# system\_stats

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This extension is **OPTIONAL** and should be considered solely when you decide to employ the [Agentless approach](https://docs.datasentinel.io/manual/features/other-features/agentless-monitoring) for monitoring your PostgreSQL instances**.**
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### Installation

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To be installed in the internal database named **postgres**
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For detailed installation instructions of the extension, please consult the GitHub repository <https://github.com/EnterpriseDB/system_stats><br>

You need to grant the role monitor\_system\_stats to the monitoring user.

```sql
// example
GRANT monitor_system_stats to datasentinel;
```

### Monitored metrics

When the **system\_stats** extension is installed, Datasentinel (using the [agentless method](https://docs.datasentinel.io/manual/features/other-features/agentless-monitoring)) starts gathering system metrics directly from PostgreSQL clusters at regular intervals. This is achieved by running SQL queries, which enables Datasentinel to collect detailed system metrics without needing a local agent on each server. <br>

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With this setup, you can browse and analyze these metrics with the same level of precision and granularity as you would expect if a local agent were installed.\
\
Refer to [Cluster & System Metrics](https://docs.datasentinel.io/manual/features/key-features/cluster-and-system-metrics) for more details.
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**Metrics**:

* System information
* CPU load
* CPU usage
* Memory usage
* Network usage
* Swap usage
* I/Os statistics
* File-systems usage