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# Chapter 6: System Tools

## Query History Visualization Tool

IoTDB Query History Visualization Tool uses a monitoring web page to provide metrics service for viewing the query history and SQL execution time. It can also provide the memory and CPU usage of the current host.

The port of IoTDB Query History Visualization Tool is `8181`. Just print your `ip:8181` in your browser, and you can view page like this:

<img style="width:100%; max-width:800px; margin-left:auto; margin-right:auto; display:block;" src="https://user-images.githubusercontent.com/19167280/65688727-3038e380-e09e-11e9-8266-24ff0a1efa96.png">

> Note: Currently, we only support showing CPU ratio of Windows and Linux os. If you are using other OS, you may get a warning information: "Can't get the cpu ratio, because this OS is not support".
