HTTP: Can we do Better?

How much does your application weigh when you build it using HTTP Constructs? Can you achieve the same availability and reliability using another alternatives?

Transcript

1. HTTP Can we do better?
2. How much does your application weigh?
3. Services
4. Services
5. Discovery • Overlay Networks • Registry/Reverse Proxying • Port Scanning • DNS
6. Discovery: Overlay Networks • Slow • Rather call it host/container discovery? • Probably use Docker - Swarm
7. Discovery: Registry • Etcd, consul, zookeeper • Oh no, another cluster?
8. • How do you add dynamic hosts? • Proxy could Crash? • How to find Proxies? • Connection Draining • Latency+ • Gateway Partitioning Discovery: Reverse Proxies
9. Discovery: DNS Based • No Port based Information • SRV is cool ◦ No one uses it • Some Languages don’t obey TTL. • Health-check remains external process.
10. Components of Discovery • Registry ◦ Dynamically Configurable • Registration ◦ Clients emit Events ◦ Registrar’s sees lack of events • Health Check ◦ Reachability ◦ Load ◦ Latency • Load Balancing ◦ Client side ◦ Server Side
11. • Server - Side ◦ Proxy ◦ Haproxy, httpd, consul, nginx etc. ◦ ALB, ELB • Client - Side ◦ Netflix OSS • Algorithm • Staleness Load Balancing ◦ Round Robin ◦ Weighted Round-Robin ◦ Random ◦ URL ◦ Least Connections ◦ Least Traffic ◦ Least Latency ◦ Recently Used.
12. Other Essentials • Request Tracing • Unified Logging • Error Reporting • Wildcard • HTTP Multicast, Broadcast?
13. Alternate?
14. Sample Service
15. HTTP Way
16. PubSub/Redis
17. PubSub Way
18. Gilmour-Libs /gilmour-libs
19. Service Responder func bindListeners(g *G.Gilmour) { opts := G.NewHandlerOpts() g.ReplyTo("action.login", echoReply, opts) } func main() { engine := G.Get(redis.MakeRedis("127.0.0.1:6379", "")) bindListeners(engine) engine.Start() }
20. Service Caller func echoRequest(engine *G.Gilmour, msg string) (string, error) { req := engine.NewRequest("action.login") resp, err := req.Execute(G.NewMessage().SetData(msg)) if err != nil { return "", err } var output string err := resp.Next().GetData(&output) if err != nil { return "", err } return output, nil }
21. Request Response CALLER SERVICE HELLO? ALOHA! WRONG NUMBER SENDER_ID CODE
22. No/Good Service Discovery • No querying discovery process • Call service and not servers
23. Load Balancing
24. Load Balancing - Then NOTIFICATION SERVER 1 REPLICATED LOAD BALANCER X.Y.Y.Z ? CALLER SERVICE REGISTER I, AM HEALTHY? NOTIFICATION SERVER 2 NOTIFICATION SERVER 3
25. Load Balancing : Now NOTIFICATION SERVER 2 GILMOUR MANAGER.NOTIFICATION NOTIFICATION SERVER 1 NOTIFICATION SERVER 3 MANAGER.NOTIFICATION MANAGER.NOTIFICATION CALLER SERVICE MANAGER.NOTIFICATION {“NOTIFICATION”: “DATA”}
26. No/Good Load Balancing • Has Capacity, Will Serve • Message delivered to one and all • Fittest node acquires lock first • No need for Connection draining
27. And, How?
28. Just this func bindListeners(g *G.Gilmour) { opts := G.NewHandlerOpts().SetGroup("exclusive") g.ReplyTo("echo", echoReply, opts) }
29. Tracing, much?
30. $: redis-cli MONITOR 1509330865.376313 [0 127.0.0.1:59770] "PUBSUB" "NUMSUB" "gilmour.request.echo" 1509330865.376388 [0 127.0.0.1:59768] "SUBSCRIBE" "gilmour.response.1643e3fc-6362-4a2d-853b-35e8447a63f2" 1509330865.376502 [0 127.0.0.1:59770] "PUBLISH" "gilmour.request.echo" "{\"data\":\"Hello: World\",\"code\":200,\"sender\":\"1643e3fc-6362-4a2d-853b-35e8447a63f2\"}" 1509330865.376764 [0 127.0.0.1:59718] "SET" "1643e3fc-6362-4a2d-853b-35e8447a63f2exclusive" "1643e3fc-6362-4a2d-853b-35e8447a63f2exclusive" "NX" "EX" "600" 1509330865.376928 [0 127.0.0.1:59718] "PUBLISH" "gilmour.response.1643e3fc-6362-4a2d-853b-35e8447a63f2" "{\"data\":\"Pong Hello: World\",\"code\":200,\"sender\":\"gilmour.response.1643e3fc-6362-4a2d-853b-35e8447a63f2\"}" 1509330865.377133 [0 127.0.0.1:59768] "UNSUBSCRIBE" "gilmour.response.1643e3fc-6362-4a2d-853b-35e8447a63f2"
31. Network practices, much?
32. How? # Server Side Timeouts opts := G.NewHandlerOpts().SetTimeout(500) g.ReplyTo("echo", echoReply, opts) # Client Side Timeouts opts := G.NewRequestOpts().SetTimeout(400) req := engine.NewRequestWithOpts("action.login", opts)
33. Logging
34. How? G.Logf("action.login %v", "message") G.Log("action.login")
35. Errors
36. What do you do with Errors • Status Code >= 300 is reported. • Policy can be: ◦ Publish ◦ Queue ◦ Ignore func (r *Redis) SetErrorPolicy(policy string) error { if policy != errorPolicyQueue && policy != errorPolicyPublish && policy != errorPolicyIgnore { return errors.New("Invalid policy")) } r.errorPolicy = policy return nil }
37. Error Sample
38. Asynchronous Architectures
39. HTTP won’t, but • Queues • Celery • SideKiq • Kafka • SQS • Pravega • Nats … Can
40. Asynchronous EVENT.POWER_UP EVENT.* EVENT.* GROUP: REVENUE FP SCALING PUSH MESSAGE SERVER ADS/MARKETINGS ERVER UNLOCK LEVEL BADGE SERVICE EVENT.* ADS/ MARKETING GAME GILMOUR (Redis PubSub) EVENT EVENT.BRIDGE_FALL FALL FROM BRIDGE FALL FROM BRIDGE FALL FROM BRIDGE GROUP: BRIDGE_FALL
41. Logging, Revisited
42. Service Responder func bindListeners(g *G.Gilmour) { opts := G.NewHandlerOpts() g.Slot("example.log", func(req *G.Request) { var msg string if err := req.Data(&msg); err == nil { log.Println(req.Sender(), "->", msg) } }, nil) }
43. Asynchronous Caller func sendLog(engine *G.Gilmour) { line := "WordCount" engine.Signal("example.log", G.NewMessage().SetData(line)) line := "Fetching Data" // err will be not nil, if Message for example.log was not received by anyone. _, err := engine.Signal("example.log", G.NewMessage().SetData(line)) }
44. Composition
45. • compose - service1 | service2 | composition3 • andand - service1 && service2 && composition3 • oror - service1 || composition2 || service3 • batch ◦ (service1; service2; service3) > out ◦ service1; composition2; service3 > out • parallel • lambda functions
46. Composition pipe := engine.NewPipe( engine.NewRequest("example.fetch"), engine.NewRequest("example.words"), engine.NewRequest("example.stopfilter"), engine.NewRequest("example.count"), engine.NewParallel( engine.NewRequest("example.popular3"), engine.NewRequest("example.popular4"), engine.NewRequest("example.popular5"), ), ) resp, err := pipe.Execute(G.NewMessage().SetData(url)) expected := []string{} err := resp.Next().GetData(&expected)
47. Composition batch := e.NewPipe( e.NewRequest("weather.fetch"), e.NewRequest("weather.group"), e.NewParallel( e.NewPipe( e.NewParallel( e.NewRequest("weather.min"), e.NewRequest("weather.max"), )), e.NewPipe( e.NewParallel( e.NewRequest("weather.min"), e.NewRequest("weather.max"), )))) resp, _ := batch.Execute(G.NewMessage().SetData("pune"))
48. Demo
49. Examples: Composition
50. Thank you! Piyush Verma @meson10 Oogway Consulting http://oogway.in