If your Outage handling settings in Dynatrace for your synthetic test is configured to alert when 1 location is unable to access your web application on first occurence, then yes it will create a problem and alert for this failure. If you do not want it to alert on this, there are a couple of options
Please let me know if this works for you or if you need clarification on anything.
Are you asking if an alert will be created if the Dynatrace node where the test is executed from is offline or down for some reason? That is it is unable to run the synthetic test? If that is what you are asking, it should not create an alert because if the Dynatrace node is offline or down for some reason, the synthetic test should not run at that location.
Yes, that is what I am asking. If the Dynatrace node has some DNS issues or other infrastructure issues and when the synthetic test fails because of such errors, then does those failures trigger alert?
Can you please confirm if the Synthetic tests do not run for any Dynatrace infrastructure issues?
What happens if one node is down/offline and 2 other locations are good while my outage threshold is set to 3/all locations unavailable? Does it generate a problem?
No it will not generate a problem as the threshold is to alert only when all 3 locations are unavailable. As 2 are fine, no alert will be created. For your other question, I am not exactly sure what the Availability SLA is for synthetic nodes but there is a lot of resiliency involved for the nodes in various locations. It isn't just dependent on a single infrastructure at a node location. You may want to discuss with your sales resource what this availablity SLA is for synthetic nodes and the details on the resiliency and failover for the nodes.
Hope This Helps