Debugging and logging in Blocks

This guide explains how to debug Blocks and access logs, and outlines the supported scope of Block-level logging.

Contensis provides basic operational logging for Blocks to help diagnose simple issues such as:

• application startup failures
• runtime errors
• request handling problems

Block logging is not intended to replace full application logging or observability tooling.

For production-grade logging, tracing, and monitoring, you should integrate a third-party logging solution directly into your application.

Block logs can be viewed using the Contensis UI or the Contensis CLI.

Users with the required permissions can view the console logs of Blocks from the Blocks screen inside Contensis.

See our article on viewing the console logs for a Block for more information and a step-by-step guide.

This command:

• retrieves recent logs
• streams new log output
• shows logs from all data centres

You can view the CLI documentation for getting Block logs here.

1. Run the container locally
   If the issue occurs locally, it is not Block-specific.
2. Check manifest.json
   Ensure port and routing settings match your application.
3. Verify routing configuration
   Confirm Site View nodes and renderers are correctly mapped.
4. Review logs across all data centres
   Errors may appear in only one location.

For advanced logging, metrics, and alerting, integrate a third-party service into your application.

Common options include:

• Loggly – hosted log aggregation and search
• Datadog – logs, metrics, and application performance monitoring
• New Relic – application monitoring and distributed tracing
• Splunk – enterprise log aggregation and analytics
• Elastic Stack (ELK) – self-hosted or managed logging and search

These tools allow you to:

• centralise logs
• correlate errors across services
• set alerts and dashboards
• retain logs long-term

Use Contensis Block logs for:

• basic validation
• early troubleshooting
• environment verification

Use third-party tooling for:

• production monitoring
• performance analysis
• long-term log retention
• incident investigation