Add setting to override max memcached connections

Added MemcachedMaxConnections to allow max connection override as
actually the limit is 8192 connections but in some cases the environment
will create more than 8192 connections to each memcached server.

Closes-Bug: #1911664

NB:
Conflicts: deployment/memcached/memcached-container-puppet.yaml

Change-Id: Iaef7c01127327f709577bef3d2e96db840ba2b80
(cherry picked from commit bbed1ef)
(cherry picked from commit 751b03c7878c264b449894f8d4ff238d66a2e8a6)

deployment/memcached/memcached-container-puppet.yaml

@@ -42,6 +42,10 @@ parameters:
                  to use when installed. This can be either a percentage ('50%')
                  or a fixed value ('2048').
     type: string
+  MemcachedMaxConnections:
+    default: 8192
+    description: The maximum number of connections to be accepted by memcached
+    type: number
   MonitoringSubscriptionMemcached:
     default: 'overcloud-memcached'
     type: string
@@ -125,6 +129,7 @@ outputs:
               "%{hiera('$NETWORK_uri')}"
             params:
               $NETWORK: {get_param: [ServiceNetMap, MemcachedNetwork]}
+        memcached::max_connections: {get_param: MemcachedMaxConnections}
         memcached::max_memory: {get_param: MemcachedMaxMemory}
         # https://access.redhat.com/security/cve/cve-2018-1000115
         # Only accept TCP to avoid spoofed traffic amplification DoS on UDP.

releasenotes/notes/addmemcachedmaxconnections-b591c0fa39e821f5.yaml

@@ -0,0 +1,6 @@
+---
+features:
+  - |
+    Added ``MemcachedMaxConnections`` setting with a default of 8192 maximum
+    connections in order to allow an operator to override that value in
+    environments where memcached is heavily sollicited.