Added lp1366997-workaround config option. It is disabled by default.

Enabling it will add two config options in my.cnf, as described
in lp1366997.

templates/my.cnf

@@ -33,14 +33,13 @@ innodb_locks_unsafe_for_binlog=1
 # This changes how InnoDB autoincrement locks are managed and is a requirement for Galera
 innodb_autoinc_lock_mode=2
 
+{% if innodb_file_per_table -%}
 # This enables storing InnoDB tables in separate .ibd files. Note that, however
-# existing InnoDB tables will remain in ibdata file(s) unles OPTIMIZE is run 
+# existing InnoDB tables will remain in ibdata file(s) unles OPTIMIZE is run
 # on them. Still, the ibdata1 file will NOT shrink - a full dump/import of the
 # data is needed in order to get rid of large ibdata file.
-
-{% if innodb_file_per_table %} 
 innodb_file_per_table = 1
-{% else %}
+{% else -%}
 innodb_file_per_table = 0
 {% endif %}
 
@@ -69,10 +68,17 @@ max_allowed_packet = 16M
 # query cache is not supported with Active/Active configuration
 innodb_buffer_pool_size = {{ dataset_bytes }}
 
-{% if ipv6 %}
+{% if ipv6 -%}
 [sst]
 sockopt=,pf=ip6
 {% endif %}
 
+{% if lp1366997_workaround -%}
+# Adding workaround for bug:
+#    https://bugs.launchpad.net/charms/+source/percona-cluster/+bug/1366997
+# Note that this should only be required for percona 5.5
+wsrep_drupal_282555_workaround = ON
+wsrep_retry_autocommit = 100
+{% endif %}
 
 !includedir /etc/mysql/conf.d/