Le 4/5/12 12:43 AM, Selcuk AYA a écrit :
On Wed, Apr 4, 2012 at 3:22 PM, Emmanuel Lécharny<elecha...@gmail.com> wrote:
It's systematic, and I guess that the fact we now pond the RdnIndex table
way more often than before (just because we don't call anymore the
OneLevelIndex) cause the cache to get filled and not released fast enough.
do we hold a cursor open while this code gets stuck? I would think we
hold a cursor open and moduify quite a bit of jdbm btree pages for
this kind of behavior to happen.
I'll check that.
As we don't set any size for the cache, its default size is 1024. For some
of the tests, this mightnot be enough, as we load a lot of entries
(typically the schema elements) plus many others that get added and removed
while running tests in revert mode.
If I increase the default size to 65536, the tests are passing.
Ok, now, I have to admit I haven't - yet - looked at the LRUCache code, and
my analysis is just based on what I saw by quickly looking at the code, the
stack traces I have added and some few blind guesses.
However, I think we have a serious issue here. As far as I can tel, the code
itself is probably not responsible for this behaviour, but the way we use it
is.
Did I missed something ? Is there anything we can do - except increase the
cache size - to get the tests passing fine ?
I'm more concern about what could occur in real life, when some users will
load the server up to a point it just stop responding...
to aovid this issue, we can let the writers allocate more cache
pages(rather than keeping the cache size fixed) so that they do not
loop waiting for a replaceable cache. However, I would again suggest
making sure we do not forget the cursor open. If we forget a cursor
open and keep allocating new cache pages for writes, we will have
other problems.
Yeah, I can see how it may affect the tests. I'll definitively
investigate this first, before going any further in another direction.
ATM, I'm using a not committed version of JDBM were the default cache
size has been changed.
Thanks a lot Selcuk !
--
Regards,
Cordialement,
Emmanuel Lécharny
www.iktek.com
