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Fix cloudwatch alarm failure to create (#56) #77

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Merged
merged 2 commits into from
Aug 25, 2020
Merged

Fix cloudwatch alarm failure to create (#56) #77

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a0ea3ba
Fix cloudwatch alarm fail (#56)
varunpalekar Aug 14, 2020
9aa4730
Update replica group count mechanism to pre-calculate count before ap…
varunpalekar Aug 19, 2020
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21 changes: 15 additions & 6 deletions main.tf
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Original file line number Diff line number Diff line change
Expand Up @@ -54,6 +54,15 @@ resource "aws_security_group_rule" "ingress_cidr_blocks" {

locals {
elasticache_subnet_group_name = var.elasticache_subnet_group_name != "" ? var.elasticache_subnet_group_name : join("", aws_elasticache_subnet_group.default.*.name)
# if !cluster, then node_count = replica cluster_size, if cluster then node_count = shard*(replica + 1)
# Why doing this 'The "count" value depends on resource attributes that cannot be determined until apply'. So pre-calculating
member_clusters_count = (var.cluster_mode_enabled
?
(var.cluster_mode_num_node_groups * (var.cluster_mode_replicas_per_node_group + 1))
:
var.cluster_size
)
elasticache_member_clusters = var.enabled ? tolist(aws_elasticache_replication_group.default.0.member_clusters) : []
}

resource "aws_elasticache_subnet_group" "default" {
Expand Down Expand Up @@ -117,8 +126,8 @@ resource "aws_elasticache_replication_group" "default" {
# CloudWatch Resources
#
resource "aws_cloudwatch_metric_alarm" "cache_cpu" {
count = var.enabled ? 1 : 0
alarm_name = "${module.label.id}-cpu-utilization"
count = var.enabled ? local.member_clusters_count : 0
alarm_name = "${element(local.elasticache_member_clusters, count.index)}-cpu-utilization"
alarm_description = "Redis cluster CPU utilization"
comparison_operator = "GreaterThanThreshold"
evaluation_periods = "1"
Expand All @@ -130,7 +139,7 @@ resource "aws_cloudwatch_metric_alarm" "cache_cpu" {
threshold = var.alarm_cpu_threshold_percent

dimensions = {
CacheClusterId = module.label.id
CacheClusterId = element(local.elasticache_member_clusters, count.index)
}

alarm_actions = var.alarm_actions
Expand All @@ -139,8 +148,8 @@ resource "aws_cloudwatch_metric_alarm" "cache_cpu" {
}

resource "aws_cloudwatch_metric_alarm" "cache_memory" {
count = var.enabled ? 1 : 0
alarm_name = "${module.label.id}-freeable-memory"
count = var.enabled ? local.member_clusters_count : 0
alarm_name = "${element(local.elasticache_member_clusters, count.index)}-freeable-memory"
alarm_description = "Redis cluster freeable memory"
comparison_operator = "LessThanThreshold"
evaluation_periods = "1"
Expand All @@ -152,7 +161,7 @@ resource "aws_cloudwatch_metric_alarm" "cache_memory" {
threshold = var.alarm_memory_threshold_bytes

dimensions = {
CacheClusterId = module.label.id
CacheClusterId = element(local.elasticache_member_clusters, count.index)
}

alarm_actions = var.alarm_actions
Expand Down