I'm a little bit confused about your code. Some examples:

- after the execution of "baseXClient.execute(CLOSE)", baseXClient can
never be null; however, it may actually be null before the call of
execute()

baseXClient can be null because can happen an exception taking this from queue.

- what is hidden behind the CHECK and CLOSE variables?

private static final String CHECK = Commands.Cmd.CHECK + " %s";

private static final String OPEN = Commands.Cmd.OPEN + " %s";

At least for debugging purposes, I would recommend to create new
client instead of getting them from the pool. Your connection should
then be terminated via baseXClient.close().

For every call to method save() should I create a new BaseXClient?

Christian
___________________________

On Sun, Jun 24, 2012 at 4:47 PM, Willian Barcella <wbarcella@gmail.com> wrote:
> I close DB each insert, this is my code:
> ...
>     public void save(String key, DocumentWrapper value)
>     {
>         BaseXClient baseXClient = null;
>         try
>         {
>             //Open or Create database
>             baseXClient = this.takeConnection();
>             baseXClient.execute(format(CHECK, value.getCollectionName()));
>             InputStream is =
> XMLUtils.nodeToInputStream(value.getDocument());
>             baseXClient.replace(value.getId(), is);
>         } catch (Exception e)
>         {
>             throw new RuntimeException(e);
>         } finally
>         {
>             try
>             {
>                 baseXClient.execute(CLOSE);
>                 if (baseXClient != null)
>                     this.giveBack(baseXClient);
>             } catch (IOException e)
>             {
>                 logger.error("Error closing db", e);
>             }
>         }
>     }
> ...
>
> What you mean "single writer"?
>
>
> On Sun, Jun 24, 2012 at 11:38 AM, Dimitar Popov
> <dimitar.popov@uni-konstanz.de> wrote:
>>
>> check if you close the database after each insert operation. you should
>> also
>> know that currently, basex allows only a single writer, i.e. if you use
>> multiple threads just to insert of the documents faster, that won't
>> happen.
>>
>> regards,
>> dimitar
>>
>> On Sunday 24 June 2012 11:24:00 Willian Barcella wrote:
>> > There was an error in my code, I fixed it.
>> > Now I am not getting errors on client side, but BaseX is not persisting
>> > all
>> > documents that I inserted.
>> > I created 20 BaseXClient's, 10 threads to take BasXClient from a
>> > LinkedBlockingQueue, each thread was
>> > responsible to insert 1000 documents, total of documents 10 x 1000 =
>> > 10K,
>> > however was inserted 9801.
>> >
>> > Regards
>> >
>> > On Sun, Jun 24, 2012 at 10:48 AM, Christian Grün
>> >
>> > <christian.gruen@gmail.com>wrote:
>> > > Hi Willian,
>> > >
>> > > thanks for your mail. I would assume that one single BaseXClient
>> > > object was used for several concurrent tasks. As BaseXClient objects
>> > > are very light-weight, and as the registration of new clients is
>> > > usually more than fast enough, the usual approach is to create a new
>> > > BaseXClient instance for a dedicated action.
>> > >
>> > > Hope this helps,
>> > > Christian
>> > > _______________________________
>> > >
>> > > > I builded a kind of connection pool using BaseXClient.java class, I
>> > > > simulated several users trying insert documents in BaseX,
>> > > > the result was a disaster.
>> > > > ERROR: data.BaseXDataAccess - Error closing db
>> > > > java.io.IOException: Stopped at line 1, column 19:
>> > > > Unknown command: 1340477810253095000. Try HELP.
>> > > >
>> > > > at data.BaseXClient.execute(BaseXClient.java:99)
>> > > > at data.BaseXClient.execute(BaseXClient.java:110)
>> > > > at data.BaseXDataAccess.save(BaseXDataAccess.java:169)
>> > > > at data.TestInsert$Insert.run(TestInsert.java:88)
>> > > > at java.lang.Thread.run(Thread.java:680)
>> > > >
>> > > > Exception in thread "Thread-1" java.lang.RuntimeException:
>> > > >
>> > > > java.io.IOException:
>> > > > at data.BaseXDataAccess.save(BaseXDataAccess.java:164)
>> > > >
>> > > > at data.TestInsert$Insert.run(TestInsert.java:88)ERROR:
>> > > > com.xftec.hyperion.data.BaseXDataAccess - Error closing db
>> > > >
>> > > > I started several threads each one takes a BaseXClient connection
>> > > > and as
>> > > > soon as it finishs its job BaseXClient is put in a
>> > > > queue again to be took by other thread.
>> > > >
>> > > > _______________________________________________
>> > > > BaseX-Talk mailing list
>> > > > BaseX-Talk@mailman.uni-konstanz.de
>> > > > https://mailman.uni-konstanz.de/mailman/listinfo/basex-talk
>> _______________________________________________
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>
>
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