Baking · Events · Built a visual debugging panel for baking-events over the weekend

214
BAr/baking-events·posted by slow_query·3 days agoJobs

Built a visual debugging panel for baking-events over the weekend

Most baking-events articles stop at "how to use it" and never cover "when not to use it". This is an attempt at the second half.

One last trap: in container environments remember to adjust the memory-related parameters in step. Otherwise the host limit and the process expectation disagree, and the symptom is intermittent, unreproducible failure.

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67 comments

67 comments

M
Ddev_zhouOP·2 days agoedited

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

515
Hhuang_ke·2 days ago

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

504
Bbob_chen·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.

460
Mmike_xu·5 hours ago

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

430
Lli_ming·28 minutes ago

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

404
Kkernel_panic·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.

231
Lli_ming·yesterday

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.

54
Zzhou_yi·2 days ago

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

313
Mmike_xu·2 days ago

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

306
Rran_bo·2 days ago

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

288
Nnikic·2 days ago

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

267
Ttang_haoOP·5 hours ago

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

33
Nnikic·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.

507
Wwinter·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.

1
Mmike_xuOP·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.

177
Sslow_query·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.

168
Hhuang_ke·1 hour agoedited

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

66
Zzhou_yi·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.

379
Cchen_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.

289
Sswoole_lee·2 days ago

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

55
Hhuang_keMod·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.

25
Aalice_dev·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.

165
Aalice_devOP·2 days ago

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

352
Bbob_chen·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.

31
Zzhu_zong·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.

1
Rrase·5 hours ago

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

6
Hhuang_keOP·28 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.

196
Cchen_dev·1 hour ago

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

327
Kkernel_panic·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.

361
Rran_bo·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.

124
Rran_bo·2 days ago

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

174
Kkernel_panic·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.

210
Zzhou_yi·12 minutes 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.

167
Zzhu_zong·2 days ago

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

44
Rrase·2 days ago

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

167
RraseOP·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.

22
Sswoole_lee·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.

115
Ddev_zhou·2 hours ago

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

126
Ddev_zhou·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.

159
Nnikic·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.

155
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.

92
Nnikic·2 days ago

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

44
Nnikic·28 minutes ago

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

130
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.

115
Hhuang_ke·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.

89
Nnikic·2 days ago

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

197
Zzhou_yi·2 hours 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.

77
Hhuang_keOP·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.

222
Hhuang_ke·3 minutes ago

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

152
Aalice_devOP·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.

332
Kkite·just now

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

91
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.

157
Bbob_chenOP·12 minutes ago

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

11
Oops_wang·2 days ago

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

64
Ttang_hao·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.

395
Cchen_dev·1 hour 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.

16
Rrase·2 days ago

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

11
Bbob_chen·2 days ago

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

10
Sslow_query·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
Kkite·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.

327
Zzhu_zong·3 minutes agoedited

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

1
Zzhu_zong·yesterday

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.

273
RraseOP·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.

190
Rrase·2 days ago

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

390
Ddev_zhou·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.

37
Kkite·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.

12
Cchen_dev·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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