On Fri, Apr 12, 2013 at 3:29 PM, Ulrich <[email protected]> wrote:
> Retrieving data is completely sequential, no concurrent processing at all. I
> changed the code to session.logout() and session.connect() after every step,
> this didn't help.
> So the code works like this:
> while (String path : pathList) {
> Session session = ...
> Node currentNode = session.getNode(path);
> Node filenode = Node.getNode("jcr:content");
> Property jcrdata = filenode.getProperty("jcr:data");
> InputStream is = jcrdata.getBinary().getStream();
> is.close();
> session.logout();
> }
>
> To be honest, this is not the exact code; the logic is spread over two
> classes - but it shows the effective data flow.
> Nevertheless - the problem remains.
> But when I retry the whole sequence later on, I get the same result - this
> means the buffer has been cleared in the meantime.
>
> It looks as if there is a kind of garbage collector
yes, it's your jvm's garbage collector.
> , running asynchronously not fast enough for avoiding the error but being
> done after a while.
yes, that's expected behaviour. the jvm's garbage collection runs
async with a low priority (unless you're
running out of memory of course).
> I tried to track the storage space by 'df -vk' but couldn't see a problem
> here.
did you check inodes as well ('df -i /')?
as i already mentioned: reading a lot of binaries will create
a lot of temp files. those temp files will eventually be deleted
once the gc determines that they're not used anymore (see [1]).
but this can take some time, due to the async nature of java's gc.
an example:
assume you have 500mb free disk space.
now when you're reading 1k binaries from the repository, 1mb size each,
in a loop, you're likely going to see said exception.
and the exception's message, 'no space left on device', is pretty clear:
you're (temporarily) running out of disk space.
did you try forcing gc cycles during your processing?
[1]
http://jackrabbit.apache.org/api/2.0/org/apache/jackrabbit/util/TransientFileFactory.html
> On Monday (I'm not in office right now) I will insert a Thread.sleep(20000)
> to the workflow above to verify my theory.
>
> Best regards,
> Ulrich
>
>
>
>
>
> Am 12.04.2013 um 10:13 schrieb Stefan Guggisberg
> <[email protected]>:
>
>> On Fri, Apr 12, 2013 at 12:21 AM, Ulrich <[email protected]> wrote:
>>> While retrieving lots of data in a loop from several nt:file nodes I always
>>> get a "no space left on device"-exception. The code is:
>>> Node filenode = Node.getNode("jcr:content");
>>> Property jcrdata = filenode.getProperty("jcr:data");
>>> InputStream is = jcrdata.getBinary().getStream();
>>> It seems that the InputStream is buffered somewhere for the current session
>>> and that the total buffer size for a session is limited. Is this true and
>>> if so, how can I control this size? Or is there an opportunity to free the
>>> space? I can probably close my session and open a new one but I would need
>>> to change the logic of my program,
>>>
>>> Any hint is very welcome.
>>
>> larger binaries are buffered in temp files on read (smaller ones are
>> buffered in-mem).
>> therefore, reading a lot of binaries concurrently will result in a lot
>> of temp files.
>> those temp files will go away once they're not referenced anymore.
>> your obviously running out of disk space.
>>
>> the following should help:
>>
>> 1. make sure you close the input stream as early as possible
>> 2. if this is a specific job you're running (such as e.g. an export) you
>> could
>> try forcing gc cycles in between
>> 3. increase your disk space
>>
>> cheers
>> stefan
>>
>>>
>>> Ulrich
