Add the ability to set the JVM heap size

This change makes it possible for users to set the `elastic_heap_size_default`
value. Before this change, the option was unreachable due to a series of facts
ganerated template values. The options `elastic_heap_size` or `logstash_heap_size`
have also been exposed giving deployers the ability to define service specific
heap sizes as needed.

Change-Id: Ida3a57fdcff388f8e4bb3f325b787205a6183970
Signed-off-by: Kevin Carter <kevin@cloudnull.com>

elk_metrics_6x/roles/elastic_dependencies/defaults/main.yml

@@ -42,3 +42,8 @@ elastic_lxc_template_config:
   2:
     aa_profile: lxc.aa_profile
     mount: lxc.mount.entry
+
+# Set the elastic search heap size. If this option is undefined the value will
+# be derived automatically using 1/4 of the available RAM for logstash and 1/2
+# of the available RAM for elasticsearch. The value is expected to be in MiB.
+# elastic_heap_size_default: 10240  # type `int`

elk_metrics_6x/roles/elastic_dependencies/tasks/main.yml

@@ -49,9 +49,8 @@
   tags:
     - always
 
-- name: Set elastic heap defaults
+- name: Set elastic log rotate path
   set_fact:
-    elastic_heap_size_default: "{{ _elastic_heap_size_default }}"
     elastic_log_rotate_path: "/var/log/{{ service_name }}"
 
 - name: Configure systcl vm.max_map_count=524288 on elastic hosts

elk_metrics_6x/roles/elastic_logstash/defaults/main.yml

@@ -86,3 +86,8 @@ logstash_arcsight_event_brokers: []
 ## detect the media type where the queue will exist. If the media type is
 ## "rotational" in memory queues will be used.
 # logstash_queue_type:
+
+# Set the logstash search heap size. If this option is undefined the value will
+# be derived automatically using 1/4 of the available RAM for logstash and 1/2
+# of the available RAM for elasticsearch. The value is expected to be in MiB.
+# logstash_heap_size: 10240  # type `int`

elk_metrics_6x/roles/elastic_logstash/tasks/main.yml

@@ -71,6 +71,12 @@
     - key: LS_OPEN_FILES
       value: 32768
 
+- name: Set service specific haap size
+  set_fact:
+    _service_heap_size: "{{ logstash_heap_size }}"
+  when:
+    - logstash_heap_size is defined
+
 - name: Drop jvm conf file(s)
   template:
     src: "{{ item.src }}"

elk_metrics_6x/roles/elasticsearch/defaults/main.yml

@@ -28,3 +28,8 @@ elastic_plugins:
   - ingest-attachment
   - ingest-geoip
   - ingest-user-agent
+
+# Set the logstash search heap size. If this option is undefined the value will
+# be derived automatically using 1/4 of the available RAM for logstash and 1/2
+# of the available RAM for elasticsearch. The value is expected to be in MiB.
+# elastic_heap_size: 10240  # type `int`

elk_metrics_6x/roles/elasticsearch/tasks/main.yml

@@ -81,6 +81,12 @@
     - key: MAX_MAP_COUNT
       value: 524288
 
+- name: Set service specific haap size
+  set_fact:
+    _service_heap_size: "{{ elastic_heap_size }}"
+  when:
+    - elastic_heap_size is defined
+
 - name: Drop jvm conf file(s)
   template:
     src: "{{ item.src }}"

elk_metrics_6x/roles/elasticsearch/vars/vars_default.yml

@@ -13,5 +13,4 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# Set elasticsearch facts
-elastic_heap_size: "{{ elastic_heap_size_default }}"
+place_holder: true

elk_metrics_6x/roles/elasticsearch/vars/vars_kibana.yml

@@ -18,7 +18,6 @@ elasticsearch_node_master: false
 elasticsearch_node_data: false
 elasticsearch_node_ingest: false
 elastic_coordination_node: true
-elastic_heap_size: "{{ (elastic_heap_size_default | int) // 3 }}"
 
 # This variable is redefined because kibana runs elasticsearch but only in a
 # load balancer capacity.

elk_metrics_6x/templates/jvm.options.j2

@@ -1,8 +1,12 @@
 ## JVM configuration
-{% if (not (elasticsearch_node_master | default(master_node)) | bool) and (not (elasticsearch_node_data | default(data_node)) | bool) %}
-{%   set heap_size = (elastic_heap_size_default | int) // 2 %}
+{% if _service_heap_size is defined %}
+{%   set heap_size = _service_heap_size %}
 {% else %}
-{%   set heap_size = (elastic_heap_size_default | int) %}
+{%   if (not (elasticsearch_node_master | default(master_node)) | bool) and (not (elasticsearch_node_data | default(data_node)) | bool) %}
+{%     set heap_size = elastic_heap_size_default | default((_elastic_heap_size_default | int) // 2) %}
+{%   else %}
+{%     set heap_size = elastic_heap_size_default | default(_elastic_heap_size_default | int) %}
+{%   endif %}
 {% endif %}
 # Xms represents the initial size of total heap space
 -Xms{{ heap_size }}m