`cloud.google.com/go/pubsub` internal

talked on https://golangtokyo.connpass.com/event/129067/

Transcript

1. ©2019 Wantedly, Inc.
   `cloud.google.com/go/pubsub` internal
   golang.tokyo #24
   May 20, 2019 - Masayuki Izumi
   

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2. ©2019 Wantedly, Inc.
   $ whoami
   @izumin5210
   Wantedly, Inc.
   ‣ Wantedly People
   - Application Engineer (Go, Ruby, Web
   Frontend)
   ‣ Interested in…
   - Microservices
   - Developer Productivity
   - Developer Experience
   

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3. ©2019 Wantedly, Inc.
   Talk abst and desc
   

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4. ©2019 Wantedly, Inc.
   HPPHMFDMPVEHPͱఆٛݩ΁ͷδϟϯϓ͕࢖͑Δ؀ڥ
   ͕͋ΔͱɺൃදΛΑΓָ͓͠Έ͍͚ͨͩ·͢
   git clone https://github.com/googleapis/google-cloud-go.git
   cd google-cloud-go
   git checkout v0.39.0
   export GO111MODULE=on
   go mod download
   

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5. ©2019 Wantedly, Inc.
   1VC4VCɾϝοηʔδΩϡʔΈ͍ͨͳ΍ͭ
   ͔ͭͬͨ͜ͱ͋Δͻͱʔ
   

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6. ©2019 Wantedly, Inc.
   Pub/Sub
   • ඇಉظϝοηʔδϯάύϥμΠϜͷҰछ
   • ϝοηʔδૹ৴ऀ͕ड৴ऀΛ૝ఆͤͣʹ

   ϝοηʔδΛૹΕΔΑ͏ϓϩάϥϜ͞Εͨ΋ͷ

   

   

   

   

   

   Go
   Publisher

   ʢProducerʣ
   Ruby
   Python
   Go
   Go
   Subscriber

   ʢConsumerʣ
   Pub/Sub

   ʢBrokerʣ
   @hlts2, "Subee: Pub/Sub Worker Framework Implementation", GoCon 2019 Spring
   IUUQTTQFBLFSEFDLDPNIMUTTVCXPSLFSGSBNFXPSLJNQMFNFOUBUJPO
   

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7. ©2019 Wantedly, Inc.
   @hlts2, "Subee: Pub/Sub Worker Framework Implementation", GoCon 2019 Spring
   IUUQTTQFBLFSEFDLDPNIMUTTVCXPSLFSGSBNFXPSLJNQMFNFOUBUJPO
   ϢʔεέʔεʢඇಉظAPIʣ
   API Server Push Server
   Push ґཔ × 100ສ
   HTTP or gRPC
   ϢʔεέʔεʢඇಉظAPIʣ
   API Server Push Server
   Pub/Sub
   ࣗ෼ͷϖʔεͰॲཧ
   Push ґཔ × 100ສ
   "1*αʔό͕ϖʔεΛѲΔͷͰɺ
   8PSLFSଆ͕ϫʔΫϩʔυʹ଱͖͑Εͳ͍
   8PSLFS͸ࣗ෼ͷϖʔεͰॲཧΛ͢ΔͷͰམͪͳ͍͠ɺ
   ඇಉظͳͷͰ"1*αʔόʹ΋Өڹ͕ग़ͳ͍
   

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8. ©2019 Wantedly, Inc.
   ϢʔεέʔεʢΠϕϯτ఻ൖʣ
   User Service
   A Service
   Pub/Sub
   B Service
   C Service
   ProfileΛߋ৽
   υϝΠϯڥք͕Ͱ͖Δ
   ϢʔεέʔεʢΠϕϯτ఻ൖʣ
   User Service
   A Service
   B Service
   C Service
   ProfileΛߋ৽
   HTTP or gRPC
   @hlts2, "Subee: Pub/Sub Worker Framework Implementation", GoCon 2019 Spring
   IUUQTTQFBLFSEFDLDPNIMUTTVCXPSLFSGSBNFXPSLJNQMFNFOUBUJPO
   ج൫αʔϏε͕຤୺ͷϚΠΫϩαʔϏεʹ

   ґଘ͞Ε͍ͯΔ͜ͱΛ஌Βͳ͍ͱ͍͚ͳ͍
   ຤୺ͷαʔϏε͸ࣗ෼͕୭ʹґଘ͍ͯ͠Δ͔Λ஌͍ͬͯΔ͕ɺ
   ج൫αʔϏε͸୭ʹґଘ͞Ε͍ͯΔ͔Λ஌Βͳͯ͘ࡁΉ
   

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9. ©2019 Wantedly, Inc.
   client, err := pubsub.NewClient(ctx, "project-id")
   if err != nil {
   // ...
   }
   defer client.Close()
   // topic リソースは事前につくっておく
   topic := client.Topic("my-topic")
   defer topic.Stop()
   topic.Publish(ctx, &pubsub.Message{
   Data: string("Hello, Workd!"),
   })
   IUUQTDMPVEHPPHMFDPNQVCTVCEPDTPWFSWJFX
   

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10. ©2019 Wantedly, Inc. IUUQTDMPVEHPPHMFDPNQVCTVCEPDTPWFSWJFX
    client, err := pubsub.NewClient(ctx, "project-id")
    if err != nil {
    // ...
    }
    defer client.Close()
    // subscription リソースは事前につくっておく
    subscription := client.Subscription("my-subscription")
    subscription.Receive(ctx, func(ctx context.Context, msg *pubsub.Message) error {
    // ...
    return nil
    })
    

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11. ©2019 Wantedly, Inc.
    "1*ɾ࢖͍ํ͸௒γϯϓϧ
    Ͱ΋಺෦Ͱ͸͔ͳΓ͍Ζ͍Ζ΍͍ͬͯΔ
    

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12. ©2019 Wantedly, Inc.
    ৴པੑͱύϑΥʔϚϯε͕ཁٻ͞ΕΔ
    ϛυϧ΢ΣΞͷΫϥΠΞϯτ
    

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13. ©2019 Wantedly, Inc.
    ͦͷ಺෦Λ࣮ࡍʹݟͯΈ·͠ΐ͏
    ϥΠϒίʔυϦʔσΟϯά͢Δͧʂʂ
    

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14. ©2019 Wantedly, Inc.
    Publishing
    

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15. ©2019 Wantedly, Inc.
    entrypoint:
    `func (*pubsub.Topic) Publish(context.Context, *pubsub.Message)`
    QVCTVCUPQJDHP-
    1VCMJTIJOH FOUSZQPJOU
    

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16. ©2019 Wantedly, Inc.
    google.golang.org/api/support/bundler
    func NewBundler(itemExample interface{}, handler func(interface{})) *Bundler
    func (b *Bundler) Add(item interface{}, size int) error
    func (b *Bundler) AddWait(ctx context.Context, item interface{}, size int) error
    func (b *Bundler) Flush()
    1VCMJTIJOH CVOEMFS
    ΞΠςϜΛཷΊࠐΜͰɺմ͝ͱʹॲཧ͢Δ
    ʢσʔλ਺ σʔλ༰ྔ ࣌ؒͳͲͰGMVTI͢Δ৚݅ΛܾΊΒΕΔʣ
    

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17. ©2019 Wantedly, Inc.
    google.golang.org/api/support/bundler
    t.bundler = bundler.NewBundler(&bundledMessage{}, func(items interface{}) {
    // TODO(jba): use a context detached from the one passed to NewClient.
    ctx := context.TODO()
    if timeout != 0 {
    var cancel func()
    ctx, cancel = context.WithTimeout(ctx, timeout)
    defer cancel()
    }
    t.publishMessageBundle(ctx, items.([]*bundledMessage))
    })
    1VCMJTIJOH CVOEMFS
    (PPHMF$MPVE1VC4VCͷQVCMJTIFS͸ɺCVOEMFSʹཷΊࠐΜͰඇಉظʹϝοηʔδΛૹ৴͍ͯ͠Δ
    ./pubsub/topic.go L412
    

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18. ©2019 Wantedly, Inc.
    github.com/googleapis/gax-go
    gax.WithRetry(func() gax.Retryer {
    return gax.OnCodes([]codes.Code{
    codes.Aborted,
    codes.Canceled,
    codes.Internal,
    codes.ResourceExhausted,
    codes.Unavailable,
    codes.Unknown,
    }, gax.Backoff{
    Initial: 100 * time.Millisecond,
    Max: 60000 * time.Millisecond,
    Multiplier: 1.3,
    })
    }),
    },
    1VCMJTIJOH HJUIVCDPNHPPHMFBQJTHBYHP
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    QVCTVCBQJWQVCMJTIFIS@DMJFOUHP-
    

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19. ©2019 Wantedly, Inc.
    Subscribing
    

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20. ©2019 Wantedly, Inc.
    entrypoint:
    `func (*pubsub.Subscription) Receive(context.Context, func(context.Context, *pubsub.Message)) error`
    QVCTVCTVCTDSJQUJPOHP-
    4VCTDSJCJOH FOUSZQPJOU
    

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21. ©2019 Wantedly, Inc.
    golang.org/x/sync/errgroup
    group, gctx := errgroup.WithContext(ctx)
    for i := 0; i < numGoroutines; i++ {
    group.Go(func() error {
    return s.receive(gctx, po, fc, f)
    })
    }
    return group.Wait()
    1VCMJTIJOH FSSHSPVQ
    AFSSHSPVQAΛར༻͠ɺϝοηʔδΛड৴͢ΔͨΊͷXPSLFSHPSPVUJOFΛੜΈग़͍ͯ͠Δ
    ./pubsub/subscription.go L547
    

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22. ©2019 Wantedly, Inc.
    4VCTDSJCJOH "DL/BDL
    A QVCTVC.FTTBHF
    "DL
    A͕ݺ͹ΕΔͱ
    "DL଴ͪϝοηʔδͷεϥΠεʹBQQFOEͨ͋͠ͱɺ
    GMPXDPOUSPMMFSʹͦΕΛ஌ΒͤͯΩϡʔʹۭ͖Λ࡞Δ
    msg.doneFunc = func(ackID string, ack bool, receiveTime time.Time) {
    defer fc.release(msgLen)
    old(ackID, ack, receiveTime)
    }
    func (m *Message) Ack() {
    m.done(true)
    }
    func (m *Message) Nack() {
    m.done(false)
    }
    func (m *Message) done(ack bool) {
    if m.calledDone {
    return
    }
    m.calledDone = true
    m.doneFunc(m.ackID, ack, m.receiveTime)
    }
    func (it *messageIterator) done(ackID string, ack bool, receiveTime time.Time) {
    it.ackTimeDist.Record(int(time.Since(receiveTime) / time.Second))
    it.mu.Lock()
    defer it.mu.Unlock()
    delete(it.keepAliveDeadlines, ackID)
    if ack {
    it.pendingAcks[ackID] = true
    } else {
    it.pendingNacks[ackID] = true
    }
    it.checkDrained()
    }
    QVCTVCJUFSBUPSHP-
    QVCTVCTVCTDSJQUJPOHP-
    QVCTVCNFTTBHFHP-
    

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23. ©2019 Wantedly, Inc.
    ʜΈ͍ͨͳײ͡ͷ͜ͱΛɺࣾ಺ษڧձͰ΍ͬͯ·͢
    .JDSPTFSWJDFT.POEBZIUUQTXXXXBOUFEMZDPNQSPKFDUT
    (PQIFST$PEF3FBEJOH1BSUZΠϕϯτϖʔδ͕ͳ͍ͷͰ੠͔͚͍ͯͩ͘͞
    

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