Jndi and serializable objects

Question

Hi,
I am attempting to create a cache on the web server to store
frequently accessed reference data. I do so by running a series of
queries in a startup class. The data retrieved from the result set of
each query is stored in a custom class and bound to the server context.
My understanding is that when serializable objects are bound, they are
written to disk (so as not.to waste valuable Heap space I assume). As a
test I made the startup query return a large amount of data and I
expected to see the amount of free disk space decrease as the objects
were bound however I did not see this occurring. I examined the memory
usage of the java process with the NT task manager, and the memory usage
was increasing pretty dramatically as the query results were performed
and new objects created to store this data.
Based on these observations I assume that the objects I created and
bound are stored in the Java Heap and not written to disk. Would
Weblogic at some point write these to disk if memory became tight or is
my understanding that binding an object serializes it incorrect?
If it turns out that what I am attempting here consumes a lot of heap
space, I assume that server performance will suffer which is
unacceptable. Would using read-only entity beans be a better solution?
The container could manage this memory more effectively but it would
seem to add a lot of overhead for a simple read only data cache.
Thanks,
Steve Snodgrass

Answer 1

We never write jndi data to the disk. So if you add more objects your are
going to take up more heap space. You should be looking at other
alternatives to implement this.
-- Prasad
Steve Snodgrass wrote:
Hi,
I am attempting to create a cache on the web server to store
frequently accessed reference data. I do so by running a series of
queries in a startup class. The data retrieved from the result set of
each query is stored in a custom class and bound to the server context.
My understanding is that when serializable objects are bound, they are
written to disk (so as not.to waste valuable Heap space I assume). As a
test I made the startup query return a large amount of data and I
expected to see the amount of free disk space decrease as the objects
were bound however I did not see this occurring. I examined the memory
usage of the java process with the NT task manager, and the memory usage
was increasing pretty dramatically as the query results were performed
and new objects created to store this data.
Based on these observations I assume that the objects I created and
bound are stored in the Java Heap and not written to disk. Would
Weblogic at some point write these to disk if memory became tight or is
my understanding that binding an object serializes it incorrect?
If it turns out that what I am attempting here consumes a lot of heap
space, I assume that server performance will suffer which is
unacceptable. Would using read-only entity beans be a better solution?
The container could manage this memory more effectively but it would
seem to add a lot of overhead for a simple read only data cache.
Thanks,
Steve Snodgrass