title: Async profiler overhead on Zing
body: <p>Our team is monitoring latency of our application using HdrHistograms. When I attach async profiler to it all percentiles increase dramatically.</p>
  <p>OS: Red Hat Enterprise Linux release 8.1 (Ootpa)</p>
  <p>JVM: 11.0.8-zing_20.08.2.0-b2-product-linux-X86_64</p>
  <p>This is what happens if I attach the profiler with flags -i 1000 -t:
  <a href="https://i.stack.imgur.com/FT1km.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/FT1km.png" alt="enter image description here" /></a></p>
  <p>This is what happens if I attach the profiler with flags -i 100000 -t:
  <a href="https://i.stack.imgur.com/hQ0BG.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/hQ0BG.png" alt="enter image description here" /></a></p>
  <p>Decreasing sampling frequency obviously decreases overhead, but it still remains large. I have two questions about it:</p>
  <ol>
  <li>Are there any other ways to decrease the profiling overhead other than reducing sampling frequency? Maybe there are some magical kernel/JVM flags?</li>
  <li>Does this overhead materially distort the profile itself?</li>
  </ol>
  <p>Thank you</p>