Varnish Cache ships with useful monitoring and logging tools, including `varnishstat` which provides detailed performance metrics such as cache hits and misses, resource consumption, threads created, and more. The tool allows users to list specific values by passing them with the `-f` flag. For instance, to display the number of threads currently being used, one can run `varnishstat -f MAIN.threads`. Additionally, `varnishlog` provides detailed information about each individual request, while `varnishtop`, `varnishhist`, and `varnishsizes` offer specialized tools to filter and analyze log entries. The choice of metrics to monitor depends on the use case, available tools, and the insight provided by a given metric. A built integration with Varnish allows users to collect and monitor its metrics with minimal setup, and further details can be found in the next part of the series.