VEVerilog · Beginners
Community homeHot discussions Latest posts Best of Knowledge base Resources About

Verilog · Beginners · Ten verilog-newbie anti-patterns — how many are you guilty of?

46
VEr/verilog-newbie·posted by winter·32 minutes agoJobs

Ten verilog-newbie anti-patterns — how many are you guilty of?

Some background first. Our setup is verilog-newbie 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.

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.

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.

21 comments

21 comments

M
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.

492
Ttang_hao·3 minutes ago

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

456
KkiteOPMod·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.

371
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.

71
Llinlin·28 minutes 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.

26
Rran_bo·2 days ago

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

376
Cchen_devOP·2 hours agoedited

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

1
Sslow_query·5 hours ago

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

230
Llinlin·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.

53
Lli_ming·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.

156
Ttang_hao·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
RraseOPMod·yesterdayedited

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

284
Llinlin·2 days ago

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

8
Zzhou_yi·yesterday

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.

41
Sslow_queryMod·1 hour ago

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

37
Oops_wang·yesterday

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

4
Nnikic·12 minutes agoedited

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

24
Aalice_dev·5 hours 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.

166
Cchen_dev·12 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.

1
Hhuang_ke·2 hours ago

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

2
Wwinter·just now

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

1

This is the post detail page /en/c/verilog-newbie/post/p13. Posts and comments are generated deterministically from a seeded PRNG, so the same post always renders the same content and the link can be shared, reloaded and indexed. In production this page reads MySQL for the post, Redis for hot-post caching, and fetches the whole comment tree in a single query on the path column.

See the database schema →