

Hazelcast - In-Memory Data Grid for Java  - vinutheraj
http://code.google.com/p/hazelcast/

======
jcdreads
Anyone with experience with both this and Oracle Coherence (formerly Tangosol
Coherence)? I'd dearly love for this to be a reasonable alternative to
Coherence, which I love but which is fabulously expensive.

------
drewr
This reminds me of Terracotta. Anyone care to contrast the two?

~~~
ShabbyDoo
Terracotta isn't peer-to-peer; it requires one or more management-ish servers.
However, it does offer persistence on those servers, so one could use
Terracotta in place of a database. Also, Terracotta works in the
(historically) Spring-like way of not requiring any modification to an
existing codebase. One declares which objects ought to be distributed, and
magic just happens (supposedly, I've only been reading up lately). Terracotta
does bytecode manipulation on those object references and on Java
synchronization blocks to achieve what is explicitly specified with this
system.

Another project to look into is JBoss's recently re-branded and improved
cache:

<http://www.jboss.org/infinispan>

I've been thinking about a problem lately that will likely require one of
these technologies, so I've been especially curious.

------
ShabbyDoo
I've always wanted to use such a technology to build a write-behind
persistence mechanism. Let's say that you want your data in a relational DB
(for reporting, company policy, integration, whatever) but can stand a very
small risk of losing a few seconds worth in the case of a huge failure. You'd
gain by avoiding the latency of network-to-db and disk forcing.

So, you write DAOs that "persist" to a queue and to a shared map(s). When you
read, you look in the map first and go to the DB upon failure. Queue consumers
persist messages (inserts/updates) to the db. After your application reaches a
steady state, you shouldn't have to read from the DB much at all. And, you
could build an eager loading mechanism for efficient start-up.

Even without async persistence, I'd prefer one of these solutions over
memcached/MySQL replication hackery.

~~~
far33d
Coherence (expensive) does this very well.

------
pohl
There might be enough here to build a distributed tulle space out of, like
GigaSpaces.

------
jokull
In Memory of Java

