aws

https://youtu.be/VIgAT7vjol8

Elastic Load Balancing: Deep Dive and Best Practices - 2018

Layer 4 and Layer 7 Load balancing difference,
- Layer 4 support TCP; Layer 7 only support http and https(will terminate the TLS)
- Layer 7 Connection will be terminated and pooled
- Layer 7 Headers can be modified
- X-Forwarded-For http header will be modified
Product mapping
- Application LB is layer 7 LB; Network LB is layer 4 LB

ALB support Path and host based routing (single ELB dispatch all traffic) ; deep integration with EKS – Micro Service Archi
ALB can do Redirects ; Fix response ; Slow start (configurable like 10 min) ; ALB IPV4 and V6 support;
ALB update certs
- IAM to control who have access to update
- Use ACM (AWS Certificate Manager) to directly push and rotate certs with ALB
Integrate with AWS WAF
Server Name Indication (SNI) : load balancing multiple applications that have muti certs
Authentication at ALB layer (OIDC, Cognito, SAML)
Muti-AZ (by default) and no extra bandwidth charge ;
Absorbs impact of DNS caching (?)
Health check ; recommend to use http code to check; work with auto scaling

Million Level request / second
Static IP for each AZ
- Firewall example: 2 layers of NLB ; fewer static ip simplified the firewall config
- Route 53 will route to multiple static ip addresses in different AZ.
Support Proxy Protocol V2
Cloudwatch metrics for NLB : it has flow log