Web Application Performance Design Inspection Questions

- J.D. Meier, Srinath Vasireddy, Ashish Babbar, Rico Mariani, and Alex Mackman

Deployment and Infrastructure

• Do you need a distributed architecture?
• What distributed communication should you use?
• Do you have frequent interaction across boundaries?
• What restrictions does your infrastructure impose?
• Do you consider network bandwidth restrictions?
• Do you share resources with other applications?
• Does your design support scaling up?
• Does your design support scaling out?

Caching

• Do you cache data?
• Do you know which data to cache?
• Do you cache volatile data?
• Have you chosen the right cache location?
• What is your expiration policy?

Class Design Considerations

• Does your class own the data that it acts upon?
• Do your classes expose interfaces?
• Do your classes contain virtual methods?
• Do your classes contain methods that take variable parameters?

Communication

• Do you use chatty interfaces?
• Do you make remote calls?
• How do you exchange data with a remote server?
• Do you have secure communication requirements?
• Do you use message queues?
• Do you make long-running calls?
• Could you use application domains instead of processes?

Concurrency

• Do you need to execute tasks concurrently?
• Do you create threads on a per-request basis?
• Do you design thread safe types by default?
• Do you use fine-grained locks?
• Do you acquire late and release early?
• Do you use the appropriate synchronization primitive?
• Do you use an appropriate transaction isolation level?
• Does your design consider asynchronous execution?

Coupling and Cohesion

• Is your design loosely coupled?
• How cohesive is your design?
• Do you use late binding?

Data Access

• How do you pass data between layers?
• Do you use stored procedures?
• Do you process only the required data?
• Do you need to page through data?
• Do your transactions span multiple data stores?
• Do you manipulate BLOBs?
• Are you consolidating repeated data access code?

Data Structures and Algorithms

• Do you use appropriate data structures?
• Do you need custom collections?
• Do you need to extend IEnumerable for your custom collections?

Exception Management

• Do you use exceptions to control application flow?
• Are exception handling boundaries well defined?
• Do you use error codes?
• Do you catch exceptions only when required?

Resource Management

• Does your design accommodate pooling?
• Do you acquire late and release early?

State Management

• Do you use stateless components?
• Do you use .NET remoting?
• Do you use Web services?
• Do you use Enterprise Services?
• Have you ensured objects to be stored in session stores are serializable?
• Do you depend on view state?
• Do you know the number of concurrent sessions and average session data per user?