heap samples are not what I expect about holmes

[doujiang24]

As golang/go#54223 (comment) said, heap profiles are only updated when the gc runs.
Actually, it's a go heap profile related issue, not a holmes related issue.
For more details, please see:
https://mosn.io/blog/posts/mosn-holmes-design/#%E6%A0%B9%E6%8D%AEgc%E5%91%A8%E6%9C%9F%E9%87%87%E9%9B%86
https://uncledou.site/2022/go-pprof-heap/

Hope this could help you.

[dumbFeng]

@doujiang24 Nice! Thank you.

[dumbFeng]

But I think they are two different situations. About the one I proposed, I think holmes should dump after next gc runs while the heap peak occurs. In the following processes, the heap profiles are stale and cann't help us find out what incurs the problem:

1. gc runs
2. heap peak happens. Such as making a big slice
3. holmes dumps
4. next gc runs

[cch123]

You should see both the inuse and alloc space together to help locating the root cause

A big heap object will cause rss spike, if it is not used any more later, it will not appear on the inuse object pprof list, but you can find it in the alloc object list

All objects allocated after app started will be counted in the alloc objects/space