prometheus / prometheus/client_python

Multiprocess application sometimes throwing UnicodeDecodeError in prometheus_client/mmap_dict.py

Open
#868 3 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Dominant language
Python
Stars
4.4k
Forks
876
Avg merge
8d 4h
Merged PRs (30d)
1

Description

Hi
I have multiprocess enabled application with flask exporter, sometimes it is throwing below error
File "usr/local/lib/python3.8/site-packages/prometheus_client/mmap_dict.py", line 44, in _read_all_values
yield encoded_key.decode('utf-8'), value, pos
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xf0 in position 18: invalid continuation byte.

After this error my application is crashed. Can someone please help me on this?

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start in prometheus_client/mmap_dict.py at _read_all_values and inspect how multiprocess mmap data reaches encoded_key.decode('utf-8'). Reproduce the failure with a multiprocess application using the Flask exporter, then verify that the resulting UnicodeDecodeError no longer crashes the application.

Written by the indexing model from the issue text.

Assessment

Tech stack
prometheus, python
Domain
observability-sre
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
35/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.