20474: Changes RailsAPI queue size to be 10% more than controller's.

Also, adds comment on config file clarifying why we're setting up this
increased value.

Arvados-DCO-1.1-Signed-off-by: Lucas Di Pentima <lucas.dipentima@curii.com>

diff --git a/tools/salt-install/config_examples/multi_host/aws/pillars/nginx_passenger.sls b/tools/salt-install/config_examples/multi_host/aws/pillars/nginx_passenger.sls
index bd1aacffac09db43041ed884115c4932e0064576..7bbf9ae618a3c065e78af5ecfaad8d126c98eb62 100644 (file)
--- a/tools/salt-install/config_examples/multi_host/aws/pillars/nginx_passenger.sls
+++ b/tools/salt-install/config_examples/multi_host/aws/pillars/nginx_passenger.sls
@@ -24,8 +24,9 @@ nginx:
     passenger_max_pool_size: {{ "__CONTROLLER_NGINX_WORKERS__" or grains['num_cpus'] }}
     {%- set max_reqs = "__CONTROLLER_MAX_CONCURRENT_REQUESTS__" %}
     {%- if max_reqs != "" and max_reqs is number %}
-    # Default is 100
-    passenger_max_request_queue_size: {{ max_reqs + 5 }}
+    # Default is 100 -- Configuring this a bit higher than API.MaxConcurrentRequests
+    # to be able to handle /metrics requests even on heavy load situations.
+    passenger_max_request_queue_size: {{ (max_reqs * 1.1)|round|int }}
     {%- endif %}
 
   ### SERVER