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?
   

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2. How much does your application
   weigh?
   

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3. Services
   

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4. Services
   

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5. Discovery
   ● Overlay Networks
   ● Registry/Reverse Proxying
   ● Port Scanning
   ● DNS
   

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6. Discovery:
   Overlay Networks
   ● Slow
   ● Rather call it host/container
   discovery?
   ● Probably use Docker - Swarm
   

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7. Discovery: Registry
   ● Etcd, consul, zookeeper
   ● Oh no, another cluster?
   

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8. ● How do you add dynamic hosts?
   ● Proxy could Crash?
   ● How to find Proxies?
   ● Connection Draining
   ● Latency+
   ● Gateway Partitioning
   Discovery:
   Reverse Proxies
   

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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.
   

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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
    

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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.
    

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12. Other Essentials
    ● Request Tracing
    ● Unified Logging
    ● Error Reporting
    ● Wildcard
    ● HTTP Multicast, Broadcast?
    

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13. Alternate?
    

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14. Sample Service
    

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15. HTTP Way
    

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16. PubSub/Redis
    

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17. PubSub Way
    

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18. Gilmour-Libs
    /gilmour-libs
    

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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()
    }
    

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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
    }
    

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21. Request Response
    CALLER SERVICE
    HELLO?
    ALOHA!
    WRONG NUMBER
    SENDER_ID
    CODE
    

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22. No/Good Service Discovery
    ● No querying discovery process
    ● Call service and not servers
    

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23. Load Balancing
    

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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
    

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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”}
    

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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
    

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27. And, How?
    

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28. Just this
    func bindListeners(g *G.Gilmour) {
    opts := G.NewHandlerOpts().SetGroup("exclusive")
    g.ReplyTo("echo", echoReply, opts)
    }
    

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29. Tracing, much?
    

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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"
    

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31. Network practices, much?
    

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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)
    

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33. Logging
    

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34. How?
    G.Logf("action.login %v", "message")
    G.Log("action.login")
    

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35. Errors
    

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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
    }
    

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37. Error Sample
    

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38. Asynchronous Architectures
    

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39. HTTP won’t, but
    ● Queues
    ● Celery
    ● SideKiq
    ● Kafka
    ● SQS
    ● Pravega
    ● Nats
    … Can
    

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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
    

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41. Logging,
    Revisited
    

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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)
    }
    

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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))
    }
    

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44. Composition
    

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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
    

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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)
    

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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"))
    

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48. Demo
    

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49. Examples: Composition
    

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50. Thank you!
    Piyush Verma
    @meson10
    Oogway
    Consulting
    http://oogway.in
    

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