Stupid question - Request scope vs Session scope

[Rick Beaver]

Hello All

Stupid question. Am I right in assuming that there is little difference in the amount of data transfered over the network for objects stored in request scope, accessed in a JSP, vs objects stored in Session scope accessed the same way?

The objects are just stored in the same way right? The reference client side to a request attribute and a session attribute is the same?

The reason for asking is that someone at work today stated they were moving a map of objects to session scope instead of accessing them through request attributes to reduce network traffic - am I missing something that I should know here?

Thanks

[Bear Bibeault]

Originally posted by Rick Beaver:
Am I right in assuming that there is little difference in the amount of data transfered over the network for objects stored in request scope, accessed in a JSP, vs objects stored in Session scope accessed the same way?

There is no difference because there is no data transferred over the network in either case. And zero is pertty close to zero. The variable scopes are completely server-side mechanisms.

The objects are just stored in the same way right? The reference client side to a request attribute and a session attribute is the same?

There is no client-side reference to either.

The reason for asking is that someone at work today stated they were moving a map of objects to session scope instead of accessing them through request attributes to reduce network traffic - am I missing something that I should know here?

He's confused and making a major blunder if he's moving data to session scope for any reason other than making it available across multiple requests. He's probably just creating a memory leak.
[ April 13, 2006: Message edited by: Bear Bibeault ]

[Rick Beaver]

Thanks Bear, I didn't want to correct the chap because I started to doubt myself when he said that...

[Paul Clapham]

Actually it's possible that if you put an object into session scope, the container might serialize it to a database (if you configured persistent sessions into the container). And your database might well be on a different machine. So that would actually INCREASE the network traffic, rather than decreasing it.

[Ben Souther]

Originally posted by Paul Clapham:
Actually it's possible that if you put an object into session scope, the container might serialize it to a database (if you configured persistent sessions into the container). And your database might well be on a different machine. So that would actually INCREASE the network traffic, rather than decreasing it.

In addition, if you're clustering your app servers with session replication.
Every change to the session object will result in it being serialized and synced with the sessions in the other nodes.