014_thin_edge_logs.md

The thin-edge logs

The logs that are useful for debugging thin-edge.io break down into logs that are created by thin-edge itself and by third party components.

Thin-edge logs

On a thin-edge device different components like mappers, agent, and plugins run. The log messages of these components can be accessed as below. The logs here capture INFO, WARNING, and ERROR messages.

Cloud mapper logs

The thin-edge cloud mapper component that sends the measurement data to the cloud can be accessed as below.

Tedge Cumulocity mapper

The log messages of the Cumulocity mapper component that sends the measurement data from the thin-edge device to the Cumulocity cloud can be accessed as below

journalctl -u tedge-mapper-c8y.service

Note: Run tedge_mapper --debug c8y to log more debug messages

Tedge Azure mapper

The log messages of the Azure mapper component that sends the measurement data from the thin-edge device to the Azure cloud can be accessed as below.

journalctl -u tedge-mapper-az.service

Note: Run tedge_mapper --debug az to log more debug messages

Device monitoring logs

The thin-edge device monitoring component logs can be found as below

Collectd mapper logs

The log messages of the collectd mapper that sends the monitoring data to the cloud can be accessed as below

journalctl -u tedge-mapper-collectd.service

Note: Run tedge_mapper --debug collectd to log more debug messages

Software Management logs

This section describes how to access the software management component logs

Software update operation log

For every new software operation (list/update), a new log file will be created at /var/log/tedge/agent. For each plugin command like prepare, update-list (install, remove), finalize, and list, the log file captures exit status, stdout, and stderr messages.

Tedge Agent logs

The agent service logs can be accessed as below

journalctl -u tedge-agent.service

For example: tedge-agent logs plugin calls finalize and list.

tedge-agent : TTY=unknown ; PWD=/tmp ; USER=root ; COMMAND=/etc/tedge/sm-plugins/apt finalize

tedge-agent : TTY=unknown ; PWD=/tmp ; USER=root ; COMMAND=/etc/tedge/sm-plugins/apt list

Note: Run tedge_agent --debug to log more debug messages

Thirdparty component logs

Thin-edge uses the third-party components Mosquitto as the mqtt broker and Collectd for monitoring purpose. The logs that are created by these components can be accessed on a thin-edge device as below.

Mosquitto logs

Thin-edge uses Mosquitto as the mqtt broker for local communication as well as to communicate with the cloud. The Mosquitto logs can be found in /var/log/mosquitto/mosquitto.log. Mosquitto captures error, warning, notice, information, subscribe, and unsubscribe messages.

Note: Set log_type debug or log_type all on /etc/mosquitto/mosquitto.conf, to capture more debug information.

Collectd logs

Collectd is used for monitoring the resource status of a thin-edge device. Collectd logs all the messages at /var/log/syslog. So, the collectd specific logs can be accessed using the journalctl as below

journalctl -u collectd.service