Load Balancing and Autoscaling

Question 1

Cloud Load Balancing is

Answer 1

a fully distributed, software-defined managed service which gives the ability to distribute load-balanced compute resources in single or multiple regions to meet your high availability
requirements, to put your resources behind a single anycast IP address and to scale your resources up or down with intelligent autoscaling.

Question 2

different types of load balancers

Answer 2

GCP offers different types of load balancers that can be divided into two categories, global and regional.
The global load balancers are the HTTP, HTTPS, SSL proxy and TCP proxy load balancers.
The regional load balancers are the internal and network load balancers:
internal TCP/UDP, network TCP/UDP, internal HTTP/HTTPS

Question 3

A managed instance group ?

Answer 3

A managed instance group is a collection of identical VM instances that you control as a single entity using an instance template.
You can easily update all the instances in a group by specifying a new template in a rolling update.
Also when your applications require additional compute resources, managed instance groups can scale automatically to the number of instances in the group.

Question 4

what they are used for

Answer 4

Managed instance groups can work with load balancing services to distributor network traffic to all of the instances in the group.
Managed instance groups can automatically identify and recreate unhealthy instances in a group to ensure that all instances are running optimally.

Question 5

How can managed instance group identify unhealthy instance

Answer 5

using a health check

Question 6

Which are Applicable autoscaling policies

Answer 6

Applicable autoscaling policies include scaling based on
1. CPU utilization,
2. load-balancing capacity
3. monitoring metrics or via queue-based workload like Cloud PubSub

Question 7

Which metrics you can monitor on your instance group

Answer 7

CPU utilization over the past hour, but you can change the time frame and visualize other metrics like disk and network usage.
You can even set up alerts through several notification channels.

Question 8

how to define a health chek

Answer 8

You define a protocol, port and health criteria
criteria defines:
- how often to check whether an instance is healthy.That’s the check interval.
- how long to wait for a response, that’s the time-out.
- how many successful attempts are decisive, that’s the healthy threshold.
- how many failed attempts are decisive, that’s the unhealthy threshold.

Question 9

about HTTPS load balancing

Answer 9

HTTPS load balancing which acts at layer seven of the OSI model.
00:06
This is the application layer which deals with the actual content of each message allowing for routing decisions based on the URL.

Question 10

GCPs HTTPS load balancing main features

Answer 10

• provides global load balancing for HTTPS requests (applications are available at a single Anycast IP address)
• balances HTTP and HTTPS traffic across multiple regions.
• HTTP requests are load balanced on port 80 or 8080 and HTTPS requests are load balanced on port 443.
• supports both IPv4 and IPv6 clients
• is scalable
• requires no prewarming
• You can configure URL maps that route some URLs to one set of instances and route other URLs to other instances.

Question 11

What are global load balancers

Answer 11

HTTP, HTTPS, SSL proxy, TCP proxy
These load balancers leverage the Google front ends, which are software-defined, distributed systems that sit in Google’s point of presence and are distributed globally.

Question 12

What are regional load balancers

Answer 12

The regional load balancers are the internal and network load balancers, and they distribute traffic to instances that are in a single GCP region.

Question 13

what type of instance group you can create

Answer 13

managed stateless instance group
managed stateful instance group
unmanaged instace group

Question 14

cross-region load balancing

Answer 14

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.

Question 15

HTTPS load balancers based by balancing strategy?

Answer 15

1. locations & capacity based lb
2. content-paste load balancer.

Question 16

HTTP(S) load balancer has the same basic structure as an HTTP load balancer, but it differs in:

Answer 16

1. An HTTP(S) load balancer uses a target HTTPS proxy instead of a target HTTP proxy.
   2.An HTTP(S) load balancer requires at least once signed SSL certificate installed on the target HTTPS proxy for the load balancer.
   3.The client SSL sessions terminate at the load balancer.
   4.HTTP(S) load balancers support the QUIC transport layer protocol.

Question 17

what is necessary for https lb

Answer 17

1. you must create at least one SSL certificate that can be used by the target proxy for the load balancer.
   You can configure the target proxy with up to 15 SSL certificates.
   SSL certificate resources are used only with a target HTTPS proxy or target SSL proxy,

Question 18

Backend buckets allow you to use Google Cloud Storage buckets with HTTP(S) Load Balancing. Common example

Answer 18

One common use case is: send requests for dynamic content, such as data, to a backend service; and send requests for static content, such as images, to a backend bucket.

Question 19

NEG is ?

Answer 19

is a configuration object that specifies a group of backend endpoints or services.
A common use case for this configuration is deploying services in containers.