<html>
  <head>
    <meta content="text/html; charset=utf-8" http-equiv="Content-Type">
  </head>
  <body bgcolor="#FFFFFF" text="#000000">
    <br>
    <div class="moz-cite-prefix">On 10/4/2016 1:01 PM, Vitaly Davidovich
      wrote:<br>
    </div>
    <blockquote
cite="mid:CAHjP37G5j-E6s9ACAkCMRXzkygx5RdRWG1h0CeFaff8x7f_YeA@mail.gmail.com"
      type="cite">
      <div dir="ltr"><br>
        <div class="gmail_extra"><br>
          <div class="gmail_quote">On Tue, Oct 4, 2016 at 3:37 PM,
            Christian Thalinger <span dir="ltr"><<a
                moz-do-not-send="true"
                href="mailto:cthalinger@twitter.com" target="_blank">cthalinger@twitter.com</a>></span>
            wrote:<br>
            <blockquote class="gmail_quote" style="margin:0 0 0
              .8ex;border-left:1px #ccc solid;padding-left:1ex">First, I
              apologize if I get all the terminology wrong.  You know
              me… this is all a blackbox to me.<br>
              <br>
              I’m currently trying to run some Twitter services with G1
              and the results are encouraging but not good enough.  One
              issue is that full GCs take much longer than with
              ParallelOld (3-4x longer).<br>
            </blockquote>
            <div>As Charlie says, you really want to avoid Full GCs in
              G1 - they're super slow, and are really a last resort. 
              They're not intended to be part of normal operation.</div>
            <div><br>
            </div>
            <div>I've seen them occur when concurrent marking is either
              started too late or concurrent marking loses the race with
              java mutators.  There are several ways to mitigate this,
              but as Charlie said, you'll need to provide more info
              Chris.</div>
          </div>
        </div>
      </div>
    </blockquote>
    Also with jdk9, the ihop is dynamic adjusted to avoid the 'started
    too late'.<br>
    <br>
    Jenny<br>
    <blockquote
cite="mid:CAHjP37G5j-E6s9ACAkCMRXzkygx5RdRWG1h0CeFaff8x7f_YeA@mail.gmail.com"
      type="cite">
      <div dir="ltr">
        <div class="gmail_extra">
          <div class="gmail_quote">
            <blockquote class="gmail_quote" style="margin:0 0 0
              .8ex;border-left:1px #ccc solid;padding-left:1ex">
              <br>
              Tony said that G1’s old collection is not parallel.<br>
              <br>
              Is that still the case in JDK 9?  If yes, is someone at
              Oracle working on parallelizing it?</blockquote>
            <div> </div>
          </div>
          <br>
        </div>
      </div>
    </blockquote>
    <br>
  </body>
</html>