geronimo-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Dave Colasurdo <>
Subject Re: Clustering Geronimo with Open Terracotta
Date Fri, 16 Feb 2007 16:32:27 GMT
Comments inline..

Orion Letizi wrote:
> This is very cool.  You beat me to it-- I was going to add a clustering 
> with geronimo to our wiki as well.
The more documentation the better.  Feel free to use any of the content 
  from the Geronimo Wiki in your article.  A few areas that could be 
explored a bit more in depth include:

- Details on tc-config.xml and defining which application objects are 
appropriate for inclusion in this file.
- Details on how to use a JVM other than the one installed with the 
Session Configurator
- EJB Clustering details (when the support is fully available)

> At the end of the page, you list a few open questions:
>> Investigate if there is a slimmed down Terracotta sessions download 
>> image that doesn't include the Session Configurator, JDK, samples, etc
>> Investigate if there is a slimmed down Terracotta sessions download 
>> image that doesn't includes only the Terracotta Client.
> Our next release will have only a single, monolithic kit.  The current 
> Terracotta Sessions kit actually does include the server, it's just 
> packaged up a bit differently.  The multiple kits were very confusing to 
> people, so we decided to collapse them all (DSO, Spring, and Sessions) 
> into a single kit.  As for a reduced kit that doesn't include 
> configurator, jdk, samples, etc.-- I'll cross-post this to tc-dev and 
> bring the subject up there.   

Seems that the Terracotta Installer could make the non-production stuff 
(Session Configurator, Samples, JDK, etc.) optionally selectable during 
the install process.  Also it may be interesting to consider separate 
installation options for Terracotta Server and Terracotta Client (if 
this provides any significant disk space savings).

>> Investigate if Open Terracotta plans to support the Jetty Web Container.
> Jetty support is currently in the works.  I personally really like Jetty.
Will add this to the FAQ. Please post back here when this available.

>> Investigate Sticky Session support.
> Not sure what you mean by this...

Tomcat and Mod-jk provide the ability to have the load balancer lock a 
particular httpsession (identified by session cookie) to a specific 
cluster member.  This cluster member will serve all the requests for 
this session until the cluster member tops/fails and failover to a new 
cluster member  occurs.  This "stickiness" is quite useful for the case 
of multi-frame JSPs where it is important that all concurrent requests 
are executing in the same JVM (as per Java EE  specifications).  Hmmm, 
now that Terracotta provides the concept of a global cross-node JVM, I'm 
wondering how important this is now .. though still seems there would be 
  performance overhead in locking across JVMs.. so I think Sticky 
Session is still useful..

Anyway, I suspect the following two snippets are involved though haven't 
gotten them to work with Geronimo and Terracotta yet..

<gbean name="TomcatEngine">
<attribute name="initParams">name=Geronimo jvmRoute=nodeXYZ</attribute>

<reference name="Valve1">

Any thoughts??  Jeff?? Filip??

>> Investigate when Open Terracotta will support EJB clustering for 
>> Geronimo.
> EJB clustering is also in the works.  Tim Eck (one of our developers) 
> and Jeff Genender were working on EJB clustering a couple of weeks ago.  
> They got prototype EJB clustering working.  Not sure of the current status.

Ok, will check with Tim and Jeff..


>> Investigate when Open Terracotta will support the IBM JDK.
> We're planning on doing IBM JDK support soon, although I'm not sure if 
> it's been slated for a specific release yet.  My guess is sometime in 
> the first half of this year-- but, that's just a guess.
> Cheers,
> Orion
>> I've added an article to the Geronimo wiki that describes how to cluster
>> Geronimo HTTP Session web application data using the Open Terracotta
>> project.
>> Feel free to get it a try..

View raw message