You should check out Terracotta. http://www.terracotta.org/ It does
shared cross-JVM memory management pretty seamlessly. It's open source.
Being the good REST programmer that I am :), I don't keep session state
on the server. But, if I had to do it, they have a really slick way to
manage shared memory across JVMs. I saw a demo of their stuff at a JUG
meeting once. They demoed a shared Swing TableModel. Very interesting
and exciting stuff.
Adam
Kyrre Kristiansen wrote:
Yes, you are right.
You really have two options for this,
1. Use the database. This might not be a good solution
for short-length, time-based session data.
2. Use some sort of cluster-sharing, eg memcached
(which is C++, but I believe there's a Java-version
for it as well), or other solutions.
3. Don't share sessions in the cluster, which means
that you have to route the same client to the same
server throughtout the session. This is usually done
by cookies from the load-balancer (yet more cookies).
There's a second way to make sure that the same
requests come to the same server, but it's based on
IP. Most large cooperations use NAT-style routing out,
so that the load-balancer will only see one IP for up
to thousands of users, which will give uneven load on
the servers. Avoid this balancing scheme like the
plague.
Regards,
Kyrre
--- Marc Portier <[EMAIL PROTECTED]> wrote:
Kyrre Kristiansen wrote:
simple round-robin of a cookie-less system. And,
if
you want to make quick, highly reliable services,
load
balancing is almost as king as cache...
Kyrre, thx for pointing me to this,
I read this as the intrinsic point that
'resource-state' should be
shared in the server-cluster in some way...
Anyway, thx all for your comments on the thread,
sorry for not finding
the time earlier to participate after starting it...
have to give it some time to sip through, now...
regards,
-marc=
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Kyrre Kristiansen
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