config: add support for --listen-backlog flag

Signed-off-by: Jakub Sokołowski <jakub@status.im>

defaults/main.yml

@@ -8,6 +8,7 @@ memcached_size_mb: 64
 memcached_max_item_size: '1m'
 memcached_maxconn: 1024
 memcached_max_reqs_per_event: 20
+memcached_listen_backlog: 1024
 
 memcached_verbose: 'false'
 memcached_log_file: '/var/log/memcached.log'

templates/memcached.conf.j2

@@ -50,6 +50,9 @@ logfile {{ memcached_log_file }}
 starvation (default: 20)
 -R {{ memcached_max_reqs_per_event }}
 
+# Set the backlog queue limit (default: 1024)
+-b {{ memcached_listen_backlog }}
+
 # Lock down all paged memory. Consult with the README and homepage before you do this
 # -k