Each of the records has an primary key I guess. So build the uuid or any
hash from it and use it as key in a BTree structure. Simple and
straightforward.
Actually the idea is to find structure in your data. This is a core idea of
structured document stores. In case you have a large amount of siblings the
detail level of your structure might not be deep enough.
Anyway if you want to store key value tables somewhere there is a broad
pool of available open source solutions.
Cheers, D
On Saturday, 14 November 2015, Clay Ferguson <[email protected]> wrote:
Dirk,
What you're explaining would work great if the data had naturally
occurring
categories all being conveniently at whatever size JCR happens to handle
ok. This just doesn't work well in actuality. What if I just need to
store
a table of 25 million arbitrary records? The "it can't be done" with JCR
is
the honest answer. Solving it by creating a bunch of separate buckets is
a
massive ugly kluge. Whatever the technical limitation is, it's INSIDE
Jackrabbit, and badly needs to be addressed rather than forcing
developers
to jump thru hoops in application code. Surely I can't be the only one to
think this? Is everybody else just afraid to be critical like me, because
they are getting paid to work on JCR? Why don't we just be honest.
Best regards,
Clay Ferguson
[email protected] <javascript:;>
On Sat, Nov 14, 2015 at 2:35 AM, Dirk Rudolph <
[email protected]
<javascript:;>>
wrote:
I am planning on storing a lot of data in JackRabbit (terabytes)
But that should not mean storing them all as children of a single Node.
Probably you should think about driving the hierarchy as explained in
DavidsModel.
So in general you would structure your files in for example categories:
/categoryA
/categoryB
/categoryC
Or even
/categoryA/sub1/subsuba
/categoryA/sub1/subsubb
and so on. Each of them could then be a root of a NodeSequence managed
as
BTree. This would you additionally allow to split the content over
multiple
jackrabbit instances to increase performance.
In general Jackrabbit is/should be able to handle that many data but
maintanance might take a lot of time blocking your application. So you
should try to keep the repository size of a single instance as small as
possible by for example splitting content by category, region of
access,
or
what ever.
Or can I simplify it and just do something like this to get a repo
Have a look at:
https://jackrabbit.apache.org/api/2.10/org/apache/jackrabbit/commons/JcrUtils.html#getRepository(java.util.Map)
<
https://jackrabbit.apache.org/api/2.10/org/apache/jackrabbit/commons/JcrUtils.html#getRepository(java.util.Map)
The parameterMap contains for example
https://jackrabbit.apache.org/api/2.10/org/apache/jackrabbit/commons/JcrUtils.html#REPOSITORY_URI
<
https://jackrabbit.apache.org/api/2.10/org/apache/jackrabbit/commons/JcrUtils.html#REPOSITORY_URI
https://jackrabbit.apache.org/api/2.10/org/apache/jackrabbit/spi2davex/Spi2davexRepositoryServiceFactory.html#PARAM_REPOSITORY_URI
<
https://jackrabbit.apache.org/api/2.10/org/apache/jackrabbit/spi2davex/Spi2davexRepositoryServiceFactory.html#PARAM_REPOSITORY_URI
https://jackrabbit.apache.org/api/2.10/org/apache/jackrabbit/spi2davex/Spi2davexRepositoryServiceFactory.html#PARAM_ITEMINFO_CACHE_SIZE
<
https://jackrabbit.apache.org/api/2.10/org/apache/jackrabbit/spi2davex/Spi2davexRepositoryServiceFactory.html#PARAM_ITEMINFO_CACHE_SIZE
Btw. It should not be required to call ServiceLoader#load() by
yourself.
Cheers, D
Dirk Rudolph | Senior Software Engineer
Netcentric AG
M: +41 79 642 37 11
D: +49 174 966 84 34
[email protected] <javascript:;> <mailto:
[email protected] <javascript:;>> |
www.netcentric.biz <http://www.netcentric.biz/>
On 14 Nov 2015, at 01:26, David Marginian <[email protected]
<javascript:;>> wrote:
Thanks Dirk, I should have found that page on my own. I am going to
look into using the BTreeManager, just curious what are the limitations
for
documents/file counts within a node? I am planning on storing a lot of
data in JackRabbit (terabytes). Also, is the configuration code I
posted
in my previous posts the best way to do things? Or can I simplify it
and
just do something like this to get a repo:
ServiceLoader.load(Class.forName("org.apache.jackrabbit.jcr2dav.Jcr2davRepositoryFactory"));
return JcrUtils.getRepository(jackabbitServerUrl);
On 11/13/2015 03:47 PM, Dirk Rudolph wrote:
Did I understood you right, you have thousands of child nodes below
the
root node?
You should avoid this because this is considered bad practice in
terms
of
write performance and depending on your concurrent access this might
also
block read access.
http://wiki.apache.org/jackrabbit/Performance
Try to introduce a structure to your content using BTreeManger
https://jackrabbit.apache.org/api/2.10/org/apache/jackrabbit/commons/flat/BTreeManager.html
Cheers, D
On Friday, 13 November 2015, David Marginian <[email protected]
<javascript:;>>
wrote:
Thanks Clay. I am not trying to load that many records at once.
The
application is crawling a directory. It places the files from that
directory into JackRabbit one at a time, and puts a content id
onto a
queue
which is picked up by consumers on different servers. Those
consumers
then
use the content id to retrieve the file from JackRabbit. Each piece
of
content is saved in a node under the root node. The performance
slowdown
is coming from calling session.getRootNode(), from what I can
gather
from
the docs I need the root node in order to add a child node. Note
the
slowdown is pretty significant and I don't need to have close to
50k
to
start seeing it (I start seeing it within a few minutes of running
my
app). I don't need orderable nodes, how do I disable that?
On 11/13/2015 03:10 PM, Clay Ferguson wrote:
Please let us know more about your use case. Why are you even
"trying" to
load that many records all at once. Or at least scan them one by
one,
I
mean. In most use cases you wouldn't need to do this kind of
thing,
unless
it's some kind of backup or replication. I say "most" cases... I'm
not
saying you don't need to just asking for a bit more background.
BTW: If
you don't need 'orderable' nodes try to avoid them. That type of
node
does
not work at 'scale'... and 50K is propably pushing it.
Best regards,
Clay Ferguson
[email protected] <javascript:;>
On Fri, Nov 13, 2015 at 3:33 PM, <[email protected]
<javascript:;>> wrote:
Hi,
I am new to JackRabbit and using version 2.11.2. I am using
JackRabbit
to
store documents in a multi-threaded environment. I noticed that
the
time
it takes to retrieve the root node is inconsistent and slow
(several
seconds +) and degrades over time (after 50K plus child nodes
retrieval
is
taking ~15 seconds).
Originally, I was using code as follows to obtain a repository:
public Repository getRepository() throws
ClassNotFoundException,
RepositoryException {
ServiceLoader.load(Class.forName("org.apache.jackrabbit.jcr2dav.Jcr2davRepositoryFactory"));
return JcrUtils.getRepository(jackabbitServerUrl);
}
Then I came across the following thread:
http://jackrabbit.510166.n4.nabble.com/getRootNode-takes-27-seconds-td1571027.html#a1571302
This thread had some useful information (BatchReadConfig), but I
am
not
certain how to use the API to take advantage of it. I have
changed
my
code
to the following but it doesn't appear that node retrieval
performance
has
improved, is there something I am missing/doing wrong?
1) Repository Factory
public Repository getRepository(@SuppressWarnings("rawtypes") Map
parameters) throws RepositoryException {
String repositoryFactoryName = parameters != null && (
parameters.containsKey(PARAM_REPOSITORY_SERVICE_FACTORY) ||
parameters.containsKey(PARAM_REPOSITORY_CONFIG))
?
"org.apache.jackrabbit.jcr2spi.Jcr2spiRepositoryFactory"
:
"org.apache.jackrabbit.core.RepositoryFactoryImpl";
Object repositoryFactory;
try {
Class<?> repositoryFactoryClass =
Class.forName(repositoryFactoryName, true,
Thread.currentThread().getContextClassLoader());
repositoryFactory =
repositoryFactoryClass.newInstance();
}
catch (Exception e) {
throw new RepositoryException(e);
}
if (repositoryFactory instanceof RepositoryFactory) {
return ((RepositoryFactory)
repositoryFactory).getRepository(parameters);
}
else {
throw new RepositoryException(repositoryFactory + "
is
not a
RepositoryFactory");
}
}
2) Use the factory to get a repo:
public Repository getRepository() throws
ClassNotFoundException,
RepositoryException {
Map<String, RepositoryConfig> parameters =
Collections.singletonMap(
"org.apache.jackrabbit.jcr2spi.RepositoryConfig",
(RepositoryConfig) new
RepositoryConfigImpl(jackabbitServerUrl));
return getRepository(parameters);
}
3) Repository Config:
private static final class RepositoryConfigImpl implements
RepositoryConfig {
private String jackabbitServerUrl;
private RepositoryConfigImpl(String jackabbitServerUrl)
{
super();
this.jackabbitServerUrl = jackabbitServerUrl;
}
public CacheBehaviour getCacheBehaviour() {
return CacheBehaviour.INVALIDATE;
}
public int getItemCacheSize() {
return 100;
}
public int getPollTimeout() {
return 5000;
}
public RepositoryService getRepositoryService() throws
RepositoryException {
BatchReadConfig brc = new BatchReadConfig() {
public int getDepth(Path path, PathResolver
resolver)
throws NamespaceException {
return 1;
}
};
return new RepositoryServiceImpl(jackabbitServerUrl,
brc);
}
}
Thanks for your time.
David
--
Dirk Rudolph | Senior Software Engineer
Netcentric AG
M: +41 79 642 37 11
D: +49 174 966 84 34
[email protected] | www.netcentric.biz
