Caveat: Apparently I am not as well. :)
1.) I looked at the 65M issue. On my development box (OSX) I set it
to -Xms128m -Xmx128m (basically arbitrary). So when I went to the
remote hosting company, I purchase a similar amount.
a. However, we are doing *very* little work (lots of product fetches
and only a few product inserts and updates) and it runs out of memory
*very* fast which I *assume* means it is my code, but I don't know.
b. I am doing research and here is a "web recommendation" (for all
that is worth)
Whenever possible, Unidata recommends
-Xmx1500m for 32-bit systems, and -Xmx2048m --Xmx4096m for 64-bit
systems.
c. Since the host is 64-bit, I am wondering whether my assumptions
may be off for 64-bit systems.
2. DataContext: Sorry, but I am getting confused on this one. I am
using BaseContext.getThreadObjectContext() based on recommendations (I
converted all the old DataContext refs to BaseContext, but I don't
really understand it from reading the docs) and am *not* releasing it
at the end of session. Not quite sure of how to do this properly.
3. Don't know how to set the cache to retain N number of objects. I
experimented with
query.setPageSize(RowsPerPage);
query.setCacheStrategy(QueryCacheStrategy.SHARED_CACHE);
query.setCacheGroups("product", "ProductList");
This seemed to help quite a bit but I still eventually ran out of
memory. I recently removed *all* the SHARED_CACHE and it ran out of
memory very fast.
Thanks for your input
Joe
On Sep 16, 2009, at 2:25 PM, Mike Kienenberger wrote:
Caveat: I'm not really an expert on Cayenne memory management.
1) Are you allocating enough heap memory to the app server to start
with? I don't know what the default is these days, but in the old
days, an application by default only gets 64Mb of memory -- that's
pretty small.
2) Are you using a new DataContext per request? Or at least per
session?
3) I seem to remember that the cache strategy is configurable. Have
you configured a cache that only retains N number of objects for a
suitable value of N?
On Wed, Sep 16, 2009 at 2:11 PM, Joe Baldwin
<[email protected]> wrote:
Hi,
I have asked this question a number of ways but I still have a very
serious
problem with Cayenne-specific memory management configuration
associated
with Tomcat.
The problem with debugging is that given that I have very little
visibility
into the Cayenne memory management it is extremely difficult to
debug this
using conventional strategies. Also I am not requesting anything
from the
system that is terribly exceptional so I am attempting to use default
settings as much as possible.
My strategy is to ask the experts for a Cayenne configuration and
standard
memory management steps I should take to conform to the new Cayenne
memory
management design intentions.
Problem:
1. I have essentially a webstore, three tier design with Tomcat,
Cayenne and
MySQL.
2. When after only a few queries of products, tomcat freezes up and
reports
out of memory errors.
I have attempted to configure the caching strategy ask best as I can
understand from the docks but this only gets me a few more hours of
usage
before the out of memory errors. (I tried the SHARED_CACHE). The
NO_CACHE
strategy is worse.
I would appreciate a set of steps (aka a primer) that should handle a
website with a lot of fetches of hundreds of data objects (i.e.
products)
and very few updates.
Note: My gut feeling is that I am not properly managing the data
object
array properly and it is leaking memory.
I would appreciate any input, but I would first like to know what the
minimum require steps are for managing at data object result set
ArrayList
so as to properly cache and then properly free the memory after it
is no
longer needed.
Context: Tomcat, MySQL, Cayenne 3.0M6
Thanks,
Joe Baldwin
