Oracle RAC Concept - load balancing

Hello All,
I have a question about Oracle RAC and how it balance loading.
What I know about Oracle RAC that it balancing load between its node, so if a new session is connected to the Database it will execute on the node which have less load.
If I am having an application that connects to the database with few number of sessions and some sessions have huge (huge load) processes to execute while the other sessions are executing small process (in terms of load).
So below is an example scenario that i am asking for an answer of it:
if am having a two node RAC database.
My application that is connected to this RAC database wants to execute three processes P1, P2 and P3 each will have a session correspondingly S1, S2 and S3
Let is say that P1 will take 60% of the database resources (memory ....) and P2 will take 1% and P3 1%.
So my question is it a sessions load balancing or Processes load balancing ? So in case and randomly (Managed by ORACLE RAC) S1 is connected to node 1 and it is using node 1 resources so the load on node 1 will be 60%, so when S2 and S3 needs to connect it will go to node 2 since node 1 is loaded. in that case i will have Node 1 using 60% of it is resources (becuase of S1 that is executing P1) while node 2 only uses 2 % (because of S2 and S3 that is executing P2 and P3).
Is that how Oracle RAC works ? or it balance the load of S1 (60%) between node 1 and node 2 ?
I am asking this question since my application is not users application, so it will connect to the database with few number of sessions, and 1 session of them may execute a huge process while the other are executing small processes.
So in that case, how RAC is doing the balance loading?
Regards,

i hope , this links may help you.
Thread: Server side Load balancing in RAC
Server Side Load Balancing Testing
read Oracle documentation:
http://www.oracle.com/pls/db102/search?word=server+side+load+balancing&partno=
http://www.oracleracexpert.com/2010/01/oracle-rac-load-balancing-and-failover.html
http://www.databasejournal.com/features/oracle/article.php/3659411/Oracle-RAC-Administration---Part-15-Connection-Load-Balancing-and-FAN.htm
http://oracleinstance.blogspot.com/2010/08/transparent-application-failover-taf.html

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Message was edited by:
user582458

<<
We understand that the solution is to use Web Cache on a dedicated separate server, to load balance the Portal servers. Can you please confirm that, or is collocation possible to avoid the cost of the dedicated Web Cache server
>>
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4joey1 wrote:
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===========
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can not open url
can not open url
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--The configuration of load balancing will be correct I think, have worked before
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--What can be wrong?
--Need help, what to check?
Services
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