debug if not sending logs?

[juju4]

How to troubleshoot when a log (file in my case) does not seem to be sent to upstream?
I have "Started watching file" in otel-collector journalctl but nothing on receiving server.

I tried adding to exporter settings following but does not getting much more

  debug:
    verbosity: detailed
    sampling_initial: 5
    sampling_thereafter: 200

only error level message is error journald/input.go:107 journalctl command exited {"kind": "receiver", "name": "journald", "data_type": "logs", "operator_id": "journald_input", "operator_type": "journald_input", "error": "signal: terminated", "output": ""} which is likely unrelated

otelcol-contrib version is 0.111.0 on linux ubuntu 22.04.
I have logs file and journald that are sending data.

[juju4]

tried adding a local file exporter but not getting anything

exporters:
  # https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/main/exporter/fileexporter/README.md
  file/debug:
    path: /tmp/otel-debug.log
    rotation:
      max_megabytes: 10
      max_days: 3
      max_backups: 3
      localtime: false
    format: json
    # compression: zstd
[...]

service:
[...]
    logs/journald:
      receivers: [journald]
      processors: [resourcedetection/system, memory_limiter, batch]
      exporters: [otlphttp/openobserve_journald, file/debug]
[...]

[juju4]

Found issue for /tmp/otel-debug.log. I had a chown permission issue and PrivateTmp=true set for systemd unit. fixed.

[juju4]

One issue that I identified is journalctl follow that is used by otel-collector does not seem to work well with unit alias. must use real systemd unit name.