Hi Venkat -- On Sun, Apr 14, 2013 at 12:43 PM, <mndv...@gmail.com> wrote: > Ramki, > > It is great to see quick response. > > If the user time is too high comparatively to real time means is it short of > resources also what I have observed my application certainly stopped more > than 5 mins at the same time GC user time showing 3+ minutes.
The ratio of user:real is really a rough indicator of the level of parallelism achieved by GC. For the example you had below:- >> Times: user=0.45 sys=0.00, real=0.09 secs 0.45/0.09 = 5 is the amount of parallelism in GC (of course not all of that might be useful work, so one can't with a straight face call it parallel speed-up, but still ...) > > I will send cpu details with GC logs tomorrow. OK. -- ramki > > Cheers, > Venkat > ------Original Message------ > From: Srinivas Ramakrishna > To: Venkateswarlu Mandadi > Cc: jdk6-dev@openjdk.java.net > Subject: Re: CMS output description > Sent: Apr 14, 2013 8:23 PM > > Hi Venkat -- > > user: process virtual user time, > sys: process-virtual system time > real: elapsed time > > Re: "Use showing more than 3 mins" : depends on how many cpus you have. > > Really, what should typically concern you, as a user of GC, is the > "real" time above, which is the duration for which your threads are > stopped > (when the time is associated with a stop-world pause). For concurrent > ops, it's the end to end elapsed time for that cycle, so should not > typically be of concern, as your application threads are running > during that time. > > cheers. > -- ramki > > > On Sat, Apr 13, 2013 at 1:37 PM, Venkateswarlu Mandadi > <mndv...@gmail.com> wrote: >> Hi, >> >> We are using CMS collector for oldgen (large heap -Xmx18g) and we have >> observed there is a long whole world stop, in GC logs it was observed that >> GC times are looking alright, but Times: Usr showing around more than 3 >> mins. >> >> Can someone explain Times fields >> >> Times: user=0.45 sys=0.00, real=0.09 secs >> >> Best Regards, >> >> Venkat > > Sent via my BlackBerry from Vodacom - let your email find you!
