Log Monitor

Reminder !!

Ensure the Pre-Requisites are in place before you proceed.

logMonitor.sh is a general purpose JSON log monitoring script for traces created by cardano-node. Currently, it looks for traces related to leader slots and block creation but other uses could be added in the future.

Block traces⚓︎

For the core node (block producer) the logMonitor.sh script can be run to monitor the JSON log file created by cardano-node for traces related to leader slots and block creation.

For optimal coverage, it's best run together with CNCLI scripts as they provide different functionalities. Together, they create a complete picture of blocks assigned, created, validated or invalidated due to node issues.


The script is best run as a background process. This can be accomplished in many ways but the preferred method is to run it as a systemd service. A terminal multiplexer like tmux or screen could also be used but not covered here.

Use the deploy-as-systemd.sh script to create a systemd unit file (deployed together with CNCLI). Log output is handled by syslog and end up in the systems standard syslog file, normally /var/log/syslog. journalctl -f -u cnode-logmonitor.service can be used to check service output (follow mode). Other logging configurations are not covered here.

View Blocklog⚓︎

Best viewed in CNTools or gLiveView. See CNCLI for example output.