hi all I have some questions to consult you about SCEA(Part-I) as follows,own thanks to you advance.
1.which are true about iterator pattern a. allows transverse of a data collection with different order b. allows different iterators to access a data collection simultaneously
I think a must be true,and not sure about b
2.a question about how to ensure ACID transaction for an entity EJB that access a legacy system
a. let the container to take care transaction b. let the entity EJB to monitor the transaction c. set the entity bean as Container Transaction Managed
I think b must be wrong,and not sure about a and c. I know the transaction for an entity EJB must be CMP, what's the difference between a and c,they all said the container managed the transaction .
3.a question about web server clustering
a. the load balancer holds the responsibility to maintain session data of web servers b. the load balancer need to route the request to the same web server for SSL connection
I think b is true,and not sure about a
4.What are the potential interference of firewall on IIOP a. port filtering b. address filtering c. load balancing d. Nework Address Translation (NAT) I think a and b is true,and not sure about c and d Best regards
Hi, I am new to SCEA and can't suggest you the answers. But if u will change the title of your question, you will get a better response. Title should be related to doubts. e.g. "Doubts : iterator pattern, ACID property, server clustering, firewall on IIOP." instead of "Can anyone give me the right answer and tell me why?" good luck.
Never mind the question title.. IMO 1) a 2) b ; if its legacy sys u cant trust the cntr to manage trnsc for u 3)b ; session replication comes in clustering and not in load balncr. 4)a,b,d; bcz often firewalls play as proxies too
Hi, I think the answers are the followings: 1) a, b -- You can have more than one Iterator per data collection simultaneously and have each iterator navigate the collection on different order. 2) a, c -- Both are the same. How the heck do you get an entity EJB to monitor the transaction ??? You can only do that in a stateful session bean. 3) b -- A load balancer does not hold session data. Note that it could also route the request to the same web server for non-SSL connection. 4) a, b, d -- The first two are obvious, but I think d could also influence the incoming IIOP request. If you disagree with these answers I'd love to hear your arguments against them. I'm not implying I'm right, in the contrary, I looking forward to learn something new.
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