Duplicate custom counters can under certain circumstances lead to performance and/or data loss

PerformanceGuard can handle duplicate custom counters: If one or more custom counter templates applied to a specific agent configuration group contain identically defined custom counters (for example two custom counters defined as Object(Instance)\CounterName), PerformanceGuard will automatically detect this, use the custom counter that has the highest resolution, and ignore the other one. If the two identically defined custom counters have the same resolution, PerformanceGuard will use one of them and ignore the other. This ensures that you get the best possible performance as well as the most detailed data.

However, if one or more custom counter templates applied to a specific agent configuration group contain identical counters that have been defined in different ways, for example ...

... (where Object(Instance)\CounterName is already covered by Object(*)\CounterName), it can lead to the specific instance being picked up twice by PerformanceGuard. This causes a duplicate key violation, which can in turn lead to a decrease in the performance of PerformanceGuard and a risk of data loss.

The issue will be fixed in PerformanceGuard 7.1. Until then, if you use custom counters, make sure that you don’t define the same custom counter in different ways. In other words: Make sure that a specific instance isn't already covered by a * notation, like in the example above.