tomcat clustering with Spring experiences

[dr_pompeii]

Dear Members

i am starting a project with Spring and i need your experience and knowledge

it seems and is an option work with cluster with tomcat 5.5.# series

this feature offer by tomcat is good, in performance, security etc etc?

any experiences in this topic, is really need it and appreciate

thanks in advanced

[Jörg Heinicke]

Before you even think about distributing your objects (which is what clustering means) you must consider the first law of distributed objects:

Don't distribute your objects.

The best scaling approach is always to have stateless services to which requests can be forwarded arbitrarily since no application state needs to be populated to every node in a cluster. You only need a load balancer selecting a server instance by servlet session so that a particular session is always handled by the same web server since that's application state you hardly can avoid in a web application. But with this approach the application (and the application server) is not even aware of multiple machines. They can be added arbitrarily, only the load balancer needs to be aware of them.

Second I heard some rumors about Terracotta.

Joerg

[dr_pompeii]

thanks so mcuh by the reply Jörg

The best scaling approach is always to have stateless services to which requests can be forwarded arbitrarily since no application state needs to be populated to every node in a cluster.

it sounds logic, so this would be for SWF a suicide

You only need a load balancer selecting a server instance by servlet session so that a particular session is always handled by the same web server since that's application state you hardly can avoid in a web application.

But with this approach the application (and the application server) is not even aware of multiple machines. They can be added arbitrarily, only the load balancer needs to be aware of them.

mmm

Second I heard some rumors about Terracotta.

me too, but it is a software, and i heard good rumors about it, but tomcat comes with this how feature.

tell me, which you use?

and i forgot to say ,that the term "clustering" in our reunion of work, appear only how an idea in the classic storm of ideas

tell me in which cases is nessary think or use clustering?

thanks again

best wishes

[Jörg Heinicke]

it sounds logic, so this would be for SWF a suicide

SWF means Spring Web Flow, doesn't it? So why should you not be able to use it?

me too, but it is a software, and i heard good rumors about it, but tomcat comes with this how feature.

Tomcat only provides session replication which I want to convince you is a bad idea. There are other layers that might be needed to be kept in sync, e.g. a Hibernate 2nd level cache. That's where Terracotta can help as far as I understand.

tell me, which you use?

None. We use the load balancer approach and my application doesn't have to care about it.

Joerg

[karldmoore]

SWF means Spring Web Flow, doesn't it? So why should you not be able to use it?

I would presume this might be related to sticky sesssions?

[Jörg Heinicke]

I would presume this might be related to sticky sesssions?

Our load balancer sends each request of a particular session to the same application server. That's a rather standard functionality as far as I know.

Joerg

[dr_pompeii]

hello guys

thanks both you for your replies

SWF means Spring Web Flow, doesn't it? So why should you not be able to use it?

answer

I would presume this might be related to sticky sesssions?

yes, and i dont know about the behaviour of the flowscope in clustering

Tomcat only provides session replication which I want to convince you is a bad idea.

ok,you advice is important, thanks

There are other layers that might be needed to be kept in sync, e.g. a Hibernate 2nd level cache. That's where Terracotta can help as far as I understand.

ok terracota seems a better solution than tomcat, ok

Our load balancer sends each request of a particular session to the same application server. That's a rather standard functionality as far as I know.

tell me
how did you do that?(bold part)
if you can share a link to learn this, i appreciate

regards

and thanks for your help

[nekoval]

how did you do that?(bold part)

some hardware devices support it on TCP level
and expensive ones - on HTTP level

as a low-cost solution you can try software LB, e.g. http://www.caucho.com/resin-3.0/conf...ance.xtp#resin

[Jörg Heinicke]

i dont know about the behaviour of the flowscope in clustering

How is it kept on the server-side? Not in the session?

Our load balancer sends each request of a particular session to the same application server.

how did you do that?

As I said I don't care about it - and I have no idea. The administrator set all this stuff up. That's the advantage: The application does not have to bother about the additional complexity and is scalable though.

Joerg

[dr_pompeii]

How is it kept on the server-side? Not in the session?

really i dont know in details, exists too flashscope

As I said I don't care about it - and I have no idea. The administrator set all this stuff up. That's the advantage:

auch