Seems like the query "stuck" and return the same value (probably latest value)

[benrurepo]

Describe the bug
randomly getting the error:

[error    ] database error                 database=<hostname>
Traceback (most recent call last):
  File "/virtualenv/lib/python3.13/site-packages/query_exporter/db.py", line 482, in connect
    await self._conn.open()
  File "/virtualenv/lib/python3.13/site-packages/query_exporter/db.py", line 346, in open
    self._create_worker()
    ~~~~~~~~~~~~~~~~~~~^^
  File "/virtualenv/lib/python3.13/site-packages/query_exporter/db.py", line 378, in _create_worker
    assert not self._worker
           ^^^^^^^^^^^^^^^^
AssertionError

Also, seems like the query "stuck" and return the same value (probably latest value)

A clear and concise description of what the bug is and when it happens.

Installation details
Using helm chart

keep-connection: false

• operating system: [OS and version]
  EKS
• query-exporter installation type:
  • docker image: tag: "3.2.1"

To Reproduce
we are not sure how to reproduce - its happening randomly
we have changed from replicacount: 2 to replicacount: 1 but problem still exist

If possible, please provide detailed steps to reproduce the behavior:

1. Config file content (redacted of secrets if needed)
   As describe in the readme

2. Ran query-exporter with the following command line ...
   args: ["--config", "./config1.yaml", "--config", "./config2.yaml"]

3. Got the error when

• running on EKS
• replicacount: 1 or 2 - still getting the error
• different databases - each DB have dedicated pod and this happening in all of the pods
• resting the pod "fix" the problem and the problem return randomly after few hours
• tcpdump on the pod show no traffic when we see the error

[albertodonato]

cloud you please include full log from when the error happens?
It seems likely that the connection got closed but the logic it's expecting an active connection at that point.

[sebschlue]

I also experience the same issue, also version 3.2.1.

config:

databases:
  postgres_xxx:
    dsn: !file /vault/secrets/xxx-connection.properties
    keep-connected: false
    labels:
      app: xxx
      env: prod
. . . 
. . . 
. . . 

File /vault/secrets/xxx-connection.properties has:

postgresql+psycopg://user:pass@host:5432/db

error:

AssertionError                                                                                                                                                                                
2025-12-03 11:02:50 [error    ] database error                 database=postgres_xxx                                                                                                     
Traceback (most recent call last):                                                                                                                                                            
  File "/usr/local/lib/python3.12/site-packages/query_exporter/db.py", line 482, in connect                                                                                                   
    await self._conn.open()                                                                                                                                                                   
  File "/usr/local/lib/python3.12/site-packages/query_exporter/db.py", line 346, in open                                                                                                      
    self._create_worker()                                                                                                                                                                     
  File "/usr/local/lib/python3.12/site-packages/query_exporter/db.py", line 378, in _create_worker                                                                                            
    assert not self._worker                                                                                                                                                                   
           ^^^^^^^^^^^^^^^^                                                                          

This seems to be a hard error, in the sense that the pod never recovers from this situation and needs a restart.

Dockerfile:

FROM docker.io/library/python:3.12.3

RUN pip install --no-cache-dir --upgrade pip && pip install --no-cache-dir query-exporter==3.2.1 psycopg==3.2.10

VOLUME ["/config"]

EXPOSE 9560

CMD ["query-exporter", "-H0.0.0.0", "--config", "/config/config.yaml"]

Will update python to 3.12.12 and psycopg to 3.3.1 and then report back.

[sebschlue]

still the same issue. the pod does not recover even with setting "keep-connected: false"

[albertodonato]

Could you please test with version 4, which has a reimplemented logic for connection handling?

[sebschlue]

Now testing with version 4.0.0