Sampling
When sampling is enabled, JProfiler inspects the call stacks of all
threads periodically. Sampling has extremely low overhead
even without any filters. Accuracy of non-timing related stack information (like allocation
information) is low and invocation counts are not available. Only methods that take
longer
than the sampling period or methods called frequently are captured by sampling.
Sampling is ideally suited for use without any method call filters. To temporarily
switch off
all filters, you can use the Disable all filters for sampling setting
instead of deleting all filters in your configuration. In that way you can create
a profiling
settings template that ignores your filter configuration and alternate between using
filters and
using no filters at all.
If sampling is enabled, the sampling frequency can be adjusted. The default value is 5 ms.
A lower sampling frequency incurs a slightly higher CPU overhead when profiling.
Note: allocations will be reported according to the call traces
recorded by the sampling procedure. This may lead to incorrect allocation spots.