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Static variable behavior in multi JVM env

Gajanan Gawhale
Greenhorn

Joined: Jun 26, 2010
Posts: 3
Hi,

I have defined a Map as a static variable and using it is as a cache. But when this map is getting updated the updated value is seen only in the JVM where it is updated.
What needs to be done to update the map value available on all the JVMs present on multiple nodes on multiple cells?

Thank you,
Ari
Jeanne Boyarsky
internet detective
Marshal

Joined: May 26, 2003
Posts: 30057
    
149

You could use a distributed caching library. Or treat the static variable as a read only cache so you don't have to worry about updates.


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Gajanan Gawhale
Greenhorn

Joined: Jun 26, 2010
Posts: 3
Jeanne Boyarsky wrote:You could use a distributed caching library. Or treat the static variable as a read only cache so you don't have to worry about updates.


Thanks for your quick reply. I need to update the cache as well so cannot make it read only. Is 'distributed caching library' available by default in WebSphere Server?
Jeanne Boyarsky
internet detective
Marshal

Joined: May 26, 2003
Posts: 30057
    
149

WebSphere offers Command Caching and Dynacache for a distributed cache. It is not on by default. And you have to use specific APIs rather than simply a static Map.
 
It is sorta covered in the JavaRanch Style Guide.
 
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