Skip to main content

Route 53 health check vs. ELB Target Group health check

Use ELB target group health check if the health check endpoint is a simple HTML webpage.

Use Route 53 health check if the health check endpoint makes a database query. This is because the Route 53 health check has an overall lower request count compared to the Target Group health check.

Comments

Post a Comment

Popular posts from this blog

AWS Route53 - Private Hosted Zone

Post a Comment
Read more

High availability (Multi-AZ) for Amazon RDS

There is something called failover technology in Amazon. AWS RDS's Multi-AZ deployment uses this technology. If you enable Multi-AZ for an RDS DB, say MySQL DB, RDS automatically creates a standby replica in a different AZ. If the primary DB instance is in AZ-1A, then RDS creates a standby replica in AZ-1B (for example). Suppose I add a new row to a table in the primary DB, then the same row is added, almost in the same time, in the standby replica. This is called as synchronous replication . Thus, standby replicas are useful during DB instance failure/ AZ disruption . How? Because, there is no need to create a backup later because the backup has already been created. This gives high availability during planned system maintenance. Normal backup  operation - I/O activities are blocked in the primary database  Automated backup operation (standby replica) - I/O activities are not blocked This standby replica is not similar to read replica (which is used for disaster recovery). S...
Post a Comment
Read more

Application Load Balancer (ALB)

The ALB spans all subnets in a VPC i.e., it is not inside a subnet but VPC. ALB is bound to Target Groups (TGs). TGs are bound to subnets.
Post a Comment
Read more