Re: [Jdbm-general] Buffering Log File

[Kris L. <kl...@im...>]

Hi Rickard,

 >.. unless you use OOS.writeUnshared() which will not keep references.

Good point.  Had not tried that new 1.4+ feature.  I put it in and found
it does improve throughput by another 7% to 9%.  There is a noticable
reduction of CPU usage also.  Don't have good numbers but it is around
10% or more.  I implemented this change by replacing line #309
from:

        oos.writeObject(txns[curTxn]);

to:

        oos.writeUnshared(txns[curTxn]);

And removing Lines #315 to 317.

The only drawback to this change is that it requires JRE 1.4+.  For me,
it is just fine.  Don't know if that is acceptable for JDBM 0.20+ release.

Thanks,
Kris





Rickard Öberg wrote:

> Kris Leite wrote:
>
>>  >Not creating new streams all the time should improve it even more.
>>
>> Hmm, if you are implying that using the "reset()" of the 
>> ObjectOutputStream.
>> Then there was a slight improvement by replacing line #317:
>>        oos = new ObjectOutputStream(fos);
>> with:
>>       oos.reset();
>>
>> If you are suggesting removing it completely, that has a side effect
>> of GC not working since OOS/OIS keep references to the stored
>> object until the stream is closed or reset.
>
>
> .. unless you use OOS.writeUnshared() which will not keep references.
>
> /Rickard
>
>
>
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