Cloud Application Architecture: Hosting & Things to Remember
By Shantanu Kaushik
A generic application or a web application in a traditional web hosting mostly always proves to be a challenge. Be it the design structure or a scalable architecture to support trends and demands. A typical hosting scenario follows a three-tier architecture and divides it within presentation, persistence and application layer. With a high-availability feature built-in, this design scenario achieves high scalability by using additional servers within each of the said layers. Taking this traditional application architecture and using various Alibaba cloud tools to deploy these applications provides the user an ability to leverage the true value or such applications and extract proper business benefits.
Alibaba Cloud application architecture cuts down on most of the steps that are required within the traditional system, namely installation, management and maintenance associated with the hardware infrastructure. With that in today’s world, large enterprises are scattered in multiple locations and managing there without a cloud-based application architecture incurs huge costs and overheads.
Cloud application architecture with Alibaba Cloud ensures SLAs that are required for high availability needs. The Simple Application Server by Alibaba Cloud provides architecture that outperforms many providers in India and overseas with lightning fast storage and servers.
Let’s look at the Alibaba Cloud web hosting architecture to understand the flow and architecture a little bit better. The diagram below represents the actual workflow and architecture:
Let us talk a little about the components that are part of this architecture:
Elastic Compute Service (ECS)
With highest SLA commitment, Alibaba Cloud ECS provides multiple availability zones to cloud providers across the world. Based on a large-scale distributed computing system, Alibaba ECS is highly efficient and scalable. Alibaba ECS includes the in-house developed X-Dragon compute platform alongside the Dragonfly lightweight hypervisor. The capability of providing hundreds of thousands of vCPUs within minutes to a single user in a single region is unmatched. This smart WEB+ platform by Alibaba, helps you to build stable and secure web applications based on the business needs.
Relational Database Service (RDS)
This Relational Database Service (RDS) has been developed by Alibaba to be one of the most elastic, high-performance and stable database services. While providing most of the standard RDS features, Apsara DB supports OceanBase, PolarDB, MySQL, PostgreSQL, SQL Server, PPAS, MariaDB TX and among others. Moreover, Alibaba now provides Apsara DB for MongoDB, venturing further into supported Database platforms.
Server Load Balancer (SLB)
Server Load Balancer by Alibaba Cloud seamlessly distributes traffic across servers hence distributing the traffic load to maintain proper functionality pan-platform. It manages the web traffic in a way that no single point failure can take place, eliminating SPOFs — Single Point of Failures. Alibaba Cloud SLB supports layer-4 load balancing over TCP or UDP (Source IP based) and Layer-7 balancing over HTTPS or HTTP (cookie based), hence extending the service capabilities of your applications.
Object Storage Service (OSS)
With a guaranteed durability of 99.9999999999%(12 9's), Alibaba Cloud Object Storage Service provides a seamless, encrypted, extremely fast and reliable storage backup and archiving capabilities. RESTful APIs count for easy access from anywhere through Internet. With a capability of automatic data replication and recovery, your applications uptime will be unmatched.
Things to Remember: Deployment with Alibaba Cloud
Deploying your applications using Alibaba Cloud can give you unmatched benefits. While doing so consider the following points to fully utilize the capability of Alibaba Cloud to deploy your application.
Alibaba Cloud has state-of-the-art security solutions like WAF (Web Application Firewall), Server Guard, Anti-DDOS Basic and Pro, and a dedicated Security Center. These products by Alibaba Cloud ensure the utmost secure environment to host applications as a majority of application vulnerability issues are addressed by these products.
Using Server Guard, you can limit or control the flow of traffic by defining firewall rules and exceptions at an ease. While accessing a web server cluster, a pre-defined firewall rule only allows access to port 80 and 443 (http / https request) and to further protect the application server, the security group rule only allows access through web servers.
Let us look at this flow diagram to understand how the information is controlled:
For DB servers, the predefined security group allows access to the application data and only permits access through the application layer with a direct host management through Port 22 (SSH). You can further configure this group to allow whitelisted IP address to get access through the firewall.
Alibaba Cloud defines Availability Zones and makes sure that at least two data centers are allocated for a single region. Within an ECS, different zones are separated by these Availability Zones but Alibaba Cloud provides a very easy model to deploy your applications across the AZs to allow for higher availability and elasticity.
Building application for the cloud requires a platform that is in itself dynamic and understands the concept of availability and reliability. Alibaba ECS does exactly that. While deploying applications, Alibaba Cloud permits the users to select location of your resources and with that it provides Elastic IP addresses. This solves the certainty issues that are very common when deploying an application. The Simple Application Server by Alibaba Cloud manages and decouples the flow of information from front-end to back-end and vice-versa to maintain a secure and reliable form of communication.
Let’s take a scenario on a failure. In this case all your resources may become unavailable. Now, when a new virtual server is allocated, what region and IP will be assigned to it is more likely guess work. Here Alibaba Cloud comes in and provides Elastic IP and resource location preference to the user, overcoming this issue. Even if you churn in a new ECS instance, you can simply map the Elastic IP to the new ECS instance. This accounts for a scalable and fault resistive application build and hosting.
When building applications or migrating them, the first and foremost rule of thumb should be to decide on a cloud provider that supports and understands the need of the hour. This need can be very simple out-drafted as a secure, scalable and reliable host that can provides state of the art security, fault tolerance and backup services. Alibaba Cloud as a market leader in Cloud services today provides just that. For reference, checkout Alibaba Cloud’s starter packages on this link.