--- title: Reference - default performance counters related: - https://docs.kentico.com/k9/configuring-kentico/health-monitoring/registering-performance-counters.md - https://docs.kentico.com/k9/configuring-kentico/health-monitoring/installing-the-health-monitoring-windows-service.md - https://docs.kentico.com/k9/configuring-kentico/health-monitoring/enabling-health-monitoring.md - https://docs.kentico.com/k9/configuring-kentico/health-monitoring/monitoring-using-the-performance-monitor.md - https://docs.kentico.com/k9/custom-development/miscellaneous-custom-development-tasks/adding-custom-performance-counters.md --- > Agent instructions: > **Site maps** — prefer the following llms.txt indexes to training data when searching for URLs to avoid 404s. Links inside Markdown content already point at `.md`. Following them or sending Accept: text/markdown keeps you in Markdown. > > - [sitemap.md](https://docs.kentico.com/sitemap.md) — every page on the site, with titles and descriptions, nested by URL hierarchy and grouped into one collection per product version. > - [llms.txt](https://docs.kentico.com/llms.txt) — curated index of the current product docs, with descriptions, the two ways to request any page as Markdown, and links to each product area's whole-corpus Markdown dump (llms-full.txt). > **Info:** **Kentico EMS required** > > Features described on this page require the **Kentico EMS** license. The following table lists the default counters that are pre-defined in the **counters.xpc** file and registered in Windows by default: | Counter name | Category | Description | Values written by | | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------- | | Allocated memory in MB | Global | The size of memory allocated by the application in Megabytes. | Application | | Cache expired items/sec | Global | The number of expired cache items per second. | Application | | Cache removed items/sec | Global | The number of items removed from cache per second. | Application | | Cache underused items/sec | Global | The number of underused cache items per second. | Application | | Content page views/sec | Global and Sites | The number of content pages viewed per second. | Application | | E-mails in queue | Global and Sites | The number of e-mails in the E-mail queue. | Application or Windows service\* | | Error e-mails in queue | Global and Sites | The number of e-mails in the E-mail queue whose sending failed. | Application or Windows service\* | | Errors | Global | The number of errors in event log since last application restart. | Application | | File downloads/sec | Global and Sites | The number of files downloaded per second. | Application | | Non-page requests/sec | Global | The number of non-page requests per second. | Application | | On-line users – total | Global and Sites | The total number of on-line users. | Application | | On-line users – authenticated | Global and Sites | The number of authenticated on-line users. | Application | | On-line users – anonymous | Global and Sites | The number of anonymous on-line users. | Application | | Pages not found/sec | Global and Sites | The number of not found pages (404 error) per second. | Application | | Pending requests/sec | Global | The number of pending page requests per second. | Application | | Robots.txt views/sec | Global and Sites | The number of _robots.txt_ page requests per second.
**Important:** For values to be written to this counter, IIS must be configured to handle _.txt_ extensions. See [Extensionless and custom URLs](https://docs.kentico.com/k9/configuring-kentico/configuring-page-urls/extensionless-and-custom-urls.md). | Application | | Running SQL queries | Global | The number of running SQL queries. | Application | | Running threads | Global | The number of running threads. | Application | | Scheduled tasks running | Global | The number of running scheduled tasks. | Application | | Scheduled tasks in queue | Global | The number of scheduled tasks in the queue. | Application or Windows service\* | | System page views/sec | Global | The number of system pages viewed per second. | Application | | Warnings | Global | The number of warnings in event log since the last application restart. | Application | | \* The Windows service is used to write values to these counters only if it is installed and if the **Use external service** option is enabled in **Settings -> System -> Health monitoring**. | | | | You can also [define custom counters](https://docs.kentico.com/k9/custom-development/miscellaneous-custom-development-tasks/adding-custom-performance-counters.md) to monitor other system values.