OpsDash comes with the ability to load your public HTTP and HTTPS pages from locations around the world, and monitor the following metrics:
The URL load time, split up into it's components:
DNS resolution time
TCP connection establishment time
TLS handshake time (for HTTPS URLs)
wait time (the time elapsed between sending the request and receiving the first byte response)
Time to First Byte (TTFB) - widely accepted metric for a quick assessment of responsiveness
The number of reachable locations - currently OpsDash will try to reach your URL from three locations around the world:
Certificate Expiry - for HTTPS URLs, the number of days remaining before the TLS certificate expires
URLs will be fetched every minute from three locations. This is currently not modifiable.
All time measurements have millisecond resolution. Certificate expiry is tracked in days.
Here is how an uptime monitoring dashboard looks, out of the box:
To get started, go to https://app.opsdash.com/uptime to add a new uptime monitor. You will see a UI like this:
Fill out the fields under the "Add New Uptime Monitor" section and then hit the "Add" button:
Name - a name for your monitor. Should consist only of letters, numbers and "-". If you're entering multiple URLs, a running number "-1", "-2" etc will be appended to the name to create multiple monitors.
Timeout - the timeout for fetching the URL, between 10 and 50 seconds. If omitted, defaults to 10 seconds.
Method - the HTTP method to use, one of: GET, PUT, POST, OPTIONS or PATCH.
Headers - any extra HTTP headers to include while making the request. You can add up to 10 headers, one per line, each line of the format "Header-Name: Header-Value". Header names can be repeated.
URLs - add one or more URLs, up to 100, one per line. URL scheme must be "http" or "https". If you specify more than one URL, separate monitors will be created, sharing the same values for timeout, method and headers.
You can edit an existing monitor with the "Edit" link, and delete it with the "Delete" link in the list of monitors. Note that deleting a monitor will delete all associated historical metric data also.
Alerts can be set as usual for any graph. There are a couple of thresholds set by default -- if the "Reachable Count" falls below 3 it is a warning, and below 2 is a critical.
For example, to set a warning threshold of 1 second on the TTFB from London, you can do:
If you need to open your firewalls to allow incoming HTTP(S) requests from OpsDash for uptime monitoring, these are our IPs:
The "User-Agent" field of the HTTP request will contain the string "OpsDash".
Pricing details can be found on the OpsDash Pricing page.