fix(infra): change iris spec for stability in parellel grading (#2253)

* fix(infra): allocate 1.7GB memory to IRIS container for stability in parallel grading

* fix(infra): configure 2 ec2 instances, each running a signle Iris container

* fix(infra): reduce ECS scale-up detection period to 30 seconds for faster response

apps/infra/production/codedang/codedang_iris.tf

@@ -12,7 +12,7 @@ module "codedang_iris" {
   autoscaling_group = {
     name             = "Codedang-AutoScalingGroup-Iris"
     max_size         = 4
-    desired_capacity = 1
+    desired_capacity = 2
   }
 
   autoscaling_policy = {

apps/infra/production/codedang/codedang_service_iris.tf

@@ -31,7 +31,7 @@ module "iris" {
   task_definition = {
     family = "Codedang-Iris-Api"
     cpu    = 512
-    memory = 512
+    memory = 1700
 
     container_definitions = jsonencode([
       jsondecode(templatefile("container_definitions/iris.json", {

apps/infra/production/codedang/modules/service_autoscaling/appautoscaling_scale_up.tf

@@ -8,7 +8,7 @@ resource "aws_cloudwatch_metric_alarm" "scale_up" {
   evaluation_periods  = 1
   metric_name         = "CPUUtilization"
   namespace           = "AWS/ECS"
-  period              = 60
+  period              = 30
   statistic           = var.scale_up.cloudwatch_metric_alarm.statistic
   threshold           = var.scale_up.cloudwatch_metric_alarm.threshold