Agile, agile and to production

For Lviv .Net Community event "Fuckup Nights"

Transcript

1. ajukraine ajukraine Bohdan Makohin Tech Lead at Interlogic https://t.me/ajukraine
2. 05 / 12 / 2018 07 / 12 / 2018
4. Chapter I. RTFM
6. [HttpPost] public ActionResult ChangeSettings(SettingsRequest settingRequest) { LinqToSQLDataContext db = Database.Context; Setting setting = db.Settings .FirstOrDefault(s => s.Key == settingRequest.Key); setting.Value = settingRequest.Value; db.SubmitChanges(); return View(); } Spot the lethal
7. [HttpPost] public ActionResult ChangeSettings(SettingsRequest settingRequest) { using (LinqToSQLDataContext db = Database.CreateContext()) { Setting setting = db.Settings .FirstOrDefault(s => s.Key == settingRequest.Key); setting.Value = settingRequest.Value; db.SubmitChanges(); return View(); } } stay HUNGRY stay FOOLISH
8. Lesson time üUse pattern “Unit of work” üAvoid static variables üTake care of unmanaged resources
9. Chapter II. Trust, but verify
10. üLot of “client disconnected exception” üNormal latency of Input/Output üRepeats with similar time intervals Symptoms
12. Lesson time üAlways check external libraries üUse application profilers üOnion approach to investigate complicated problems
13. Chapter III. The Butt-erfly Effect
15. üHTTP queue is overloaded üGarbage Collector spends ~80% of CPU time üDiagnostics metrics are not consistent Symptoms
17. Lesson time üMinimize number of blocking dependencies üPerform smart load tests