SaaS, PaaS, IaaS often come to my mind when I talk about cloud. But when I want to talk about a clear definition, I just realize I need to organize my thoughts first. So today, I am gonna to neaten the information and thinking about SaaS in the way of Q&A.
1 What is SaaS?
- A new delivery model
- The applications are hosted and managed in a service provider’s data center
- The applications are paid based on the subscription
- The applications are accessed via a browser over an internet connection.
2 What to consider before moving application to the Cloud?
- Network needs: High bandwidth and low latency, but you don’t want to maintain it. “The more you can keep the data transfer within the application and not between the application and the screen, the more suitable your application is for the cloud.“
- Scaling needs: Cloud is best choice for resource on-demand applications
- Storage needs: With the storage service in Cloud, you don’t need to deal with the worse performance caused by storage side.
- Publicly used needs: Separation your inner network from outer network is best for security consideration.
3 What is the pros and cons of SaaS?
- pros : cost saving, scalability, reliability, accessibility, upgradeability
- cons: security, outage, compliance, integration, performance, data mobility
4 How to do SaaS right?
It is hard to answer it. I can just say, before moving application to cloud, three key things should be considered first.
- resilience: Everything is controlled in the service provider side, you cannot control and you don’t know. When there is a problem, you have to determine it is the problem of service provider or of your application. It would cost much time to diagnose. With a good integrated monitoring system, diagnosis work would be faster.
- integration: Integration among applications. Is it easy to integrate applications in Cloud? Are you going to rely on or use services from one providers or many providers? With different providers, how do you integrate your applications?
- performance: Performance always be the key aspect. Can the provider ensure 24*7*12 up-time?
5 Need a best practice of SaaS here. (TODO)