A load balancer is essentially a set of traffic engineering rules that are coming into the Google network, and VPC is applying your rules destined to your IP address subnet range.
Assign an IP to the LB then fetch from that LB to use it
instance → disk → image → instance template → instance group → backend service+health check → application load balancer
Provides cross-region load balancing including automatic failover
applications are available to your customers at a single anycast IP address, which simplifies your DNS setup.
Must use passthough for preserving IP address of client
Global load balancers:
Global external HTTP(s)
cross-regional load balancing for a web application
External HTTP(s) load balancing (classic)
External SSL proxy:
for Secure Sockets Layer traffic that is not HTTP
If it’s other TCP traffic that doesn’t use SSL
External TCP proxy
Regional load balancer: to load balance UDP traffic, or traffic on any port number, you can still load balance across a Google Cloud region
Regional internal load balancer: load balance traffic inside your project, say, between the presentation layer and the business layer of your application
Google Cloud Internal HTTP(S) Load Balancing is a proxy-based, regional Layer 7 load balancer that also enables you to run and scale your services behind an internal load balancing IP address.
When a user request comes in, the load balancing service determines the approximate origin of the request from the source IP address.
Cross-region load balancing:
If there are no healthy instances with available capacity in a given region, the load balancer instead sends the request to the next closest region with available capacity.
Common use case is: send requests for dynamic content to a backend service; static content to a backend bucket.
Routing rules:
Determine how your traffic will be directed depemds on the host and path
For example, some IP sends to somewhere and /video sends to different backend service
Network Load Balancer (TCP/SSL)
SSL proxy:
For encrypted non-HTTP traffic.
Terminates user SSL connections at the load balancing layer
then balancer establish new connections to backend instances using the SSL or TCP protocols.
SSL recommended
Both Ipv4 and IPv6
TCP proxy:
For unencrypted, non-HTTP traffic.
Terminates your customer’s TCP sessions at the load balancing layer
then forwards the traffic to your virtual machine instances using TCP or SSL.
Both Ipv4 and IPv6
Network Load Balancer
Regional
Non-proxied, the traffic passes through the load balancer instead
the traffic can only be balanced between VM instances that are in the same region
Network Load Balancer (UDP/Multiple protocols)
Can use it to load balance UDP traffic and to load balance TCP and SSL traffic on ports that are not supported with the TCP proxy and SSL proxy load balancers.
