Revolutionising Retail with Go

In a competitive market, Sainsbury’s is on a technology transformation process which involves the adoption of Go and a journey to cloud based distributed systems at scale.

The talk covers why we are increasingly choosing Go to solve these problems, architectural decisions, common mistakes, technology stack and how this delivers highly available, distributed systems that need to interact with legacy systems.

Transcript

11. Not a start
26. Stock API Stock Service Payment Database Service Discovery Legacy Service API Gateway LB
27. service := micro.NewService( micro.Name("service.stock"), micro.Version("latest"), micro.Flags( cli.StringFlag{ Name: "config_file_path", EnvVar: "CONFIG_PATH", Usage: "Config file path", }, ), micro.Action(func(c *cli.Context) { config.File = c.String("config_file_path") }), ) proto.RegisterStockHandler(service.Server(), &handlers.Stock{}) ...
28. Stock API Stock Service Payment Database Service Discovery Legacy Service API Gateway LB
29. Stock API Clients
30. // Set up eventsHandler := events.NewEventHandler() go eventsHandler.Init() ..... // Receive event ..... eventsHandler.Receive <- events.Event{ Ref: &foo, Data: map[string]interface{}{ "foo": foo, "bar": bar, }, }
31. // Receive websocket connection .... conn := &events.Connection{ Ref: sku, Ws: ws, } eventsHandler.RegisterEvent(conn) <-conn.Done
32. func NewEventHandler() *Handler { return &Handler{ Receive: make(chan Event), Store: make(map[string]map[*websocket.Conn]*Connection), } }
33. func (h *Handler) Init() { for { event := <-h.Receive if event.Ref == nil { log.Printf("Ref not provided... %+v", event) continue } go h.BroadcastEvent(event, *event.Ref) go h.BroadcastEvent(event, "") } }
34. func (h *Handler) BroadcastEvent(event Event, ref string) { h.eventsLock.RLock() defer h.eventsLock.RUnlock() js, err := json.Marshal(event.Data) if err != nil { return } for _, conn := range h.Store[ref] { err := websocket.JSON.Send(conn.Ws, string(js)) if err != nil { conn.Ws.Close() return err } } }
35. github.com/chazsmi/socket-events github.com/chazsmi/stock-management-api github.com/chazsmi/stock-service