Open Source · Blog · Hiring: remote open-source-blog engineer (full-time, long-term)

134
OSr/open-source-blog·posted by li_ming·just nowTutorial

Hiring: remote open-source-blog engineer (full-time, long-term)

Some background first. Our setup is open-source-blog plus three downstream services, seven figures of daily requests, peaking around nine in the evening.

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.

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71 comments

71 comments

M
Mmike_xu·2 days ago

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

504
Nnikic·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.

481
Nnikic·2 days ago

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

461
Nnikic·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.

455
Ddev_zhou·12 minutes agoedited

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

138
Hhuang_ke·just now

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.

366
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.

331
Bbob_chen·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.

336
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.

43
Oops_wangOP·yesterday

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.

225
Nnikic·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.

88
Cchen_devOP·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.

84
Zzhu_zong·2 days ago

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

202
Nnikic·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.

159
Rran_boOPMod·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.

138
Kkite·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.

137
Ddev_zhou·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.

124
Kkernel_panic·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.

102
Nnikic·just now

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

95
Rrase·3 minutes ago

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

92
Sslow_query·5 hours ago

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

76
Ttang_hao·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.

29
Zzhu_zongOP·2 days ago

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

14
Sswoole_leeOP·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.

290
Mmike_xu·2 hours ago

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

60
Nnikic·5 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.

21
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.

2
Kkernel_panic·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.

16
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.

12
Zzhu_zong·3 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.

11
WwinterOP·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.

473
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.

423
Mmike_xu·1 hour ago

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

287
Aalice_dev·12 minutes ago

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

357
Rrase·2 days ago

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

300
Ddev_zhou·2 days agoedited

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

169
Kkernel_panic·5 hours ago

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

257
Rrase·just now

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

75
Nnikic·2 days ago

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

2
Hhuang_ke·2 days ago

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

51
Sslow_queryMod·3 minutes ago

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

16
Kkernel_panic·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.

463
Kkite·yesterdayLevel 6

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

1
Wwinter·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.

386
Lli_ming·5 hours ago

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

119
Hhuang_keOP·2 days agoLevel 6

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

314
Rran_bo·2 days agoLevel 6

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.

30
Mmike_xu·just now

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

13
Sslow_query·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.

345
Lli_mingOP·2 days ago

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

1
Aalice_dev·2 days agoLevel 6

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

125
Llinlin·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.

1
Kkernel_panic·2 days ago

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

3
Aalice_dev·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.

1
Llinlin·12 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.

446
Sswoole_lee·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.

158
Zzhu_zong·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.

345
Rran_bo·2 days ago

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

180
Cchen_dev·2 days agoedited

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

58
Ddev_zhou·2 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.

47
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.

3
Nnikic·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.

6
Ddev_zhou·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.

5
Nnikic·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.

2
Bbob_chen·2 days ago

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

18
Hhuang_keMod·1 hour ago

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

1
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.

1
Kkite·2 days ago

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

3
Zzhu_zong·2 days ago

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

366
Kkernel_panicMod·3 minutes ago

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

72
Ttang_hao·2 days ago

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

33

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