+10000000000000
-dain
On Oct 28, 2004, at 1:24 AM, Danny Angus wrote:
This is a bit of a rant, I know but...
One thing I would like to see Sun do, from the point of view of my
previous
role at work, would be to devote more effort to improving the
stability and
performance of the Hotspot VM on
all platforms.
From what I can see are a number of defects in the Hotspot VM that
seriously affect the capapacity of many server products to achieve high
uptimes and high throughputs. Is this experience borne out by anyone
else
here?
Could we see some clarification of the garbage collection and
optimisation
mechanisms? It seems to me that there are a very large number of poorly
documented options for garbage collection and optimisations which are
neither specification features nor implementation features, but are in
wide
use by many people who are struggling to maintain high levels of
service in
the real world in the face of defects and failure of the JVM to behave
as
documented.
One example is the permanent generation size, Sun tell us that
allocations
in the permanent generation will continue up to the maximum size of the
permanent space, at which point further allocations will be from the
tenured heap space.
Seems sensible so far.
However it appears that requests for permanent allocation trigger a
full
garbage collection when they cannot be satisfied in the permanent
generation, this leads to the JVM thrashing and effectively defeats the
notion that tenured space could be used as an overflow.
The fact that this was not documented is almost as serious because it
removes some of the imperative which might otherwise encourage us to
profile not only hepa usage but also permanent generation requirements.
d.
***********************************************************************
****
The information in this e-mail is confidential and for use by the
addressee(s) only. If you are not the intended recipient (or
responsible for delivery of the message to the intended recipient)
please notify us immediately on 0141 306 2050 and delete the message
from your computer. You may not copy or forward it or use or disclose
its contents to any other person. As Internet communications are
capable of data corruption Student Loans Company Limited does not
accept any responsibility for changes made to this message after it
was sent. For this reason it may be inappropriate to rely on advice or
opinions contained in an e-mail without obtaining written confirmation
of it. Neither Student Loans Company Limited or the sender accepts any
liability or responsibility for viruses as it is your responsibility
to scan attachments (if any). Opinions and views expressed in this
e-mail are those of the sender and may not reflect the opinions and
views of The Student Loans Company Limited.
This footnote also confirms that this email message has been swept for
the presence of computer viruses.
***********************************************************************
***
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
