Cloudwatch

A. Cloudwatch : Metric

• namespace-1 :
• metric-1 : attribute/dimension-1, ... upto attribute-30. eg; instanceId,EnvName,etc
• metric-2 : attribute/dimension-1, ...
• ...
• metric are variable for monitoring
• metric resolution : how offer metric get run/refresh
• default : 5 min.
• standard : 1 min
• high : 1/5/10/30 sec
  • A CloudWatch Alarm set on a High-Resolution Custom Metric, can be triggered as often as every 10 seconds.
  • high-resolution alarm with a period of 10 seconds or 30 seconds
  • or you can set a regular alarm with a period of any multiple of 60 seconds

1. Inbuilt metric

• metric enabled by default.
• can disable them.
• eg - for ec2:
• cpu utilization
• network call
• ...
• NOTE: ASG uses these metric for auto-scaling.
  • change metric resolution to standard/high for better response

2. Custom metric

• can Define and Send custom metric on EC2 or any other service (eg- cw:log-group,etc)
• eg:
• EC2::RAM/memory utilization
• EC2::disk utilization
• ??::number of logged User
• ...
• ...
• CW-log::metric-filter-1
  • search pattern1 in log and create metric around it.

• Step-1 : Define/create

  # create log-metric-filter on log-group-1
  
  log-group-1 > metric-filter tab
      - name: filter-1
      - namespace: filter-namespace-1
      - filter pattern : "error"
      - metric value : 100
      - so, when error found in metric will occur with value 100
  

• Step-2 : send : PutMetricData API

  aws cloudwatch put-metric-data \
      --namespace <namespace-1> \
      --metric-name <metric_name> \
      --value <value> \
      [--dimensions <name=value,...>] \
      [--unit <unit>] \
      [--timestamp <timestamp>]
  

  aws cloudwatch put-metric-data \
      --namespace MyApp/Performance \
      --metric-data file://metrics.json
  
  # metrics.json    
  [
    {
      "MetricName": "CPUUsage",
      "Value": 75.5,
      "Unit": "Percent",
      "Dimensions": [
        { "Name": "InstanceId", "Value": "i-12345678" }
      ]
    },
    {
      "MetricName": "DiskUsage",
      "Value": 60.0,
      "Unit": "Percent"
    }
  ]
  

3 dashboard

CW::dashboard

• check on AWS console
• check by region for ec2 or other service
• check by namespace
• 

external::dashboard

• create custom metric
• deliver the stream of metric data, using KDF to:
• 3rd party : datadog, splunk, dynatrace
• then use 3rd party dashboard

---

extra

CLI

• PutMetricData : push custom metric data, eg: RAM

metric collected by CW unified agent

• installed on on-prem/Ec2.
• metric (just for idea, not for exam)
• CPU (active, guest, idle, system, user, steal)
• Disk metrics (free, used, total), Disk IO (writes, reads, bytes, iops)
• RAM (free, inactive, used, total, cached)
• Netstat (number of TCP and UDP connections, net packets, bytes)
• Processes (total, dead, bloqued, idle, running, sleep)

Aggregate metric from ASG's ec2 instance.

• install unified agen in all EC2 inatance in ASG
• agent config: use "aggregation_dimension" , to aggregate metric from all instance.