python: app metadata: NoSuchProcess causing ERROR logs

[Jongy]

Flaky test failure stemming from:

[2022-09-26 23:57:39,114] ERROR: gprofiler.metadata.application_metadata: Exception while collecting metadata in PythonMetadata!
Traceback (most recent call last):
  File "gprofiler/metadata/application_metadata.py", line 67, in get_metadata
  File "gprofiler/profilers/python.py", line 143, in make_application_metadata
  File "granulate_utils/linux/elf.py", line 37, in get_elf_id
  File "granulate_utils/linux/elf.py", line 18, in get_elf_buildid
FileNotFoundError: [Errno 2] No such file or directory: '/proc/3128/exe'
[2022-09-26 23:57:39,116] DEBUG: gprofiler.profilers.profiler_base: PySpyProfiler: process went down during profiling 3128 (lsb_release)
Traceback (most recent call last):
  File "granulate_utils/linux/process.py", line 104, in _translate_errors
  File "granulate_utils/linux/process.py", line 69, in read_proc_file
FileNotFoundError: [Errno 2] No such file or directory: '/proc/3128/status'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "gprofiler/profilers/profiler_base.py", line 119, in _wait_for_profiles
  File "concurrent/futures/_base.py", line 425, in result
  File "concurrent/futures/_base.py", line 384, in __get_result
  File "concurrent/futures/thread.py", line 56, in run
  File "gprofiler/profilers/python.py", line 203, in _profile_process
  File "gprofiler/utils/process.py", line 20, in process_comm
  File "granulate_utils/linux/process.py", line 70, in read_proc_file
  File "contextlib.py", line 99, in __exit__
  File "granulate_utils/linux/process.py", line 114, in _translate_errors
psutil.NoSuchProcess: psutil.NoSuchProcess process no longer exists (pid=3128)

This should not be an ERROR - this error should be ignored silently as it is okay for processes to go down.

Only the ERROR one is a problem here.

[Jongy]

We call get_elf_id("/proc/pid/exe") at multiple sites. We can create a wrapper that'll do it & catch the FileNotFoundError and if the error path is the /proc/pid/exe one, replace the exception with NoSuchProcess.

Likewise we have get_mapped_dso_elf_id which reads a file from /proc/pid/root/path. It needs to be fixed as well.

[Jongy]

Another example where this happens and fails the test: https://github.com/Granulate/gprofiler/actions/runs/3105234649/jobs/5030894845

[Jongy]

@mpozniak95 , now with intel/granulate-utils#87 merged you can open a PR in this repository that bumps the git revision. We'll merge it after #483 is merged (to avoid multiple updates in the same PR)