If you wish to be notified when one of your services goes down, you could make use of the WorldStream monitoring system. Currently there are two types of monitors enabled, which are ICMP and TCP.

All the monitors are being executed by our probes, which can be recognized by the following IP addresses:

  • 185.21.63.25 (customer-probe01.worldstream.nl)
  • 185.21.63.26 (customer-probe02.worldstream.nl)

The monitor checks are executed at least once every 60 seconds. When a check returns “FAIL”, the check is rescheduled to be executed 30 seconds after the finished-time of the failed check. If the check returns a “FAIL” three times in one sequence, the service is considered as “DOWN”, and a notification will be sent to the configured email(s)/phone-number(s). The monitor will restore to “UP” as soon as three consecutive checks return a “SUCCESS” result.

ICMP-check

One check consists of three ICMP Echo requests(8) at an interval of one per 1.1 second. If the executor doesn’t receive three ICMP Replies(0) within 500 milliseconds the check is considered as “FAIL”.

TCP-check

The check can be configured at any port-number in the range of 1-65535. The executor tries to open a connection, if this connection cannot be established the check is considered as “FAIL”. If the connection has been opened, the executor will close it immediately and returns “SUCCESS”.

Whitelisting our IP addresses

To ensure no false positives are triggering notifications, we advise you to whitelist the IP addresses mentioned above to bypass any rate-limiters or firewall-blocks.