What are Metrics
- They can be customized to suit our needs
- e.g. memory utilization
- Metric filters: Define which metrics to extract and pub to cloudWatch
What’s a “namespace”?
- Used to isolate diff apps and metrics
- Naming convention for namespaces:
- EBS - AWS/EBS
- ELB - AWS/ELB
- EC2 - AWS/EC2
Key elements for filtering metrics?
- Filter pattern
- Metric name
- Metric value
- e.g. counting 404 errors = value of 1 for each error
What are logs?
- Log events: The activity being reported
- Log streams: A source of log events from the same source
- Log group: Log events with the same properties, policies, access controls
- E.g. logfiles on ec2 from log agent
Are cloudWatch logs automatically encrypted at rest?
What about log group data? Encrypted?
Does CloudWatch Logs manage server-side encryption keys?
What if you need to manage the encryption keys manually?
- Use “customer master keys” in KMS
What’s the “Log Agent”?
- Agent we can install on ec2 to auto-pub log events to cloudWatch
- Can be on beanstalk, CF, OpsWorks ec2 instances
- Installed via AWS API, CLI, or SDK’s (e.g. boto3)
- Monitors a log file, sends it out
Do cloudwatch metrics go cross-region?
How long before CloudWatch metrics expire?
- 15 months, if no new data is published to a metric
What are cloudWatch “periods”?
- Control what’s aggregated in stats
- Can be used for alarms
What are CloudWatch “dimensions”?
- Name/value pair uniquely identifying a metric
- ec2 InstanceId
- ec2 InstanceType
- ec2 AutoScalingGroupName
- ELB AvailabilityZone
- ELB loadBalancerName
Diff between metrics and logs?
- E.g. in a load balancer:
- Metrics: Time-series data points about the elb stats; regular intervals
- Logs: Info regarding requests to the load balancer; event-specific