Re: Memory leaks
Re: Memory leaks
- Subject: Re: Memory leaks
- From: Art Isbell <email@hidden>
- Date: Tue, 19 Aug 2003 15:54:41 -1000
On Tuesday, August 19, 2003, at 03:27 PM, Robert Head wrote:
I'm working on a mission critical project to import records into our
DB, but finding that my WebObjects apps are getting (exponentially?)
slower and flakier with the size of the DB. We're only talking about
150k records (33.5 MB) so far, distributed primarily across 5 or 6
tables. The query times are still great outside of WebObjects (for
example, via phpmyadmin).
This sounds like the behavior of older EOF versions that held on to EO
snapshots for the life of the WO process such that if a great variety
of objects was being fetched, a higher and higher percentage of the
database records were being cached by the WO process causing process
memory to increase during the life of the process. This looked like a
memory leak, but references to these snapshots still existed, so it
wasn't a traditional memory leak.
This problem was eliminated by the implementation of snapshot
reference counting. As soon as the reference count of a snapshot
dropped to zero (no more references from objects in editing contexts),
the snapshot was available for garbage collection.
Even better memory management was introduced in WO 5.2. Objects in
editing contexts are available for garbage collection if no external
reference exists.
So if you're maintaining external references to lots of fetched
objects, these objects and their snapshots won't be garbage-collected
and memory usage will increase. This could be happening if session
time outs are very long such that many sessions continue to exist long
after the last request has been made.
If this were happening to me, I would check my code to ensure that I'm
destroying all unnecessary references to EO's as soon as possible. If
that didn't solve the problem, I'd consider licensing something like
Borland's OptimizeIt which includes automatic memory leak detection.
Aloha,
Art
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| | >Memory leaks (From: Robert Head <email@hidden>) |