Live trace feed

[pulkin]

Thanks for an awesome tool!

Is it possible to have a live feed of trace events into the browser? If not, is it at least possible to have a live feed into a file?

[gaogaotiantian]

The most direct practical bottleneck is the front-end does not support it.

What do you mean to have a live feed into a file? The fundamental format of the trace file is json, which does not support appending.

The theoretically issue for live feeding, is actually performance. Currently viztracer is doing all to IO heavy work after the program is done, which takes a long time. Spreading the process into the program will slow down the program and skew the result quite a bit.

However, if you somehow filtered the data so the events are generated very slowly, that is possible - then it would be back to the front-end support which I have no control over.

A possible compromise is that - you don't get the fancy live-update front-end, but you can refresh the browser and retrieve the latest trace. It sounds interesting, but with a lot of challenges.

[pulkin]

I agree with pretty much everything. I guess there is more work on Perfetto side to support live event streams. Maybe there are other cool frontends to look into?

[gaogaotiantian]

Rendering GB-level trace is extremely difficult and I don't see any alternative to Perfetto (other than its deprecated predecessor chrome trace viewer). They put a lot of effort into the tool to make it as fast as possible.