Google Cloud Load Balancing is a fully distributed, software-defined managed service. It provides scaling, high availability, and traffic management for internet-facing and private applications.
This blog covers an overview of load balancing, load balancing options offered by Google, and how to select the correct load balancer.
Now before we dive into the topic let’s understand what is load balancing and why is it important.
Load balancing is the process of distributing traffic across your network of servers to ensure that the system does not get overwhelmed and all requests are handled easily and in a more efficient manner. Cloud Load Balancing is a fully distributed, software-defined managed service.
Cloud Load Balancing allows you to put your resources behind a single IP address that is externally accessible or internal to your Virtual Private Cloud (VPC) network.
There are a number of reasons why load balancing is important. Load balancer allows users to:
With Google Cloud Load Balancing, users can serve content as close as possible to their customers, on a system that can respond to over 1 million queries per second!
Both the above types of load balancing options are further categorized into internal or external depending upon the type of traffic being served.
Let’s look into each of these categories in detail.
Global load balancing is a practice of distributing traffic across connected server resources that are located in different geographical regions and distributing the workload globally instead of having it in a single data center. It offers enhanced traffic management and disaster recovery benefits to optimize the performance of an application. Google Cloud Global load balancing provides IPv6 termination and uses the use the premium tier of network service tiers
Regional Load balancing allows users to split their workload via a pool of servers located in the same region. It is used when your backends are in one region, and you only require IPv4 termination.
2.) Internal vs External Load Balancing
External load balancing supports Instance groups, Zonal network endpoint groups (NEGs), buckets in Cloud Storage, serverless NEGs, and internet NEGs. It can be used to support web, application, and database tier services.
It offers the following load balancing options:
- External HTTP(S) Load Balancing
- SSL Proxy
- TCP Proxy
- TCP/UDP Network Load Balancing
Internal load balancing is a managed service that can only be accessed on an internal IP address and in the chosen region of your Virtual Private Cloud network. At a high level, it consists of one or more backend services to which the load balancer forwards traffic and an internal IP address to which clients send traffic. It can be used to run the applications behind an internal IP address and disperse HTTP/HTTPS traffic to the backend application hosted either on Google Kubernetes Engine or Google Compute Engine. You can use it to route and balance load traffic to your virtual machines.
It offers the following load balancing options:
- Internal TCP/UDP Load Balancing
- Internal HTTP(S) Load Balancing
3.) Network Load Balancing
Network load balancing or Google Cloud external TCP/UDP Network Load Balancing is a regional, pass-through load balancer. It distributes TCP or UDP traffic among virtual machine (VM) instances in the same region. It can receive traffic from the following sources:
- Client on the internet
- Google Cloud VMs with external IPs
- Google Cloud VMs with internet access through Cloud NAT or instance-based NAT
4.) HTTP(S) Load Balancers
Google Cloud HTTP(S) Load Balancing is a global, proxy-based Layer 7 load balancer that enables users to run and scale their services worldwide behind a single external IP address. There are 2 types of HTTP(S) Load Balancers:
- Internal HTTP(S)
- External HTTP(S)
5.) Proxy-based Load Balancers (TCP & SSL)
Google Cloud also offers proxy-based load balancers forTCPandSSLtraffic, and they use the same globally distributed infrastructure.
TCP Proxy Load Balancing: It is a reverse proxy load balancer that distributes TCP traffic coming from the internet to virtual machine instances in the Google Cloud VPC network. It lets customers use a single IP address for all their users worldwide. The TCP proxy load balancer automatically routes traffic to the backends that are closest to the user.
SSL Proxy Load Balancing: It s a reverse proxy load balancer that distributes SSL traffic coming from the internet to virtual machine instances in the Google Cloud VPC network.
Components Of Google Cloud Load Balancing
1.) Backend Services: A backend service defines how the Cloud Load Balancing distributes traffic. The configuration contains a set of values like the protocol used to connect to backends, various distribution and session settings, health checks, and timeouts.
A backend is a group of endpoints that receive traffic from the Google Cloud load balancer, a Traffic Director-configured Envoy proxy, or a proxy less gRPC client.
2.) Health Checks: Google Cloud provides health checking mechanisms that determine if backends, such as for instance groups and zonal network endpoint groups (NEGs), properly respond to traffic.
3.) SSL Certificates: Google Cloud uses SSL certificates to provide privacy and security from a client to a load balancer. Transport Layer Security (TLS) is an encryption protocol used in SSL certificates to protect network communications.
4.) IPv6 Termination: IPv6 termination enables you to handle IPv6 requests from your users and proxy them over IPv4 to your backends.
How Does Load Balancing Work In Google?
Let’s look at a simple use case to understand how internal and external load balancing works together.
The diagram below illustrates the use case: traffic from users in San Francisco, Iowa, and India is directed to an external load balancer, which distributes that traffic to different regions in a Google Cloud network. Two internal load balancers distribute traffic within the two regions: us-central1 and asia-south1. Within us-central1, that internal load balancer distributes traffic between two zones: us-central1-a and us-central1-b.
How To Choose The Right Load Balancer In Google Cloud?
Now that we have seen what is load balancing and its types, the question that comes to our mind is how do we select the correct load balancing option from the various options available?!
To decide which load balancer best suits your implementation of Google Cloud, consider the following aspects of Cloud Load Balancing:
- Global versus regional load balancing
- External versus internal load balancing
- Traffic type
After you determine whether you need global or regional load balancing, external or internal load balancing, and what traffic type your load balancers must handle, use the following flow chart to determine which load balancers are available for your client, protocol, and network configuration.
With this flowchart, you can select the right load balancer as per your requirement.
Frequently Asked Questions
How can I monitor and troubleshoot load balancing in GCP?
GCP provides monitoring and logging capabilities through services like Stackdriver, which allow you to monitor the performance, health, and metrics of your load balancers. Additionally, GCP provides extensive documentation and troubleshooting guides to help diagnose and resolve any issues.
Are there any additional features provided by GCP Load Balancers?
Yes, GCP Load Balancers offer additional features, such as SSL/TLS termination, SSL policy management, health checks for backend instances, content-based routing, and access controls. These features enhance security, performance, and control over the load balancing setup.
Can load balancers in GCP span multiple regions?
Yes, GCP Load Balancers can be configured to span multiple regions. This allows for global load balancing, where traffic is distributed to the nearest healthy backend instance or service, regardless of its location.
How does load balancing work in GCP?
Load balancing in GCP operates by assigning a single external IP address to the load balancer, which then distributes incoming traffic to the backend instances or services based on configured load balancing rules, such as round-robin, session affinity, or load balancing algorithms.
Related References
- GCP Associate Cloud Engineer: All You Need To Know About
- Google Associate Cloud Engineer: Step-by-Step Hands-On
- Google Cloud Free Account: Steps to Register for Free-trial Account
- Introduction To Google Cloud Platform
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