Max-beans-in-cache, transactions and passivation

Question

WLS 6.1 sp4
database concurrency, oracle
I compute max-beans-in-cache as:
(max # fetched in a transaction) * (number of worker threads)
therefore if I think that a table with have at most 500 rows and the
server is configured with 20 worker threads I have 500 * 20 = 10000 as
my max-beans-in-cache.
In my test the table has 7 rows. In our load test I see the Beans In
Use Count go up to 9999 instances and then start passivation.
I have two questions:
1) What does 'Beans In Use Count' really mean
2) why is weblogic using much more memory than it should to store 7 unique entities?
thanks

Answer 1

See my comments below.
S
Chad Urso McDaniel <[email protected]> wrote:
>
I understand this, but WebLogic should either reuse objects in the
cache/pool or not cache them at all. There are cases where the objects in the cahce are used. For e.g. with entity
beans and Read-Only concurrancy, when cache-between-tx is set. However I noticed
this behavior for other cases too and therefore the caching is not all that intellegent.
Also the beans in the pool are reused.
The current situation results in
objects being allocated, referenced by the cache so they will never be
garbage collected, but the objects are never used again once their
transaction completes. This is very, very wasteful with memory.
In some cases as mentioned above.
S
"Sri" <[email protected]> writes:
Hi,
The reason for having so many entries is due to fact that there isno way WLS
would know there are only 7 rows in the db everytime an entity beanis created/modified/accessed.
For e.g., if you run a test where you do 'findAll' the first run wouldhave 7
beans and the next most likely (There is another parameter that youcould use
to control number of beans in the cache, idle-timeout-seconds. Thoughits not
clear from the doc how the entity beans are handled wrt this parameter,it might
passivate entity beans if this timeout occurs) 14 and so on. If thisis a overhead
for your system then reduce this number.
S
container start removing beans before Chad Urso McDaniel <[email protected]>
wrote:
WLS 6.1 sp4
database concurrency, oracle
I compute max-beans-in-cache as:
(max # fetched in a transaction) * (number of worker threads)
therefore if I think that a table with have at most 500 rows and the
server is configured with 20 worker threads I have 500 * 20 = 10000as
my max-beans-in-cache.
In my test the table has 7 rows. In our load test I see the BeansIn
Use Count go up to 9999 instances and then start passivation.
I have two questions:
1) What does 'Beans In Use Count' really mean
2) why is weblogic using much more memory than it should to store7 unique
entities?
thanks