Add HashClient retry options for the dogpile.cache backend

This patch specifies a set of options required to setup the HashClient
retry feature of dogpile.cache cache backend.

Original oslo.cache change:
https://review.opendev.org/c/openstack/oslo.cache/+/824944

Depends-On: https://review.opendev.org/826870
Change-Id: Idb2fe7e5573103d9e7ef36652fc2b4252418cdc3

manifests/init.pp

@@ -208,6 +208,22 @@
 #   (Optional) Number of seconds to sleep between each attempt.
 #   Default to $::os_service_default
 #
+# [*cache_hashclient_retry_attempts*]
+#   (Optional) Amount of times a client should be tried
+#   before it is marked dead and removed from the pool in
+#   the HashClient's internal mechanisms.
+#   Default to $::os_service_default
+#
+# [*cache_hashclient_retry_delay*]
+#   (Optional) Time in seconds that should pass between
+#   retry attempts in the HashClient's internal mechanisms.
+#   Default to $::os_service_default
+#
+# [*cache_dead_timeout*]
+#   (Optional) Time in seconds before attempting to add a node
+#   back in the pool in the HashClient's internal mechanisms.
+#   Default to $::os_service_default
+#
 # [*manage_backend_package*]
 #   (Optional) If we should install the cache backend package.
 #   Defaults to true
@@ -344,6 +360,9 @@ class ceilometer(
   $cache_enable_retry_client          = $::os_service_default,
   $cache_retry_attempts               = $::os_service_default,
   $cache_retry_delay                  = $::os_service_default,
+  $cache_hashclient_retry_attempts    = $::os_service_default,
+  $cache_hashclient_retry_delay       = $::os_service_default,
+  $cache_dead_timeout                 = $::os_service_default,
   $manage_backend_package             = true,
   $amqp_server_request_prefix         = $::os_service_default,
   $amqp_broadcast_prefix              = $::os_service_default,
@@ -477,6 +496,9 @@ will be removed in a future release.')
     enable_retry_client       => $cache_enable_retry_client,
     retry_attempts            => $cache_retry_attempts,
     retry_delay               => $cache_retry_delay,
+    hashclient_retry_attempts => $cache_hashclient_retry_attempts,
+    hashclient_retry_delay    => $cache_hashclient_retry_delay,
+    dead_timeout              => $cache_dead_timeout,
     manage_backend_package    => $manage_backend_package,
   }
 }

releasenotes/notes/add_cache_hashclient_retry_options-474e86180db9699f.yaml

@@ -0,0 +1,5 @@
+---
+features:
+  - |
+    Add options to configure pymemcache's HashClient retrying mechanisms
+    (dogpile.cache) backend.

spec/classes/ceilometer_init_spec.rb

@@ -139,6 +139,9 @@ describe 'ceilometer' do
         :enable_retry_client       => '<SERVICE DEFAULT>',
         :retry_attempts            => '<SERVICE DEFAULT>',
         :retry_delay               => '<SERVICE DEFAULT>',
+        :hashclient_retry_attempts => '<SERVICE DEFAULT>',
+        :hashclient_retry_delay    => '<SERVICE DEFAULT>',
+        :dead_timeout              => '<SERVICE DEFAULT>',
         :manage_backend_package    => true,
       )
     end
@@ -181,6 +184,9 @@ describe 'ceilometer' do
           :cache_enable_retry_client       => false,
           :cache_retry_attempts            => 2,
           :cache_retry_delay               => 0,
+          :cache_hashclient_retry_attempts => 2,
+          :cache_hashclient_retry_delay    => 1,
+          :cache_dead_timeout              => 60,
           :manage_backend_package          => false,
         )
       }
@@ -197,6 +203,9 @@ describe 'ceilometer' do
           :enable_retry_client       => false,
           :retry_attempts            => 2,
           :retry_delay               => 0,
+          :hashclient_retry_attempts => 2,
+          :hashclient_retry_delay    => 1,
+          :dead_timeout              => 60,
           :manage_backend_package    => false,
         )
       end