<html><head></head><body><div class="ydp22b3a1eayahoo-style-wrap" style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:13px;"><div id="ydp22b3a1eayiv8476357521"><div style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:13px;" class="ydp22b3a1eayiv8476357521ydpa5ea0959yahoo-style-wrap"><div id="ydp22b3a1eayiv8476357521ydpa5ea0959yiv6837152661"><div style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:13px;" class="ydp22b3a1eayiv8476357521ydpa5ea0959yiv6837152661yahoo-style-wrap"><div dir="ltr" data-setdir="false"> <div><p class="ydp8fcd31f0MsoNormal">Hi there,</p>
<p class="ydp8fcd31f0MsoNormal">I would appreciate some high-level details about how Gen-ZGC
is promoting objects from Young to Old. I can observe in the logs that tenuring
threshold is computed in runtime for every young collection, BUT I am NOT able
to fully understand the strategy.</p>
<p class="ydp8fcd31f0MsoNormal">It looks to me that when allocation rate is higher the
tenuring threshold is decreased and objects promotion happens faster (Both
because tenuring threshold is lower and because there are more frequent GC
cycles). Is that correct? In our logs we observe the tenuring threshold
fluctuating between 1 and 12 (and then Young has Eden + N survivor areas). My
feeling is that in some situations, object promotion could be a bit aggressive
and reclaiming the memory in the Old Generation will take a while.</p>
<p class="ydp8fcd31f0MsoNormal">Is there any way to influence the promotion algorithm (e.g.
guarantee a minimum of GC cycles)? I fully understand the ZGC strategy to avoid
too much tuning and I agree that strategy is correct, BUT I ask the question
just in case (I did NOT find anything in the WIKI, JEP or articles,
presentations).</p>
<p class="ydp8fcd31f0MsoNormal">A side effect in our case is that we monitor Old Generation
size to take some decisions (e.g. protect new data is provision in the
DB...) and in some cases, our system is overreacting.</p>
<p class="ydp8fcd31f0MsoNormal">Thanks in advance,</p>
<p class="ydp8fcd31f0MsoNormal">Evaristo</p>
<p class="ydp8fcd31f0MsoNormal"> </p></div><br></div></div></div></div></div></div></body></html>