Increase maximum payload size for Monasca Log API

Increase the maximum payload size so that it slightly exceeds the default
maximum chunk size (8MB) in Fluentd. This prevents the Monasca Log API
dropping logs when under heavy load.

Partially-Implements: blueprint monasca-roles
Change-Id: I13020abde7de1c92acc07352466b814b4a6ce5bc

ansible/roles/monasca/templates/monasca-log-api/log-api.conf.j2

@@ -5,6 +5,8 @@ debug = {{ monasca_logging_debug }}
 
 [service]
 region = {{ openstack_region_name }}
+# Increase the maximum payload size to slightly above the default Fluentd chunk size (8MB)
+max_log_size = 10485760
 
 [kafka_healthcheck]
 kafka_topics = {{ monasca_raw_logs_topic }}