Re: Prevayler vs Terracotta

It would be nice to have some sort of Lazy Initialization, but you
would need random access on the journal, not just at load time.

And besides, if you were doing that, the project would be doing what
other cache projects are doing (such as HCache, infinispan or JBoss
Cache).

On Wed, Nov 11, 2009 at 2:27 PM, William Pietri <[email protected]> wrote:
> I wasn't speaking of Java serialization, but the more generic use of the
> term: turning data into a stream of bytes.
>
> No matter what approach you use, I/O bandwidth limits and the CPU cost of
> reading many GB of data rules out Prevayler for many uses. Databases may be
> much slower for each transaction, but on typical hardware, Prevayler's
> startup times are much worse for equivalent data sets.
>
> William
>
> Clebert Suconic wrote:
>
> Serialization sucks!
>
>
> Provide an alternate Marshalling API for users, and you will have a
> *much* better throughput.
>
>
>
>
> On Wed, Nov 11, 2009 at 1:38 PM, William Pietri <[email protected]> wrote:
>
>
> Ralph Johnson wrote:
>
> Prevayler does require you to hold all your objects in the JVM heap in
> RAM. If you cannot do that, as you know, you cannot use Prevayler.
>
>
> Do any of you have experience with 64 bit machines?  What is the
> biggest Prevayler database you've seen?
>
>
> A client, who does not use Prevayler but is using the hot-in-RAM approach,
> has been using 64-bit machines with large JVMs quite happily. I think their
> production machine had 16 GB of RAM, with talk of expansion.
>
> The problem with this approach, though, turns out to be read IO bandwidth
> and object deserialization. Their startup times are on the order of 30
> minutes.
>
> If anybody has interesting solutions (hardware or software) to the long
> startup time problem, I'd love to hear about them, as I think that's
> Prevayler's Achilles' Heel for scaling.
>
> William
>
>
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-- 
Clebert Suconic
http://www.jboss.org/developers/#ClebertSuconic
http://clebertsuconic.blogspot.com

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