Cloud Systems Administration Project

The project aims to create a decentralized service using Google Cloud tools to deliver content globally with low latency through a Content Delivery Network (CDN).

Architecture

The architecture is divided into two main stages:

Requesting Server IPs: The client requests a list of IPs for servers closest to their location and makes content requests until a response is received. We divided the world into 10 regions, each with at least one Region Server.
Content Delivery: After obtaining the server IPs, the client interacts with these servers to request the content.

Boot Server

The Boot Server is implemented using Google Cloud Run with a Docker image running a Flask server in Python. Its functions include:

Returning Closest Server IPs: Queries Google Cloud for active VMs and returns a list of IPs, with load balancing using Round Robin.

result = compute.instances().list(project=project, zone=region).execute()
alive = [instance["networkInterfaces"][0]["accessConfigs"][0]["natIP"] for instance in result['items'] if instance.get("status") == "RUNNING"]

Managing Content: Generates a signed URL for uploading content to the main bucket, valid for 1 minute. For deleting content, the server directly removes files from the bucket. HTTPS is used for secure communication.

bucket = client.bucket("asc_europe-southwest1")
blob = bucket.blob(file)
url = blob.generate_signed_url(version="v4", expiration=datetime.timedelta(minutes=1), method="PUT")

Region Server

Each of the 10 regions has at least one Region Server. These are e2-micro VMs running a Flask application to serve files. Production readiness is ensured with Gunicorn and NGINX. A caching mechanism is used to store content for 1 hour. Auto-scaling is based on CPU usage, triggered when average usage exceeds 80%. HTTPS with self-signed certificates is used for secure connections.

openssl genrsa -out server.key 4096
openssl req -new -key server.key -out server.csr
openssl x509 -req -in server.csr -signkey server.key -out server.crt

NGINX configuration:

server {
    listen 443 ssl;
    server_name 34.175.243.40;
    ssl_certificate /etc/nginx/server.crt;
    ssl_certificate_key /etc/nginx/server.key;
    ...
}

Buckets

Buckets store files and are accessed by Region Servers. Permissions are set, and a JSON key is used for access. Changes in the main bucket are propagated to other buckets using Google Cloud Functions.

Costs

Google Storage

Price per Invocation

Invocations/Month	US$/Million
First 2 Million	Free
After 2 Million	$0.40

Bucket Costs

City/State	Region	US$ (GB/Month)
Iowa	us-central1	$0.020
São Paulo	southamerica-east1	$0.035
Frankfurt	europe-west3	$0.023
Madrid	europe-southwest1	$0.023
Sydney	australia-southeast1	$0.023
South Carolina	us-east1	$0.020
Oregon	us-west1	$0.020
London	europe-west2	$0.023
Mumbai	asia-south1	$0.023

Virtual Machines

We used 10 VMs, each in different locations, with scaling up to 10 VMs per region. Each VM has the following specs:

Name	Virtual CPUs	Memory	Price/Month	Location
e2-micro	2	1GB	$7.88	Madrid

Google Cloud Run

Cloud Run was chosen for its scalability and cost efficiency, charging only for actual usage. It handles VM scaling, load balancing, and request routing.

Cost Estimate

Assuming high load, with an average of 9 VMs per region:

VM Costs: 9 VMs x 9 regions x $7.88 = $638.28
Storage Costs: 10 TB/month x $0.023 = $230

Total estimated cost: $638.28 (VMs) + $230 (Storage) = $868.28

pmsantos29/cloud-admin