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Posted to user@hbase.apache.org by Sujee Maniyam <su...@sujee.net> on 2011/11/08 22:57:55 UTC
hbase heap size beyond 16G ?
HI All
the HBase book by Lars warns it is not recommended to set heap size above
16G, because of 'stop the world' GC.
Does this still apply? Specially with 'concurrentGC' ?
thanks
Sujee
http://sujee.net
Re: hbase heap size beyond 16G ?
Posted by N Keywal <nk...@gmail.com>.
If your're interested, some good slides on GC (slide 45 and after):
http://www.azulsystems.com/sites/www.azulsystems.com/SpringOne2011_UnderstandingGC.pdf
On Tue, Nov 8, 2011 at 11:25 PM, Mikael Sitruk <mi...@gmail.com>wrote:
> Concurrent GC (a.k.a CMS) does not mean that there is no more pause. The
> pauses are reduced to minimum but can still happen especially if the
> concurrent thread will not finish their work under high pressure. The G1
> collector in JDK 7.0 pretends to be a better collector than CMS, but i
> presume tests will need to be done to validate this.
> BTW the CMS collector is the one that is recommented in the book.
>
> Mikael.S
>
> On Tue, Nov 8, 2011 at 11:57 PM, Sujee Maniyam <su...@sujee.net> wrote:
>
> > HI All
> > the HBase book by Lars warns it is not recommended to set heap size above
> > 16G, because of 'stop the world' GC.
> >
> > Does this still apply? Specially with 'concurrentGC' ?
> >
> > thanks
> > Sujee
> > http://sujee.net
> >
>
>
>
> --
> Mikael.S
>
Re: hbase heap size beyond 16G ?
Posted by Mikael Sitruk <mi...@gmail.com>.
Concurrent GC (a.k.a CMS) does not mean that there is no more pause. The
pauses are reduced to minimum but can still happen especially if the
concurrent thread will not finish their work under high pressure. The G1
collector in JDK 7.0 pretends to be a better collector than CMS, but i
presume tests will need to be done to validate this.
BTW the CMS collector is the one that is recommented in the book.
Mikael.S
On Tue, Nov 8, 2011 at 11:57 PM, Sujee Maniyam <su...@sujee.net> wrote:
> HI All
> the HBase book by Lars warns it is not recommended to set heap size above
> 16G, because of 'stop the world' GC.
>
> Does this still apply? Specially with 'concurrentGC' ?
>
> thanks
> Sujee
> http://sujee.net
>
--
Mikael.S