NerdKey

Powered by NerdTools.co.uk Uptime Tracker (http://uptime.nerdtools.co.uk/) this plugin will add a widget to your sidebar that will show the percentage of availability or uptime for any website over the last 30 days.
In terms of the tracking system, checks are carried out every 5 minutes from different locations and then averages are worked out to form the overall reports from which the graph is generated and shown via an iframe.
Other reports including hourly, weekly and daily can be seen by visiting the Uptime Tracker website directly.
<h3>Arbitrary section 1</h3>

Uptime Widget

Adds a simple uptime gauge to your WordPress sidebar, showing the percentage of availability for any website over the past 30 days.

nabtron

Show average server load and uptime of your linux server on top in admin panel. It contains three values, first one is the load average for last 15 minutes, second one is for 5 minutes, third one is for last 1 minute.
Now you can easily monitor your server load in real time whenever you want without installing any script or moving out of your wordpress admin panel.
Options include turn off, on or legacy mode.
It shows:
<ul>
<li>3 averages for server load</li>
<li>server uptime in days and hours</li>
<li>Memory usage in %age</li>
</ul>
If useful – Future versions are planned to have more options, so please leave a feedback
Found a bug or have a feature request ? <a href="https://nabtron.com/wp-server-plugin/" rel="nofollow ugc">Report here</a>

WP Server

Show average server load and uptime of your linux server on top in admin panel

Uptime Widget vs WP Server