Aug 16 2010

ASP.NET best practices

Category: Uncategorized — zvolkov @ 4:00 pm

Just a list of things I had at the top of my mind. There may be a few ones I missed and a few more obscure ones, but these should be the majority of the most important best practices.

  • Maintainability and time-to-market
    • Modular architecture
      • MVVM
      • IoC/DI
      • S.O.L.I.D.
      • ORM for data access (NHibernate, Entity Framework)
      • SOA only for Ajax and for true business services (not for plain vanilla data access)
      • Command/Query separation aka PRG: post-redirect-get
      • Needless to say, keep most classes free from references to ASP.NET objects
    • Automated pro- and regression testing
      • Automated compilation and test execution on schedule or on check-in
      • Unit-tests (anything except MsTest, e.g. MbUnit)
      • Code coverage measurement. Code coverage never goes down policy.
      • UI tests (Selenium + RobotFramework)
    • Automated deployment
      • On-click deployment from the get-go. No manual error-prone steps.
      • WiX- or MSDeploy- based deployment
      • Automated post-deployment testing
      • Strive for transparent no-downtime deployment
        • Ensure that deployment does not interrupt users currently using the site
        • Precompile code to prevent compilation slowdown
    • Coding practices
      • No VB.NET, only C#
      • FxCop, NDepend to monitor coding standards
      • Most importantly: no huge pages, no long methods, no monster classes
    • Best of breed tools and technology for increased development productivity
      • ASP.NET MVC – no WebForms
      • ReSharper
      • LESS CSS
      • CSS Layout  frameworks
      • JQuery
      • YUI or other GUI component library
  • Performance/Scalability
    • Defined performance requirements: throughput (reqs / sec), response time (page load time, time to complete basic operations), peek capacity (simultaneous users not necessarily clicking at the same time) etc.
    • Automated measurement of load and performance metrics (record Windows PerfMon counters and make available on a website)
    • Caching (at ORM level, at viewmodel level (memcached?), at page level (native IIS caching))
    • Enable gzip/deflate compression for both static and dynamic content
    • Async ASP.NET pages for long-running requests
    • Distributed in memory Session provider (no DB based)
    • Auto-minify javascripts & stylesheets
    • Make sure pages are compiled in release mode
    • Disable tracing
    • Avoid LINQ when working with large data sets
    • Use ORM profiling to ensure minimum interaction with RDBMS
    • Validate pages using YSlow and implement basic optimizations (javascript at the bottom, css in the HEAD etc.)
    • Implement load balancing using a web farm
    • Improve perceived performance by implementing a job queue system for long running operations (reports etc.)
    • Minimize use of ViewState
    • Validate controls on the client side
    • Use [Conditional] attribute for debug logging
    • Never return unlimited dataset
  • Uptime & problem management
    • Defined SLA
      •  Required uptime window
      • Maintenance (designated downtime) window
    • Automated measurement of uptime metrics
      • % uptime against defined SLA
      • Mean time between failures
      • Time to recover operations
    • Problem detection
      • Automated health monitoring (aka pinging, live smoke-testing)
        • Using Selenium / Robot Framework
      • Error reporting
        • Use Elmah to report unexpected exceptions
    • Troubleshootability
      • Logging using log4net
      • Install Failed Request Tracing module and know how to use it
    • Failproof system
      • Analyze and avoid single point of failure
      • Implement failover clustering
  •  Usability and user experience
    • Multi browser support
      • Test functionality in multiple browsers
      • Use reset style sheet
      • Use frameworks that isolate from browser differences (JQuery, CSS layout frameworks, component libraries)
    • Back button support and Refresh-button tolerance
      • Back-friendly URLs (using MVC route maps)
      • Command/query separation
    • Simplify complaints / feedback
    • Implement user-friendly error messages
  • Security
    • HTTPS with real certificate (not self-signed)
    • License an automated software suite to test against SQL injection, XSS, XSRF, session hijacking, etc
    • Use an off the shelf authentication / authorization system, never design your own
    • Hire a hacker once a year

Aug 12 2010

Vim resources

Category: Uncategorized — zvolkov @ 1:00 pm

Just a bunch of links.

Vim tutorial for beginers

More advanced stuff

How to navigate around C source files in Vim and invoke the compilation from Vim

Even more tricks for programmers

Vim keyboard stickers

Vim screencast