Hi Bernd,<div><br></div><div>You're probably using those two flags along with -Xloggc:filename. This flag implies -XX:+PrintGCTimeStamps, which in your case is something you're trying to get rid of.</div><div><br></div>
<div>There's an easy workaround to this: put -XX:-PrintGCTimeStamps *after* -Xloggc.</div><div><br></div><div>The way HotSpot VM's argument processing works, if a VM flag is specified multiple times, then the one that comes last is the one used. This includes flags that are set implicitly.</div>
<div><br></div><div>There are different types of VM flags. "manageable" flags are ones that can be changed at runtime, via the HotSpotDiagnostic MBean. PrintGCTimeStamps is a manageable flag.</div><div><br></div>
<div>HTH,</div><div>Kris<br><br><div class="gmail_quote">On Wed, Aug 22, 2012 at 4:24 AM, Bernd Eckenfels <span dir="ltr"><<a href="mailto:bernd.eckenfels@googlemail.com" target="_blank">bernd.eckenfels@googlemail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hello,<br><br>I wondering about some strange behaviour. Sorry to bother with this minor observation, but I do hope the datestamp ioption gets more popular by mention it again .) <br>
<br>Often +PrintGCTimeStamps is recommended to be able to see the intervall between GC events. However I found some places talking about +PrintGCDateStamps which is much more convenient for some problems (for example correlating SLA violations with the STW pause times). <br>
<br>Some discusions suggest that you can combine both in a way that it does not print both timestamps:<br><br>-XX:+PrintGCDateStamps -XX:-PrintGCTimeStamps<br><br>However on the win 64bit JDKs 1.6.0_33 and 1.7.0_03 I have tried this, it does not work (i.e. the logfiles always contans both, actually the timestamp typically 2 times):<br>
<br>2012-08-21T22:08:29.989+0200: 1.292: [GC 1.292: [ParNew: 5033216K->3826K(5662336K), 0.0015120 secs] 5033216K->3826K(6710912K), 0.0015790 secs] [Times: user=0.00 sys=0.00, real=0.00 secs] <br>Total time for which application threads were stopped: 0.0018006 seconds<br>
2012-08-21T22:08:30.605+0200: 1.907: [GC 1.907: [ParNew: 5037042K->5230K(5662336K), 0.0023563 secs] 5037042K->5230K(6710912K), 0.0024133 secs] [Times: user=0.00 sys=0.00, real=0.00 secs] <br>Total time for which application threads were stopped: 0.0026457 seconds<br>
<br>Just some additional information: I was able to tuen off the timestamps in the HotSpotDiagnostics MBean:<br><br>2012-08-21T22:19:54.858+0200: [GC [ParNew: 5039624K->5836K(5662336K), 0.0030131 secs] 5349974K->316537K(6710912K), 0.0030753 secs] [Times: user=0.00 sys=0.00, real=0.00 secs] <br>
<br>Greetings<span class="HOEnZb"><font color="#888888"><br>Bernd<br>
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