AWS Load balancers
ELB advantages:
- can distribute traffic across EC2 instances, containers, IP addresses, and Lambda functions
- also load balances to on-premises servers.
- HA
- You need to be sure is that the load balancer's targets are deployed across multiple Availability Zones.
- Scalability
- automatically scales to meet the demand of the incoming traffic
ELB components
ELB types
- application load balancer https/http, layer 7
- user authorisation
- Open ID connect
-
- Lightweight Directory Access Protocol (LDAP)
- Microsoft Active Directory
- rich metrics and logging
- redirects
- fixed response
- sticky sessions
- If requests must be sent to the same backend server because the application is stateful, use the sticky session feature.
- network load balancer tcp/udp, layer 4
- source IP address
- low latency
- sticky sessions
- static ip support
- elastic ip address support
- DNS failover
- gateway load balancer ip, layer 3,4
- HA for third-party virtual appliances
- gateway load balancer endpoints
- health checks
- monitoring using cloudWatch
- private connectivity: connects internet gateways, VPCs, and other network resources over a private network.
- streamlined deployments
Requirements to the target group
- health check mu be worked:
- two types of health checks:
- using TCP and marking the instance as available if the connection is successful
- Making an HTTP or HTTPS request to a webpage that you specify and validating that an HTTP response code is returned
References
- AWS EssentialsModule 6
- https://explore.skillbuilder.aws/learn/course/134/play/85854/aws-cloud-practitioner-essentials Module 2
- AWS website: Elastic Load Balancing features(opens in a new tab)
- AWS website: AWS Certificate Manager(opens in a new tab)
- AWS documentation: Authenticate users using an Application Load Balancer(opens in a new tab)
- AWS developer guide: How AWS WAF works(opens in a new tab)
- AWS blog: Introducing AWS Gateway Load Balancer(opens in a new tab)