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From Alexey Goncharuk <alexey.goncha...@gmail.com>
Subject Re: Page Memory behavior with default memory policy
Date Mon, 17 Apr 2017 11:40:09 GMT
Agree, I will rename it if there are no objections.

2017-04-17 14:31 GMT+03:00 Vladimir Ozerov <vozerov@gridgain.com>:

> Guys,
>
> I see that we throw our own "OutOfMemoryException" in this case. I think we
> should rename it to "IgniteOufOfMemoryException" to avoid confusion with
> JDK's "OutOfMemoryError". E.g. I looked at some thread dumps recently and
> was pretty sure that there was real OOME, while in reality it was Ignite's
> exception.
>
> On Mon, Apr 17, 2017 at 12:42 PM, Sergey Chugunov <
> sergey.chugunov@gmail.com
> > wrote:
>
> > Hello Denis,
> >
> > There is a small piece of documentation in *MemoryConfiguration *class,
> > although I think it should be moved to *MemoryPolicyConfiguration *and
> > detailed a lot.
> >
> > I'm going to write some documentation soon about validation rules that
> are
> > applied to memory policies configuration (there are some restrictions
> about
> > reserved name, default memory policy name and so on). I'll let you know
> > when it is done.
> >
> > About your question: MemoryPolicy offheap regions were never supposed to
> be
> > expandable. If user uses default MemoryPolicy (which in fact doesn't have
> > any eviction algorithm configured) he/she will get OutOfMemory error when
> > default size is exhausted.
> >
> > This OOM behavior was left intentionally to be consistent with the
> previous
> > behavior as configuring some default eviction policy on default
> > MemoryPolicy may lead to data loss and it is better to communicate wrong
> > memory configuration to user even with OOM than silently drop some cached
> > values.
> >
> > Thanks,
> > Sergey.
> >
> > On Mon, Apr 17, 2017 at 12:01 AM, Denis Magda <dmagda@apache.org> wrote:
> >
> > > Guys,
> > >
> > > I’ve been working on the documentation for page memory [1]. The doc is
> > > still in progress and it will be more profound with code snippets and
> > > pictures int the end, so don’t pay to the fact that it mostly consists
> of
> > > dry text only.
> > >
> > > So, the question is different. Presently, javadoc part is useless (and
> > > will be written by me as well) and it’s not clear what’s the default
> > > behavior of the page memory that has only one memory policy (default)
> > that
> > > instantiates a single memory region. Looking at the code I see that the
> > > default police creates 1 GB region that should be expandable because
> the
> > > policy doesn’t define an eviction algorithm. It means that if my app
> goes
> > > beyond 1 GB then the page memory will take more memory from an OS. Is
> my
> > > understanding correct?
> > >
> > > [1] https://apacheignite.readme.io/docs/page-memory <
> > > https://apacheignite.readme.io/docs/page-memory>
> > >
> > > —
> > > Denis
> >
>

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