[cannot reproduce] Pagination cuts off logs

[ackava]

🔍 Check for existing issues

• Completed

How is Dozzle deployed?

Standalone Deployment

📦 Dozzle version

v8.14.9

✅ Command used to run Dozzle

agent

🐛 Describe the bug / provide steps to reproduce it

Some logs are missing while seeing logs, I have attached screenshots

💻 Environment

Ubuntu 24 with latest Docker

📜 Dozzle logs are required for debugging purposes. You may need to enable debug mode. See https://dozzle.dev/guide/debugging.

I am seeing this one entry in dozzle-ui, but I dont' know if it is relevant.

{"level":"error","version":"v8.14.9","error":"unknown code: Unavailable with rpc error: code = Unavailable desc = error reading from server: EOF","container":"f1d111ede996","time":"2025-11-27T04:41:06Z","message":"unknown error while streaming logs"}

The container id is not same as the one where logs are missing, and there aren't any other error or warning items on dozzle-agent or dozzle-ui for every host.

📸 If applicable, add screenshots to help explain your bug

You can find actual logs after the same line in console

[ackava]

I think I found the issue, I keep on scrolling up and it looks like in slow speed, logs take time to download, so partial log is displayed if new log fetch request is sent before previous fetch completes.

After clearing cache, I scroll up slowly (letting previous request complete), then I don't see missing lines.

[amir20]

Hmm that's weird and possible a bug. Can you record a video with web tools open so I can see what's happening?

[ackava]

This is the log in the chrome debugger tools network pane,

This is when logs load.

This is when I scroll up.

This is when I scroll up again.

Do you see the gap in the time "from" and "to" from previous request?
First request starts from 9.18 but second request's from doesn't end at 9.18.

[amir20]

I think I know what might be happening. The screenshot still make me wonder if it's a bug though.

My hunch is that you have logs all coming together so their timestamp is identical. Dozzle uses Docker API and it doesn't really have a clean API to fetch between two logs. I have to use timestamp instead. In your screenshot all logs are printed at the same time so when Dozzle tries to paginate it doesn't know where to cut off.

Now, the screenshots, I do wonder if there is a bug. 🤔 You said when you did it slow it wasn't happening though. So I wanted to see a video of that. Do you mean scrollup slow or waiting for each to load.

Did you scroll up and then very fast scroll up again? What's the best way to reproduce this for myself?

1. Does this happen to other logs too that are more spread? Or is it just this container?
2. What do you mean by slow?
3. Do you think if I print logs very close to each other would be a good way to reproduce?

[ackava]

1. Logs are missing from every container, in fact, many times we noticed that some logs are missing and we assumed that we have bug in our code and we went on whole week trying to figure out the bug, but when I compared to every other container, logs are missing.
2. It appears that logs are skipped when I scroll up, speed of scrolling up doesn't usually matter. But yes there are gaps.
3. Docker displays logs by UTC timestamp so, I think looking up history should have closest 1ms gap since the oldest timestamp received from the previous log fetch. I checked docker api and I feel this is the only solution.

[amir20]

Thanks. Any details you have helps. I am going to print 1000 lines of logs at the same time and see if it breaks. No one else has reported this so something feels unique.

[amir20]

Docker displays logs by UTC timestamp so, I think looking up history should have closest 1ms gap since the oldest timestamp received from the previous log fetch. I checked docker api and I feel this is the only solution.

I actually use nanoseconds.

So here is what I did:

1. I created a VM so that I can test with agent since that's what you are all doing.
2. I created a random container that prints 1000 lines at the same time.

docker logs ...
2025-11-29T17:20:35.362231521Z line 9981
2025-11-29T17:20:35.362232271Z line 9982
2025-11-29T17:20:35.362233021Z line 9983
2025-11-29T17:20:35.362233771Z line 9984
2025-11-29T17:20:35.362234521Z line 9985
2025-11-29T17:20:35.362235271Z line 9986
2025-11-29T17:20:35.362236021Z line 9987
2025-11-29T17:20:35.362236771Z line 9988
2025-11-29T17:20:35.362237521Z line 9989
2025-11-29T17:20:35.362238229Z line 9990
2025-11-29T17:20:35.362238979Z line 9991
2025-11-29T17:20:35.362239729Z line 9992
2025-11-29T17:20:35.362240479Z line 9993
2025-11-29T17:20:35.362241229Z line 9994
2025-11-29T17:20:35.362241937Z line 9995
2025-11-29T17:20:35.362242729Z line 9996
2025-11-29T17:20:35.362243437Z line 9997
2025-11-29T17:20:35.362244187Z line 9998
2025-11-29T17:20:35.362244937Z line 9999

3. I setup Dozzle Agent on the VM
4. I setup Dozzle UI on my laptop and connected to the agent
5. I loaded the test container and started scrolling up. Each log was loaded and when it got to the very top it loaded the previous logs exactly as expected.

See the video:

test.mp4

I am not sure what else to try. 🤷

[ackava]

@amir20 my vms are remote, I am in India and all vms are in US east. Could you please enable bandwidth throttling in chrome debugger and see if you can reproduce the issue? And introduce some random delays in the logs to see if timing changes anything.

[amir20]

I'll give it a try. Although, I have logic to wait until pagination is done. If you want to help, then it would be great to figure out a way to easily reproduce. Dozzle is used by many people and this is a pretty sever bug in my opinion. So something is different. Looking at your screenshots, I can't make sense what's could be wrong.

[amir20]

Dozzle.mp4

Everything works on my side. Here is the video. I slowed it down to 4G. I also looked at the payload of the response and confirmed that it is returning up to a 100 logs per page.