AWS DEVOPS : Cheat Sheet

Ec2

• AMI, Type, Storage, Networking, optional settings
• Tenancy: Shared , Dedicated, Dedicated Host
• You can make a template with another template as source
• System Status Check :These checks detect problems with your instance that require AWS involvement to repair
  • Loss of network connectivity
  • Loss of system power
  • Software issues on the physical host
  • Hardware issues on the physical host that impact network reachability
• Instance status checks: These checks detect problems that require your involvement to repair
  • Failed system status checks
  • Misconfigured networking or startup configuration
  • Exhausted memory
  • Corrupted file system
  • Incompatible kernel

• Status checks are performed every minute, returning a pass or a fail status. If all checks pass, the overall status of the instance is OK. If one or more checks fail, the overall status is impaired. Status checks are built into Amazon EC2, so they cannot be disabled or deleted. 

Auto Scaling Group 

-Detail : Lauch template, network, 

– Notification: SNS

– Automatic Scaling :

• Dynamic scaling policies: target tracking, Step scaling, Simple scaling on basis of CPU utilization, network, alb request count per target
• Predictive Scaling
• Scheduled action

– Instance management: instance , lifecyle hooks, warm pool

– Instance : detach , set to standby, set to service, Set scale-in protection, remove scale-in protection

– life cycle hook : for custom action : launch : terminate

– warm pool : pre setup instance

– Monitoring : ec2 and auto scaling groups

– Instance refresh : Start an instance refresh to perform rolling updates on the Auto Scaling group’s instances. Only one instance refresh can be active at a time.

– EC2 Auto Scaling automatically replaces instances that fail health checks [Amazon EC2 Status check]. : always enabled

-Amazon EC2 Auto Scaling gracefully detaches the impaired instance from the load balancer. Then it launches a new instance and attaches it to the load balancer.

-If you want that an instance should be replaced if ALB reports a health check failure, then it needs to enabled. otherwise, ASG will not take any action of health check failed instance however if instance is not health ALB will stop direcitng the request to that.

– we can suspend some processes like

• Launch, terminate, healthcheck, replace unhealthy, az rebalance, alarm , scheduled action, add to load balancer, instance refresh

-We can define termination policy as well.

– We can use ec2 with ASG for obtaining resilience or auto recovery

– An Auto Scaling group is associated with one launch configuration at a time, and you can’t modify a launch configuration after you’ve created it. Therefore, if you want to change the launch configuration for an existing Auto Scaling group, you must update it with the new launch configuration

– launch template has version and you set the default version to use

– ASG linked with capacity rebalancing, CF, CLodu shell, ELB, Event Bridge, VPX

Application Auto Scaling

• AppStream 2.0 fleets
• Aurora replicas
• Amazon Comprehend document classification and entity recognizer endpoints
• DynamoDB tables and global secondary indexes
• Amazon Elastic Container Service (ECS) services
• ElastiCache for Redis clusters (replication groups)
• Amazon EMR clusters
• Amazon Keyspaces (for Apache Cassandra) tables
• Lambda function provisioned concurrency
• Amazon Managed Streaming for Apache Kafka (MSK) broker storage
• Amazon Neptune clusters
• SageMaker endpoint variants
• Spot Fleet requests

AWS DEVOPS : Cheat Sheet