Re: JavaSpace Implementations

Hi,

Would all these objects have unique keys?

How large might an object get?

I'd have thought that a reasonable fit for what you're doing might be
one of the opensource JSR-107 caches......

Perhaps ehcache: http://ehcache.sourceforge.net/

Hope that helps,

Dan.

P.S.  I can think of several ways to build this on top of JavaSpaces but
I'm not aware of an out-of-the-box solution that's opensource.  There
might be something in newton (http://newton.codecauldron.org) you could
use but I'm not sure and it might be too "heavy" an option for your
intended use.

Sundaranathan wrote:
>
> Dan,
>
>    Here is my exact requirement.
>
>      I need a shared memory which stores a java object which will be
> accessed by applications running in 8 instances of weblogic. I don't
> want to have a single point of failure so i need the functionality of
> failover.  Also i need synchronization if there is more than one shared
> memory. Or can have  the shared object within weblogic instances. If one
> instance goes down then the object in memory should be replicated across
> instances as soon as possible.  To the maximum i may have couple of
> thousand entries to be precise today it is 5000 and may increase.
>
> I hope i answered your queries. Please let me know if you require more
> details.
>
> thanks,
> -Sundar.
>
> Dan Creswell wrote:
>> Hi,
>>
>> It would be useful if you could be more specific about your needs.
>> Failover and replication are simply features and there are a multitude
>> of ways to implement them and some approaches work better than others in
>> various scenarios.
>>
>> Further, depending on your exact needs, you may need to carefully select
>> a hardware configuration.
>>
>> So:
>>
>> (1)     What speed of failover do you require?
>>
>> (2)     Why do you need replication?  Presumably you don't want to
>> lose Entry's?
>>
>> (3)     How many Entry's do you plan to have in your JavaSpace at any
>> particular time?
>>
>> (4)     Are you using the JavaSpace for messaging or to hold state
>> long term
>> like an RDBMS?
>>
>> (5)     How many clients do you anticipate having connected to the
>> JavaSpace?
>>
>> Declaration:  I am the author of Blitz so I have my own biases!  I'm
>> also asking the above questions to try and understand what I would
>> implement were I to do it.
>>
>> I am not aware of an opensource implementation that addresses these
>> issues.  GigaSpaces does but, obviously, that's a commercial product
>> with associated cost models etc.
>>
>> Best wishes,
>>
>> Dan.
>>
>> Sundaranathan wrote:
>>> Hi All,
>>>
>>>     Can anyone please let me know, if there is any opensource JavaSpace
>>> implementation which has the functionality of FailOver and Replication.
>>> I went through Blitz site and found that failover and replication
>>> functionality has to be developed.
>>>
>>>
>>> thanks,
>>> -Sundar.
>>>
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