Specify how frequently dashboard checks for data update

New config parameter 'dashboard-update-interval' is introduced.
The interval specifies how frequently dashboard should check
for updates in seconds. Default value is 1 hour (3600 seconds).

This allows to avoid situation when dashboard needs to update data
(rebuild indexes, purge cache) on every request that happens when
processor runs.

Closes bug 1324653

Change-Id: Ie86568eb5ec758e4f93bc3583f7bcce0f19df72f

dashboard/vault.py

@@ -68,8 +68,13 @@ def get_vault():
             LOG.exception(e)
             flask.abort(500)
 
-    if not getattr(flask.request, 'stackalytics_updated', None):
+    time_now = utils.date_to_timestamp('now')
+    may_update_by_time = (time_now > vault.get('vault_update_time', 0) +
+                          cfg.CONF.dashboard_update_interval)
+    if (may_update_by_time and
+            not getattr(flask.request, 'stackalytics_updated', None)):
         flask.request.stackalytics_updated = True
+        vault['vault_update_time'] = time_now
         memory_storage_inst = vault['memory_storage']
         have_updates = memory_storage_inst.update(
             compact_records(vault['runtime_storage'].get_update(os.getpid())))

etc/stackalytics.conf

@@ -46,3 +46,6 @@
 
 # Default project type
 # default_project_type = openstack
+
+# The interval specifies how frequently dashboard should check for updates in seconds
+# dashboard-update-interval = 3600

stackalytics/processor/config.py

@@ -53,4 +53,7 @@ OPTS = [
                help='Default release, the most recent if not set'),
     cfg.StrOpt('default-project-type', default='openstack',
                help='Default project type'),
+    cfg.IntOpt('dashboard-update-interval', default=3600,
+               help='The interval specifies how frequently dashboard should '
+                    'check for updates in seconds'),
 ]