ignite-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Николай Ижиков <nizhikov....@gmail.com>
Subject Re: IgniteUtils#currentTimeMillis
Date Wed, 09 Aug 2017 11:59:51 GMT
Vladimir,

> There is nothing wrong with U.currentTimeMillis() at the
moment.

I think we can't rely on the return value for time measurement.
Is it true? Is it OK for you?

It very counterintuitive for me as newcomer.


2017-08-09 14:55 GMT+03:00 Vladimir Ozerov <vozerov@gridgain.com>:

> You cannot check it with benchmarks, because behavior of this method will
> vary between different JVMs, OSes and hardware. It can be different even
> with the same OS depending on it's settings. Again - let's just avoid
> unnecessary work. There is nothing wrong with U.currentTimeMillis() at the
> moment.
>
> On Wed, Aug 9, 2017 at 2:52 PM, Dmitry Pavlov <dpavlov.spb@gmail.com>
> wrote:
>
> > Vladimir, could we check it using benchmarks? Internet contains a lot of
> > articles about this issue. But do we know if it is still actual for new
> > VMs?
> >
> > ср, 9 авг. 2017 г. в 14:50, Dmitry Pavlov <dpavlov.spb@gmail.com>:
> >
> > > It seems System.currentTimeMillis () is now in intrinsic list. This
> means
> > > on modern JVMs performance penalty will not be so significiant.
> > >
> > > Nickolay, could you please raise standalone ticket for
> > U.currentTimeMillis
> > > () ?
> > >
> > > Could you also please check if system.nanoTime / system.currentTimeMs
> can
> > > fix https://issues.apache.org/jira/browse/IGNITE-5963 When you create
> a
> > > PR, I can start several run for Ignite Cache 6 suite to check if issue
> is
> > > still reprodacible.
> > >
> > > ср, 9 авг. 2017 г. в 14:41, Yakov Zhdanov <yzhdanov@apache.org>:
> > >
> > >> Nickolay, IgniteUtils#currentTimeMillis() is some kind of an old
> > heritage.
> > >> I guess nobody remembers when this method has been introduced. I agree
> > >> that
> > >> we can use System.currentTimeMillis(). I would suggest you file a
> ticket
> > >> and replace this method calls with System.currentTimeMillis(). Sounds
> > >> good?
> > >>
> > >> As far as reliable elapsed time measurement I agree with you that
> > >> nanoTime() is better here, but it is definitely not a reason for
> > mentioned
> > >> failure, since that test is launched in single JVM on a machine that
> > most
> > >> probably does not do any ntp syncs during the test to make Ignite's
> > >> timeout
> > >> machinery fail.
> > >>
> > >> Please file a ticket to switch Ignite's timeouts to nanoTime() at some
> > >> point.
> > >>
> > >> --Yakov
> > >>
> > >
> >
>



-- 
Nikolay Izhikov
NIzhikov.dev@gmail.com

Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message