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Hi Kirk,<br>
<br>
I'm CC'ing serviceability on this since this is really their JEP and
discussions around it should go on the serviceability list, even
though it seems you are mainly interested in GC logging at this
point.<br>
<br>
I understand what you want and I see that the logging level won't
help us get there. I don't agree that the logging we have today
can't fit nicely into a hierarchical scheme though, it just needs to
be more fine grained to achieve what you want.<br>
<br>
We can be pretty generous with modules and in principal have one
module for each verbose flag that exists today. Personally I don't
think that is a good idea, but it certainly is possible. I would
rather like to propose a different solution.<br>
<br>
How about we have a gc module that can be filtered based on
different sub modules. The sub modules could be fairly close to the
existing verbose flags that exists today if that turns out to be a
good way to divide information. It could look like this<br>
<br>
-Xverbose:gc=info,gc.tenuring=debug<br>
<br>
to set regular gc verbose to info level (I would say that is close
to PrintGC) and turn on more detailed logging for tenuring. Or<br>
<br>
-Xverbose:gc.tenuring<br>
<br>
that could be equal to what that flag prints today. Let's see what
the serviceability team thinks since they are the ones who will
actually implement this in the end.<br>
<br>
Another solution that I don't really like but guess is easier to
implement is to add the current verbose flag to the actual message
so that the logs can be filtered based on that. But this will
clutter the messages and we would still have the problem to decide
on which level things should get logged.<br>
/Jesper<br>
<br>
<br>
On 2012-06-20 07:28, Kirk Pepperdine wrote:
<blockquote
cite="mid:1BC2C076-7066-406A-87B2-A6F4618B7ECC@kodewerk.com"
type="cite">Hi Jesper,
<div><br>
</div>
<div>I did read the spec and I do like the ability to specify the
"component" that you'd like to log information from. So I feel
that is a great improvement over the (broken) pattern
established in every major logging Java framework. I'm going to
stick to GC logging just because I've spent so much time
puzzling over them and adjusting my parser to deal with all the
changes that have continuously crept into them. While 'm
certainly not going to argue for keeping the current GC logging
framework what I will say is that it's not all bad in that the
flags that have been provided to me are almost always
semantically meaningful in that they tell me what I'm going to
see. In this spirit I'd like to see a category like
TenuringDetails for example. Is this information INFO, DEBUG, or
TRACE? hard to say but it's clearly TenuringDetails and so this
is a subcategory that I'd like to define and it's clearly not a
subcategory that you'd want to define a generalize logging
framework. And it is here that this specification over-reaches.
It tries to define logging categories that are not only are
devoid of meaning, they assume a hierarchical structure to them.
Going back to GC logging I would argue that while there is some
hierarchy in there, most of the messages don't nicely fit into
this imposed hierarchical developer centric list of categories.</div>
<div><br>
</div>
<div>I think we could easily both agree that it would be
ridiculous for me to ask that you add PrintTunuring to the list
of levels yet that is exactly what I want. So I guess what I'm
asking is, what would the spec look like if you removed the log
levels from it and allowed me to define my own or to not even
use levels at all.</div>
<div><br>
</div>
<div>Regards,</div>
<div>Kirk</div>
<div><br>
</div>
<div>On 2012-06-20, at 1:03 AM, Jesper Wilhelmsson wrote:</div>
<div>
<div><br class="Apple-interchange-newline">
<blockquote type="cite">
<meta content="text/html; charset=ISO-8859-1"
http-equiv="Content-Type">
<div bgcolor="#FFFFFF" text="#000000"> Hi Kirk,<br>
<br>
To select what should be logged there should be logging
modules. A module could be for example class loading, gc,
jit compiler etc. The logging level is just a way to
control how much logging you want. Setting gc=info would
give you some basic gc logging while gc=debug would give
you more detailed info.<br>
<br>
A typical command line could look like<br>
<pre><code>
-Xverbose:gc=debug,finalizer=info,compiler,alloc,cookies=trace</code></pre>
/Jesper<br>
<br>
<br>
On 2012-06-19 23:44, Kirk Pepperdine wrote:
<blockquote
cite="mid:25BA359D-58E7-48F3-9575-E555A31FE3C2@kodewerk.com"
type="cite">Hi,
<div><br>
</div>
<div>I see the logging framework JEP finally was
published. This is great news.</div>
<div><br>
</div>
<div>I'd like to comment on this quality</div>
<div><br>
</div>
<div><span style="color: rgb(0, 0, 0); font-family:
'Bitstream Vera Sans', 'Luxi Sans', Verdana, Arial,
Helvetica; font-size: 14px; font-style: normal;
font-variant: normal; font-weight: normal;
letter-spacing: normal; line-height: 13px; orphans:
2; text-align: -webkit-auto; text-indent: 0px;
text-transform: none; white-space: normal; widows:
2; word-spacing: 0px; -webkit-text-size-adjust:
auto; -webkit-text-stroke-width: 0px; display:
inline !important; float: none; ">"Logging is
performed at different levels: error, warning, info,
debug, trace"</span></div>
<div><span style="color: rgb(0, 0, 0); font-family:
'Bitstream Vera Sans', 'Luxi Sans', Verdana, Arial,
Helvetica; font-size: 14px; font-style: normal;
font-variant: normal; font-weight: normal;
letter-spacing: normal; line-height: 13px; orphans:
2; text-align: -webkit-auto; text-indent: 0px;
text-transform: none; white-space: normal; widows:
2; word-spacing: 0px; -webkit-text-size-adjust:
auto; -webkit-text-stroke-width: 0px; display:
inline !important; float: none; "><br>
</span></div>
<div><span style="color: rgb(0, 0, 0); font-family:
'Bitstream Vera Sans', 'Luxi Sans', Verdana, Arial,
Helvetica; font-size: 14px; font-style: normal;
font-variant: normal; font-weight: normal;
letter-spacing: normal; line-height: 13px; orphans:
2; text-align: -webkit-auto; text-indent: 0px;
text-transform: none; white-space: normal; widows:
2; word-spacing: 0px; -webkit-text-size-adjust:
auto; -webkit-text-stroke-width: 0px; display:
inline !important; float: none; "><span
class="Apple-style-span" style="font-family:
Helvetica; line-height: normal; font-size: medium;
">If we accept the problems associated with level
based logging, these name work for generic
frameworks such as Log4J and JDK logging. However,
the names are meaningless in that they carry no
semantic context with what would be logged. The
nice thing about the current set of flags is they
convey the information that will be printed.</span></span></div>
<div><span style="color: rgb(0, 0, 0); font-family:
'Bitstream Vera Sans', 'Luxi Sans', Verdana, Arial,
Helvetica; font-size: 14px; font-style: normal;
font-variant: normal; font-weight: normal;
letter-spacing: normal; line-height: 13px; orphans:
2; text-align: -webkit-auto; text-indent: 0px;
text-transform: none; white-space: normal; widows:
2; word-spacing: 0px; -webkit-text-size-adjust:
auto; -webkit-text-stroke-width: 0px; display:
inline !important; float: none; "><span
class="Apple-style-span" style="font-family:
Helvetica; line-height: normal; font-size: medium;
"><br>
</span></span></div>
<div><span style="color: rgb(0, 0, 0); font-family:
'Bitstream Vera Sans', 'Luxi Sans', Verdana, Arial,
Helvetica; font-size: 14px; font-style: normal;
font-variant: normal; font-weight: normal;
letter-spacing: normal; line-height: 13px; orphans:
2; text-align: -webkit-auto; text-indent: 0px;
text-transform: none; white-space: normal; widows:
2; word-spacing: 0px; -webkit-text-size-adjust:
auto; -webkit-text-stroke-width: 0px; display:
inline !important; float: none; "><span
class="Apple-style-span" style="font-family:
Helvetica; line-height: normal; font-size: medium;
">On the question of log levels. I was hoping that
we would have learned from the follies of using
level based logging instead of a digital or tag
based system. IOWs a on or off different aspects
without having to eat the whole elephant of
records that some developer arbitrarily decided
should be dumped at a particular log level. One
can level tags.. but you can't get tags or digital
behaviour from levels.</span></span></div>
<div><span style="color: rgb(0, 0, 0); font-family:
'Bitstream Vera Sans', 'Luxi Sans', Verdana, Arial,
Helvetica; font-size: 14px; font-style: normal;
font-variant: normal; font-weight: normal;
letter-spacing: normal; line-height: 13px; orphans:
2; text-align: -webkit-auto; text-indent: 0px;
text-transform: none; white-space: normal; widows:
2; word-spacing: 0px; -webkit-text-size-adjust:
auto; -webkit-text-stroke-width: 0px; display:
inline !important; float: none; "><span
class="Apple-style-span" style="font-family:
Helvetica; line-height: normal; font-size: medium;
"><br>
</span></span></div>
<div><span style="color: rgb(0, 0, 0); font-family:
'Bitstream Vera Sans', 'Luxi Sans', Verdana, Arial,
Helvetica; font-size: 14px; font-style: normal;
font-variant: normal; font-weight: normal;
letter-spacing: normal; line-height: 13px; orphans:
2; text-align: -webkit-auto; text-indent: 0px;
text-transform: none; white-space: normal; widows:
2; word-spacing: 0px; -webkit-text-size-adjust:
auto; -webkit-text-stroke-width: 0px; display:
inline !important; float: none; "><span
class="Apple-style-span" style="font-family:
Helvetica; line-height: normal; font-size: medium;
">Kind regards,</span></span></div>
<div><span style="color: rgb(0, 0, 0); font-family:
'Bitstream Vera Sans', 'Luxi Sans', Verdana, Arial,
Helvetica; font-size: 14px; font-style: normal;
font-variant: normal; font-weight: normal;
letter-spacing: normal; line-height: 13px; orphans:
2; text-align: -webkit-auto; text-indent: 0px;
text-transform: none; white-space: normal; widows:
2; word-spacing: 0px; -webkit-text-size-adjust:
auto; -webkit-text-stroke-width: 0px; display:
inline !important; float: none; "><span
class="Apple-style-span" style="font-family:
Helvetica; line-height: normal; font-size: medium;
">Kirk Pepperdine</span></span></div>
</blockquote>
</div>
<span><jesper_wilhelmsson.vcf></span></blockquote>
</div>
<br>
</div>
</blockquote>
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