-3ed113824614016c.yaml
@@ -0,0 +1,10 @@
+---
+features:
+  - A new ceilometermiddleware option "nonblocking_notify" has been
+    added and can be used to send notifications in a separate background
+    thread. This avoids blocking of Swift if RabbitMQ is not able to
+    process new notifications. In this case notifications will be
+    dropped after the local queue (defaults to 1000 entries) is
+    exhausted. It requires the Newton release of ceilometermiddleware.
+    This option is disabled by default and not changing the current
+    behavior.
diff --git a/spec/classes/swift_proxy_ceilometer_spec.rb b/spec/classes/swift_proxy_ceilometer_spec.rb
index 5e1edfe8..76c182ab 100644
--- a/spec/classes/swift_proxy_ceilometer_spec.rb
+++ b/spec/classes/swift_proxy_ceilometer_spec.rb
@@ -16,6 +16,7 @@ describe 'swift::proxy::ceilometer' do
   describe "when using default parameters" do
     it { is_expected.to contain_swift_proxy_config('filter:ceilometer/paste.filter_factory').with_value('ceilometermiddleware.swift:filter_factory') }
     it { is_expected.to contain_swift_proxy_config('filter:ceilometer/url').with_value('rabbit://guest:guest@127.0.0.1:5672//') }
+    it { is_expected.to contain_swift_proxy_config('filter:ceilometer/nonblocking_notify').with_value('false') }
     it { is_expected.to contain_user('swift').with_groups('ceilometer') }
     it { is_expected.to contain_file('/var/log/ceilometer/swift-proxy-server.log').with(:owner => 'swift', :group => 'swift', :mode => '0664') }
   end
@@ -31,6 +32,7 @@ describe 'swift::proxy::ceilometer' do
         :driver              => 'messagingv2',
         :topic               => 'notifications',
         :control_exchange    => 'swift',
+        :nonblocking_notify  => true,
       }
     end
 
@@ -41,6 +43,7 @@ describe 'swift::proxy::ceilometer' do
       it { is_expected.to contain_swift_proxy_config('filter:ceilometer/driver').with_value('messagingv2') }
       it { is_expected.to contain_swift_proxy_config('filter:ceilometer/topic').with_value('notifications') }
       it { is_expected.to contain_swift_proxy_config('filter:ceilometer/control_exchange').with_value('swift') }
+      it { is_expected.to contain_swift_proxy_config('filter:ceilometer/nonblocking_notify').with_value('true') }
     end
 
     context 'with multiple rabbit hosts' do
@@ -54,6 +57,7 @@ describe 'swift::proxy::ceilometer' do
       it { is_expected.to contain_swift_proxy_config('filter:ceilometer/driver').with_value('messagingv2') }
       it { is_expected.to contain_swift_proxy_config('filter:ceilometer/topic').with_value('notifications') }
       it { is_expected.to contain_swift_proxy_config('filter:ceilometer/control_exchange').with_value('swift') }
+      it { is_expected.to contain_swift_proxy_config('filter:ceilometer/nonblocking_notify').with_value('true') }
     end
 
   end