Jupyter · Advanced · Hiring: remote jupyter-pro engineer (full-time, long-term)

652
JUr/jupyter-pro·posted by huang_ke·32 minutes agoAnnouncement

Hiring: remote jupyter-pro engineer (full-time, long-term)

Short version: jupyter-pro needs almost no tuning at small and medium scale — the point where it starts to hurt is much further out than most people assume. Full measurements below.

Worth noting: the official docs do cover this, just in a very inconspicuous spot. I only found it reading the source comments, where the author explains the reasoning — roughly "so that it degrades into predictable behaviour in extreme cases".

// Minimal reproduction: you must use a real long-tail distribution here.
// Uniform load-test traffic will never trigger this.
func (s *Server) handle(ctx context.Context) error {
    conn, err := s.pool.Acquire(ctx)
    if err != nil {
        return fmt.Errorf("acquire: %w", err)
    }
    defer conn.Release()

    return s.do(ctx, conn)
}

The first thing was to collapse the variables. We were changing config and upgrading the version at the same time, and afterwards nobody could say which change caused what. We rolled back to moving one variable at a time, re-ran three times, and only then did the curve settle. Tedious, but not skippable.

We also fixed monitoring along the way: replaced average-based alerts with percentiles and split them per endpoint. False alerts dropped by about seventy percent and the on-call rotation visibly cheered up.

On trade-offs, my view is this: if nobody on the team owns this area long-term, do not introduce a second mechanism. With two coexistence you first have to work out which one is even in play when things break, and that costs far more than the performance you saved.

390 comments

390 comments

· first 120 loaded
M
Mmike_xu·just now

There is actually a simpler fix that needs no architecture change: move this check up to the gateway and the problem disappears. The cost is one extra lookup at the gateway.

495
Sslow_query·2 days ago

Sharing our numbers, 8 cores 16GB, same scenario:

| Concurrency | P50 | P99 |
|---|---|---|
| 200 | 12ms | 88ms |
| 500 | 31ms | 340ms |

P99 clearly collapses at 500 concurrency, which lines up with your knee point.

488
Cchen_dev·12 minutes ago

Has anyone run a controlled experiment? I did, reducing it to a single variable, and the difference was 4% — within noise. So I suspect the main cause is something else.

467
Sswoole_lee·2 days ago

Saved. I am reworking this area this week — this saves a lot of wrong turns.

452
Bbob_chenOP·2 days ago

This matches what we see in production. We only hit it past 3k QPS; the earlier load tests showed nothing — the test traffic was too clean, with no long-tail requests.

382
Bbob_chen·2 days ago

Sharing our numbers, 8 cores 16GB, same scenario:

| Concurrency | P50 | P99 |
|---|---|---|
| 200 | 12ms | 88ms |
| 500 | 31ms | 340ms |

P99 clearly collapses at 500 concurrency, which lines up with your knee point.

2
Wwinter·2 days ago

One counter-example: below jupyter-pro 7.4 the semantics of that code are different, so do not copy it verbatim. We got burned in staging and rolled back once.

22
Ttang_hao·12 minutes ago

We have run this in production for two years without hitting it. That said, we never reached this scale, so our experience is not really evidence here.

5
Lli_ming·2 days ago

One counter-example: below jupyter-pro 7.4 the semantics of that code are different, so do not copy it verbatim. We got burned in staging and rolled back once.

347
Ddev_zhouOP·2 days ago

A question: what changes in a container with a 512Mi memory limit? That is how we run it in production.

278
Ttang_haoMod·just now

I see point 3 differently. The trade-off depends on your read/write ratio: read-heavy with little writing means caching actually widens the inconsistency window.

16
Llinlin·2 days ago

This matches what we see in production. We only hit it past 3k QPS; the earlier load tests showed nothing — the test traffic was too clean, with no long-tail requests.

303
Rran_bo·2 days ago

Agreeing with the above. One addition: with this option enabled the GC count in your metrics doubles, so adjust the alert threshold at the same time or it will keep firing.

303
Rrase·2 days ago

Has anyone run a controlled experiment? I did, reducing it to a single variable, and the difference was 4% — within noise. So I suspect the main cause is something else.

281
Hhuang_keMod·2 days ago

One counter-example: below jupyter-pro 7.4 the semantics of that code are different, so do not copy it verbatim. We got burned in staging and rolled back once.

275
Sswoole_lee·just nowedited

I see point 3 differently. The trade-off depends on your read/write ratio: read-heavy with little writing means caching actually widens the inconsistency window.

271
Kkite·2 days ago

We have run this in production for two years without hitting it. That said, we never reached this scale, so our experience is not really evidence here.

265
Rrase·3 minutes ago

Saved. I am reworking this area this week — this saves a lot of wrong turns.

263
Llinlin·2 days agoedited

Can you give a minimal reproduction? I ran it locally for ten minutes and could not reproduce on macOS with the latest version.

251
Oops_wang·2 days ago

I just read the jupyter-pro source — the author actually explains the reasoning in a comment, roughly "so that it degrades into predictable behaviour in extreme cases".

112
Zzhou_yi·2 days ago

Worth learning from this debugging approach. We went straight at the logs and took a much longer route.

10
Aalice_dev·1 hour ago

I see point 3 differently. The trade-off depends on your read/write ratio: read-heavy with little writing means caching actually widens the inconsistency window.

239
Lli_ming·5 hours ago

I see point 3 differently. The trade-off depends on your read/write ratio: read-heavy with little writing means caching actually widens the inconsistency window.

51
Mmike_xu·2 hours ago

This is not a jupyter-pro problem, it is a usage problem. The docs say this API is not thread-safe and you must lock around it yourself.

235
Aalice_dev·2 days ago

I see point 3 differently. The trade-off depends on your read/write ratio: read-heavy with little writing means caching actually widens the inconsistency window.

178
Ddev_zhouOP·2 days ago

A question: what changes in a container with a 512Mi memory limit? That is how we run it in production.

117
Aalice_devMod·3 minutes ago

This matches what we see in production. We only hit it past 3k QPS; the earlier load tests showed nothing — the test traffic was too clean, with no long-tail requests.

170
Hhuang_ke·2 hours ago

A question: what changes in a container with a 512Mi memory limit? That is how we run it in production.

424
Cchen_devOPMod·3 minutes ago

Worth learning from this debugging approach. We went straight at the logs and took a much longer route.

324
Aalice_dev·2 days ago

Sharing our numbers, 8 cores 16GB, same scenario:

| Concurrency | P50 | P99 |
|---|---|---|
| 200 | 12ms | 88ms |
| 500 | 31ms | 340ms |

P99 clearly collapses at 500 concurrency, which lines up with your knee point.

315
Oops_wang·just now

Saved. I am reworking this area this week — this saves a lot of wrong turns.

210
Zzhou_yi·2 days ago

A question: what changes in a container with a 512Mi memory limit? That is how we run it in production.

338
Ddev_zhou·2 days agoedited

Sharing our numbers, 8 cores 16GB, same scenario:

| Concurrency | P50 | P99 |
|---|---|---|
| 200 | 12ms | 88ms |
| 500 | 31ms | 340ms |

P99 clearly collapses at 500 concurrency, which lines up with your knee point.

208
Lli_ming·2 days agoedited

I see point 3 differently. The trade-off depends on your read/write ratio: read-heavy with little writing means caching actually widens the inconsistency window.

1
Sswoole_lee·28 minutes ago

Can you give a minimal reproduction? I ran it locally for ten minutes and could not reproduce on macOS with the latest version.

59
Cchen_dev·2 days agoedited

There is actually a simpler fix that needs no architecture change: move this check up to the gateway and the problem disappears. The cost is one extra lookup at the gateway.

6
Rran_bo·2 days ago

Can you give a minimal reproduction? I ran it locally for ten minutes and could not reproduce on macOS with the latest version.

129
Zzhu_zong·2 days ago

Can you give a minimal reproduction? I ran it locally for ten minutes and could not reproduce on macOS with the latest version.

165
Sswoole_lee·just nowedited

This is not a jupyter-pro problem, it is a usage problem. The docs say this API is not thread-safe and you must lock around it yourself.

151
Hhuang_ke·2 days ago

Saved. I am reworking this area this week — this saves a lot of wrong turns.

143
Sswoole_lee·2 days ago

Can you give a minimal reproduction? I ran it locally for ten minutes and could not reproduce on macOS with the latest version.

96
Hhuang_ke·2 days ago

There is actually a simpler fix that needs no architecture change: move this check up to the gateway and the problem disappears. The cost is one extra lookup at the gateway.

151
Oops_wang·2 days ago

We have run this in production for two years without hitting it. That said, we never reached this scale, so our experience is not really evidence here.

483
Ddev_zhouMod·2 days ago

I just read the jupyter-pro source — the author actually explains the reasoning in a comment, roughly "so that it degrades into predictable behaviour in extreme cases".

151
Bbob_chenMod·2 days ago

Has anyone run a controlled experiment? I did, reducing it to a single variable, and the difference was 4% — within noise. So I suspect the main cause is something else.

131
Nnikic·2 days ago

One counter-example: below jupyter-pro 7.4 the semantics of that code are different, so do not copy it verbatim. We got burned in staging and rolled back once.

294
Aalice_dev·2 days ago

This is not a jupyter-pro problem, it is a usage problem. The docs say this API is not thread-safe and you must lock around it yourself.

130
Mmike_xu·1 hour ago

We have run this in production for two years without hitting it. That said, we never reached this scale, so our experience is not really evidence here.

2
Aalice_devOP·12 minutes ago

Worth learning from this debugging approach. We went straight at the logs and took a much longer route.

60
Kkite·12 minutes ago

Thanks for sharing real numbers — far more useful than the articles that only cover concepts.

258
Kkernel_panic·12 minutes ago

Can you give a minimal reproduction? I ran it locally for ten minutes and could not reproduce on macOS with the latest version.

265
Nnikic·2 hours ago

Has anyone run a controlled experiment? I did, reducing it to a single variable, and the difference was 4% — within noise. So I suspect the main cause is something else.

249
WwinterOP·2 days agoedited

Thanks for sharing real numbers — far more useful than the articles that only cover concepts.

218
Kkite·12 minutes ago

Thanks for sharing real numbers — far more useful than the articles that only cover concepts.

17
Ddev_zhou·2 days agoedited

Agreeing with the above. One addition: with this option enabled the GC count in your metrics doubles, so adjust the alert threshold at the same time or it will keep firing.

71
Rran_boOP·2 days agoLevel 6

A question: what changes in a container with a 512Mi memory limit? That is how we run it in production.

474
Bbob_chen·2 days ago

We have run this in production for two years without hitting it. That said, we never reached this scale, so our experience is not really evidence here.

61
Rrase·2 days agoLevel 6

I just read the jupyter-pro source — the author actually explains the reasoning in a comment, roughly "so that it degrades into predictable behaviour in extreme cases".

509
Cchen_dev·2 days agoLevel 6

Saved. I am reworking this area this week — this saves a lot of wrong turns.

300
Zzhou_yi·2 days agoLevel 6

I just read the jupyter-pro source — the author actually explains the reasoning in a comment, roughly "so that it degrades into predictable behaviour in extreme cases".

21
Lli_ming·2 days ago

We have run this in production for two years without hitting it. That said, we never reached this scale, so our experience is not really evidence here.

53
Lli_ming·2 days agoLevel 6

This is not a jupyter-pro problem, it is a usage problem. The docs say this API is not thread-safe and you must lock around it yourself.

89
RraseMod·3 minutes ago

Sharing our numbers, 8 cores 16GB, same scenario:

| Concurrency | P50 | P99 |
|---|---|---|
| 200 | 12ms | 88ms |
| 500 | 31ms | 340ms |

P99 clearly collapses at 500 concurrency, which lines up with your knee point.

35
Lli_ming·2 days agoLevel 6

This matches what we see in production. We only hit it past 3k QPS; the earlier load tests showed nothing — the test traffic was too clean, with no long-tail requests.

1
Nnikic·5 hours ago

I just read the jupyter-pro source — the author actually explains the reasoning in a comment, roughly "so that it degrades into predictable behaviour in extreme cases".

191
Zzhou_yi·2 days ago

Saved. I am reworking this area this week — this saves a lot of wrong turns.

471
Mmike_xu·2 days ago

Has anyone run a controlled experiment? I did, reducing it to a single variable, and the difference was 4% — within noise. So I suspect the main cause is something else.

329
Lli_ming·5 hours ago

This matches what we see in production. We only hit it past 3k QPS; the earlier load tests showed nothing — the test traffic was too clean, with no long-tail requests.

175
Hhuang_keOP·2 days ago

A question: what changes in a container with a 512Mi memory limit? That is how we run it in production.

98
Sslow_queryOP·3 minutes ago

One counter-example: below jupyter-pro 7.4 the semantics of that code are different, so do not copy it verbatim. We got burned in staging and rolled back once.

76
Kkernel_panic·just now

Sharing our numbers, 8 cores 16GB, same scenario:

| Concurrency | P50 | P99 |
|---|---|---|
| 200 | 12ms | 88ms |
| 500 | 31ms | 340ms |

P99 clearly collapses at 500 concurrency, which lines up with your knee point.

25
Sslow_queryMod·2 days ago

This is not a jupyter-pro problem, it is a usage problem. The docs say this API is not thread-safe and you must lock around it yourself.

30
Bbob_chen·yesterday

This matches what we see in production. We only hit it past 3k QPS; the earlier load tests showed nothing — the test traffic was too clean, with no long-tail requests.

1
Kkernel_panic·just now

Has anyone run a controlled experiment? I did, reducing it to a single variable, and the difference was 4% — within noise. So I suspect the main cause is something else.

353
Mmike_xu·2 days agoLevel 6

I see point 3 differently. The trade-off depends on your read/write ratio: read-heavy with little writing means caching actually widens the inconsistency window.

2
Wwinter·2 days agoedited

Sharing our numbers, 8 cores 16GB, same scenario:

| Concurrency | P50 | P99 |
|---|---|---|
| 200 | 12ms | 88ms |
| 500 | 31ms | 340ms |

P99 clearly collapses at 500 concurrency, which lines up with your knee point.

141
Nnikic·2 days ago

This matches what we see in production. We only hit it past 3k QPS; the earlier load tests showed nothing — the test traffic was too clean, with no long-tail requests.

1
Ddev_zhouOP·2 days agoLevel 6

Worth learning from this debugging approach. We went straight at the logs and took a much longer route.

3
Mmike_xu·12 minutes ago

One counter-example: below jupyter-pro 7.4 the semantics of that code are different, so do not copy it verbatim. We got burned in staging and rolled back once.

64
Rran_bo·2 days ago

Worth learning from this debugging approach. We went straight at the logs and took a much longer route.

41
Bbob_chen·28 minutes ago

Agreeing with the above. One addition: with this option enabled the GC count in your metrics doubles, so adjust the alert threshold at the same time or it will keep firing.

274
Sslow_query·2 days ago

Thanks for sharing real numbers — far more useful than the articles that only cover concepts.

120
Kkite·1 hour ago

Agreeing with the above. One addition: with this option enabled the GC count in your metrics doubles, so adjust the alert threshold at the same time or it will keep firing.

109
Wwinter·2 days ago

One counter-example: below jupyter-pro 7.4 the semantics of that code are different, so do not copy it verbatim. We got burned in staging and rolled back once.

108
Ttang_hao·2 days ago

I just read the jupyter-pro source — the author actually explains the reasoning in a comment, roughly "so that it degrades into predictable behaviour in extreme cases".

102
Rran_bo·2 days ago

There is actually a simpler fix that needs no architecture change: move this check up to the gateway and the problem disappears. The cost is one extra lookup at the gateway.

81
Nnikic·2 days ago

There is actually a simpler fix that needs no architecture change: move this check up to the gateway and the problem disappears. The cost is one extra lookup at the gateway.

249
Zzhu_zong·2 days ago

Agreeing with the above. One addition: with this option enabled the GC count in your metrics doubles, so adjust the alert threshold at the same time or it will keep firing.

16
Zzhu_zong·3 minutes ago

Can you give a minimal reproduction? I ran it locally for ten minutes and could not reproduce on macOS with the latest version.

100
Cchen_dev·12 minutes ago

Thanks for sharing real numbers — far more useful than the articles that only cover concepts.

47
Sswoole_lee·just now

Saved. I am reworking this area this week — this saves a lot of wrong turns.

248
Sslow_query·2 days ago

Can you give a minimal reproduction? I ran it locally for ten minutes and could not reproduce on macOS with the latest version.

94
Ddev_zhou·2 days ago

This is not a jupyter-pro problem, it is a usage problem. The docs say this API is not thread-safe and you must lock around it yourself.

90
Zzhou_yi·2 days ago

A question: what changes in a container with a 512Mi memory limit? That is how we run it in production.

88
NnikicOP·just nowedited

Has anyone run a controlled experiment? I did, reducing it to a single variable, and the difference was 4% — within noise. So I suspect the main cause is something else.

18
Wwinter·2 days ago

We have run this in production for two years without hitting it. That said, we never reached this scale, so our experience is not really evidence here.

70
Llinlin·2 days agoedited

Has anyone run a controlled experiment? I did, reducing it to a single variable, and the difference was 4% — within noise. So I suspect the main cause is something else.

61
Nnikic·2 days ago

I just read the jupyter-pro source — the author actually explains the reasoning in a comment, roughly "so that it degrades into predictable behaviour in extreme cases".

42
Aalice_dev·2 days ago

I see point 3 differently. The trade-off depends on your read/write ratio: read-heavy with little writing means caching actually widens the inconsistency window.

33
Aalice_dev·2 days ago

Agreeing with the above. One addition: with this option enabled the GC count in your metrics doubles, so adjust the alert threshold at the same time or it will keep firing.

159
Ddev_zhou·2 days ago

This is not a jupyter-pro problem, it is a usage problem. The docs say this API is not thread-safe and you must lock around it yourself.

33
Wwinter·5 hours ago

There is actually a simpler fix that needs no architecture change: move this check up to the gateway and the problem disappears. The cost is one extra lookup at the gateway.

26
Nnikic·2 days ago

This is not a jupyter-pro problem, it is a usage problem. The docs say this API is not thread-safe and you must lock around it yourself.

57
Aalice_dev·2 days ago

Saved. I am reworking this area this week — this saves a lot of wrong turns.

17
Bbob_chen·2 days ago

Thanks for sharing real numbers — far more useful than the articles that only cover concepts.

11
Kkite·just now

Agreeing with the above. One addition: with this option enabled the GC count in your metrics doubles, so adjust the alert threshold at the same time or it will keep firing.

9
Oops_wang·12 minutes ago

Worth learning from this debugging approach. We went straight at the logs and took a much longer route.

329
Llinlin·2 days ago

Agreeing with the above. One addition: with this option enabled the GC count in your metrics doubles, so adjust the alert threshold at the same time or it will keep firing.

402
Hhuang_ke·2 days ago

I just read the jupyter-pro source — the author actually explains the reasoning in a comment, roughly "so that it degrades into predictable behaviour in extreme cases".

151
Oops_wang·2 days ago

Worth learning from this debugging approach. We went straight at the logs and took a much longer route.

13
Rran_bo·2 days ago

Worth learning from this debugging approach. We went straight at the logs and took a much longer route.

7
Zzhu_zong·just now

We have run this in production for two years without hitting it. That said, we never reached this scale, so our experience is not really evidence here.

6
Oops_wang·2 days ago

One counter-example: below jupyter-pro 7.4 the semantics of that code are different, so do not copy it verbatim. We got burned in staging and rolled back once.

4
Oops_wang·2 days ago

Thanks for sharing real numbers — far more useful than the articles that only cover concepts.

165
Cchen_dev·3 minutes ago

There is actually a simpler fix that needs no architecture change: move this check up to the gateway and the problem disappears. The cost is one extra lookup at the gateway.

362
WwinterMod·2 days ago

There is actually a simpler fix that needs no architecture change: move this check up to the gateway and the problem disappears. The cost is one extra lookup at the gateway.

4
Sslow_queryOP·2 days ago

Thanks for sharing real numbers — far more useful than the articles that only cover concepts.

94
Oops_wangMod·2 days ago

This matches what we see in production. We only hit it past 3k QPS; the earlier load tests showed nothing — the test traffic was too clean, with no long-tail requests.

129
Zzhu_zong·2 days ago

Sharing our numbers, 8 cores 16GB, same scenario:

| Concurrency | P50 | P99 |
|---|---|---|
| 200 | 12ms | 88ms |
| 500 | 31ms | 340ms |

P99 clearly collapses at 500 concurrency, which lines up with your knee point.

1
Ddev_zhou·2 days ago

A question: what changes in a container with a 512Mi memory limit? That is how we run it in production.

1

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