As part of Dynatrace's commitment to data quality, we proactively identify and inactivate Private Last Mile, Last Mile, and Mobile tests that are malfunctioning in such a way that they return invalid data; or they lock up the Peers, which prevents them from running other tests (thus decreasing the overall fill rate and availability of our Peer network).
For the tests identified as failing in such a way, looking at the listed availability for the tests in the Synthetic Classic Portal can be misleading, since Private Last Mile, Last Mile and Mobile calculates "failure percentage" differently from Backbone.
For Last Mile, Private Last Mile, and Mobile tests, "failure" is defined as the system's inability to successfully get results for a given test.
If a test is sent out to the Peers and valid results are not returned (i.e. either the data returned was earmarked as invalid, or the test shut down the Peer so that no other tests could be run against it), it is considered a failure. If, on the other hand, results do come back, it is considered a success even if the test itself failed.
If a test is only returning 5% of its measurements, it has a 95% failure rate according to our internal systems. However, if of that 5% of measurements returned, only 50% are failed tests, the Portal would show the Availability at 50%, making the test look as if it is failing less than it actually is.
It is important that these tests be corrected before being reactivated, either by you or by our Test Engineers, to ensure that you receive valid, useful data, and your Peers and fill rates are not negatively impacted by a malformed script.