Load Balancers

Question 1

GCP’s NLB vs HLB - Region / Cross-Region. Explain each

Answer 1

NLB Supports only within a region. Operates on layer 4. Does not support cross-region load balancing

HLB Support both within cross-region. Operates on layer 7.

Question 2

GCP’s NLB vs HLB - Load Balancing is based on…. Explain each

Answer 2

NLB is based on IP address, port and protocol type. Any TCP/UDP traffic, even SMTP can be load balanced.

HLB is based only onHTTP and HTTPS protocols.

Question 3

GCP’s NLB vs HLB - Packet inspection. Explain differences

Answer 3

NLB’s packet inspection is possible and load balance is based on packages

HLB cannot inspect packets as these are produced or managed on level 4

Question 4

GCP’s NLB vs HLB - Instance Group. Explain each

Answer 4

NLB: No need of creatinginstance group. Target pools need to be created. Instance can be just tagged to the pool. Ideal for unmanaged instance grou where instances are non homogeneous.

HLB: Managed / UnManaged Instance group is necessary for creating HTTP/HTTPS load balancer

Question 5

GCP’s NLB vs HLB - Workflow. Explain each

Answer 5

NLB: Forwarding rules is the starting point. It directs the request to the target pools from which compute engines will pick the request.

Forwarding rules -> target pool -> instances

HLB: This is quite complex in HTTP(s) load balancer. Global forwarding rules routes direct the request to target HTTP proxy, which in turn checks the URL map to determine appropriate backend services. These services in turn direct the request to the instance group.

Global forwarding rules -> Target HTTP proxy -> URL map -> Backend services -> Instance group

Question 6

GCP’s NLB vs HLP - Types of Load Balancers. Explain each

Answer 6

NLB: Basic network load balancer which directs the request based on IP address, port and the protocol within the region.

HLB: 1. Cross-region load balancer uses only one global IP address and routes the request to the nearest region.
2. Content-based load balancer is based on the URL path. Different path rules need different backend services. for ex: /video and /static require 2 separate backend services.

Question 7

GCP’s NLB vs HLB - Session affinity. Explain each

Answer 7

NLB: Session affinity can be set, but only during the creation of target pool. Once it is set, the value cannot be changed.

HLB: 1. Client IP Affinity: This directs the same client IP to same backend instance by computing hash of the IP.
2. Generated Cookie Affinity: Load balancer stores cookie in clients and directs the same client to same instance with the help of retrieved cookie.

Question 8

GCP’s NLB vs HLP - Health Check. Explain each

Answer 8

NLB: Health check is optional, but network load balancing relies on HTTP Health checks for determining instance health.

HLB: Health can be verified by either using HTTP health check or HTTPS health check.

Question 9

What is GCP Target Pool?

Answer 9

Target pools are regional resources which may contain compute instances across multiple zones within a single region. Each Google Cloud project may have up to 50 target pools.

Question 10

What is Cloud Load Balancing? What are the 2 main options?

Answer 10

A load balancer distributes user traffic across multiple instances of your applications. By spreading the load, load balancing reduces the risk that your applications experience performance issues.

Cloud Load Balancing offers a comprehensive portfolio of application and network load balancers.

Question 11

What’s Global proxy load balancer used for?

Answer 11

Use our global proxy load balancers to distribute millions of requests per second among backends in multiple regions with our Google Front End fleet in over 80 distinct locations worldwide—all with a single, anycast IP address.

Question 12

What’s Regional proxy load balancer used for?

Answer 12

Implement strong jurisdictional control with our regional proxy load balancers, keeping your backends and proxies in a region of your choice without worrying about TLS/SSL offload.

Question 13

What are passthrough load balancers used for?

Answer 13

Use our passthrough load balancers to quickly route multiple protocols to backends with the high performance of direct server return (DSR).

Question 14

What’s a Single anycast IP address?

Answer 14

frontend for all of your backend instances in regions around the world. It provides cross-region load balancing, including automatic multi-region failover, which moves traffic to failover backends if your primary backends become unhealthy. Cloud Load Balancing reacts instantaneously to changes in users, traffic, network, backend health, and other related conditions.

Question 15

What’s Software-defined load balancing?

Answer 15

Cloud Load Balancing is a fully distributed, software-defined, managed service for all your traffic. It is not an instance-based or device-based solution, so you won’t be locked into a physical load-balancing infrastructure or face the high availability, scale, and management challenges inherent in instance-based load balancers.

Question 16

What can we use Layer 4 for?
and Layer 7 load balancing is used for?

Answer 16

Use Layer 4-based load balancing to direct traffic based on data from network(3) and transport(4) layer protocols such as TCP, UDP, ESP, GRE, ICMP, and ICMPv6 .

Use Layer 7-based load balancing to add** request routing decisions based on attributes, such as the HTTP header and the uniform resource identifier(URI**).

Question 17

When can you use Internal load balancing? and External load balancing?

Answer 17

You can use internal load balancing when your clients(other services, users) are inside of Google Cloud.

You can use external load balancing when your users reach your applications from the internet.

Question 18

What other name is HTTP Load Balancer known as? These can be…

Answer 18

Application Load Balancers are proxy-based Layer 7 load balancers that enable you to run and scale your services behind a single IP address.

They can be Internal and External load balancers