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Technical info

1. Data storage

When every check is executed, we store a large amount of data. This data is used to populate the many detailed reports in Alertdesk and for troubleshooting.

1.1. What do we store

The data we store depends on the type and state of the check.

HTTP check UP

  • All request data like host, protocol, headers, etc.

HTTP check DOWN or FLAPPING

  • All request data like host, protocol, headers, etc.
  • Response Headers
  • Response Body (first 64kB uncompressed)

On assertions validating we use the full uncompressed Response Body. But we only store the first 64kB uncompressed.

1.2. Data retention

We store the check result data according to the following retention policy:

  • 1 minute is saved for 24 hours
  • 30 minutes is saved for 1 month
  • 1 hour is saved for 90 days (3 months)
  • 2 hours is saved for 180 days (6 months)
  • 1 day is saved for 1095 days (3 years)
  • 1 week is saved for 1825 days (5 years)
  • 1 month is saved forever

Disclaimer
We are continuosly working on uptimization of the platform. Expect updates to our retention policy.

2. Check data truncation

HTTP check truncates the response when 64 kilobytes have been read from the target host. This means assertion data must be placed within the first 64 kilobytes of data if the page response body exceeds this data limit.

3. Whitelist

All checks are executed from different locations in Amazon Web Services (AWS) cloud service. If you need to whitelist the traffic from Alertdesk in your firewalls, you can do this in 2 ways.

On every check, we, by default, add a default HEADER to the HTTP request.

User-Agent = Alertdesk/version

You can use this default User-Agent to whitelist the traffic from Alertdesk.

As the version number will change over time, you should only verify that the User-Agent contains the String Alertdesk.

3.1.1. Use a secret header

As our default user-agent is public for everyone, we recommend you to add your own HTTP header and use this for whitelisting.

Example with own header

3.1.2. Cloudflare

If you are using Cloudflare in front of your website, we recommend that you whitelist the traffic from Alertdesk, to avoid our check runner to get blocked.

Follow this step-by-step-guide to whitelist the Alertdesk User-Agent.

1. Choose website
Click on the website, where you wish to allow Alertdesk User-Agent.

Click on the website, where you wish to allow Alertdesk User-Agent
2. Firewall settings
Click on the firewall icon.

Click on the Firewall icon
3. Firewall Rules
1. Click on Firewall Rules in the submenu
2. Click the button Create a Firewall rule

Click on Firewall Rules
4. Create new firewall rule
1. Give your new rule a name
2. Select User Agent in the Field dropdown
3. Select Contains in the Operator dropdown
4. In the Value field enter Alertdesk
5. Select Allow in the Action drowdown
6. Finally, click on the Deploy button to confirm

Follow the instructions to add a new rule
5. Whitelisting enabled
The new firewall rule is now enabled.

Your new firewall rule is created

3.2. IP-address

Because we use AWS to host our platform, you need to whitelist the public list of IP-ranges from AWS:

See the full updated public list of AWS IP-ranges here

Maintaining these IP-ranges is a significant task as AWS is continuously updating them.

At the moment we don’t offer a static IP-range, but we recommend you to use HTTP headers for whitelisting.

5. Website Analytics

Services like Google Analytics uses javascript to collect the data. As our check runners don’t execute the javascript on your website, Google Analytics will not track the visits we make.

Updated on May 5, 2020