hi Stefan.
Yes I was able to make it rip through saving lots of simple nodes like that
no problem.
When I add more properties, it degrades a fair bit (probably not surprising
if I guess at how the data is being stored for each property).
Interestingly, when I use my own specific node type it slows down quite a
lot (and memory consumption goes up) then with nt:unstructured, yet with all
other properties being set in the same way. I had to bump up the memory
quite a lot to avoid OutOfMemoryException's.
In the end, when I batched things up, I was able to ramp up the number of
nodes to what I wanted to test. Performance was acceptable once it was
loaded up - it is definately the save() operations that are the most
expensive. It was just very very difficult to build up my test data without
killing memory.
Thanks everyone for your help, I have learned a lot about jackrabbit in the
meantime.
On 9/1/06, Stefan Guggisberg <[EMAIL PROTECTED]> wrote:
hi michael
i quickly ran a test which successfully added 20k child nodes to the same
parent (whether that's a useful content model is a different story...).
here's the code i used to test:
Node parent = root.addNode("foo", "nt:unstructured");
for (int i = 1; i <= 20000; i++) {
parent.addNode("bar");
if (i % 1000 == 0) {
root.save();
System.out.println("added 1000 child nodes; total=" + i);
}
}
note that save() is a relatively expensive operation; it therefore makes
sense
to batch multiple addNode etc calls (which are relatively inexpensive).
please provide a simple self-contained test case that reproduces the
behaviour
you're describing.
cheers
stefan
On 9/1/06, Michael Neale <[EMAIL PROTECTED]> wrote:
> 1:
> yeah I use JProfiler - top of the charts with a bullet was:
> org.apache.jackrabbit.util.WeakIdentityCollection$WeakRef (a ha ! that
would
> explain the performance slug when GC has to kick in late in the piece).
> followed by:
> org.apache.derby.impl.store.raw.data.StoredRecordHeader
> and of course a whole lot of byte[].
>
> I am using default everything (which means Derby) and no blobs
whatsoever
> (so all in the database).
>
> 2:
> If I logout, and use fresh everything, it seems to continue fine (ie
fast
> enough pace), but I haven't really pushed it where I wanted to get it
(10000
> Child nodes).
>
> Responding to Alexandru's email (hi alex, nice work on InfoQ if I
remember
> correctly ! I am a fan), it would seem that the Session keeps most in
> memory, which I can understand.
>
> I guess my problem is that I am trying to load up the system to test
really
> basically that it scales to the numbers that I know I need to scale to,
but
> I am having trouble getting the data in - bulk load wise. If I bump up
the
> memory, it certainly seems to hum along better, but if Session is
keeping a
> lot around, then this will have limits - there is no way to "clear" the
> session ?
>
> Perhaps I will explain what I am using JCR for (feel free to smack me
down
> if this is not what JCR and Jackrabbit are ever indended for):
> I am storing "atomic business rules" (which means each node is a small
> single business rule). The data on each node is very small. These nodes
are
> stored flat as child nodes under a top level node. To give structure
> (categorisation) for the users, I have references to these nodes all
over
> the place so people can navigate them all sorts of different ways (as
there
> is no one clear hierarchy at the time the rules are created). JCR gives
me
> most of what I need, but as these rule nodes can number in the
thousands
> (4000 is not uncommon for a reasonably complex business unit), then I
am
> worried that this just can't work.
>
> I have seen from past posts that people put nodes under different
parents
> (so there is no great number of child nodes) so that is one option, but
my
> gut feel is that its the WeakIdentityCollection: this well meaning code
> means that the GC has to due a huge amount of work at the worst possible
> time (when under stress). I am sure most of the time this is not an
issue.
>
> Any ideas/tips/gotchas for a newbie? I would really like to be confident
> that I can scale up enough (its modest) with JCR for this purpose.
>
> On 8/31/06, Nicolas <[EMAIL PROTECTED]> wrote:
> >
> > 2 more ideas:
> >
> > 1/ Did you try using a memory profiler so we can know what is wrong?
> >
> > 2/ What happens if you logout after say 100 updates?
> >
> >
> > a+
> > Nico
> > my blog! http://www.deviant-abstraction.net !!
> >
> >
>
>
