LM OTel Collector Logging

Viewing Logs

Execute the following commands to view logs for each platform:

• Linux

journalctl -u lmotel

The systemd logs are stored in files /run/log/journal/machine-id/ or /var/log/journal/machine-id/ with the “.journal” suffix. /run is used when /var/log/journal is not available, or when Storage=volatile is set in the journald.conf configuration file.

• Docker

docker logs <container_id/name>

• Kubernetes

kubectl logs -f $(kubectl get pods --namespace=<namespace> -l app=lmotel -o name) -c lmotel -n <namespace>

Changing the Log-Level

Log-level, which defaults to INFO, can be changed by passing the –log-level flag to the lmotel process using the following:

./lmotel --config config.yaml --log-level <desired_log_level>

Supported log-levels include the following:

• DEBUG
• INFO
• WARN
• ERROR
• DPANIC
• PANIC
• FATAL

Logging Exporter

Logging exporter is used to dump telemetry data to the console via zap.Logger. It exports traces/metrics/logs depending on the pipeline.

Supported pipeline types include traces, metrics, and logs and can be used for the following:

• To verify whether traces (or any other telemetry data) has reached the OTel Collector
• To check the updated data after processing
  For example, if span-processor is configured in the pipeline to modify the span name, you can look at the logged traces in the console to check the updated value of span name.
• Other general debugging purposes

The following optional flags can be configured:

• loglevel (default = info): the log level of the logging export (debug|info|warn|error)
  When set to debug, pipeline data is verbosely logged.
• sampling_initial (default = 2): number of messages initially logged each second
• sampling_thereafter (default = 500): sampling rate after the initial messages are logged (every Mth message is logged)
  See the following documentation from Zapcore for information on how sampling parameters impact the number of messages:
  https://pkg.go.dev/go.uber.org/zap/zapcore#NewSampler
  

exporters:
  logging:
    loglevel: debug
pipelines:
 traces:
   receivers: [nop]
   processors: [nop]
   exporters: [logging]

Console Log Information

You can check the following information in the console logs:

• To check whether LM OTel Collector is registered successfully with which Collector ID, search for the following in the logs:
  “Collector registered successfully!!”
  The Collector ID is at the end and looks similar to the following:

2021-10-01T09:52:07.015Z info lmextension/lmextension.go:176 Collector registered successfully!! {"kind": "extension", "name": "lmextension", "id": "23754"}

• To check whether lmotel is running, look for something similar to the following:

2021-10-01T09:52:07.022Z info service/collector.go:134 Everything is ready. Begin running and processing data.

• To check whether config file is updated successfully, search for the following:

Config file changed. Reloading lmotel...

• To check if credentials were rotated successfully, search for the following:

Credentials updated successfully!!