PrintGCStats
Ciciora, Paul
Ciciora at cboe.com
Mon Dec 3 20:25:33 UTC 2007
Since GC formats are constantly changing and different collectors log
stats differently I'd love to so you adopt a harvestable output format.
The idea would be to send stats to a separate file and use a name/value
style format. That way you could send whatever you wanted there and all
the harvester script or program would have to know is the tag name. The
name could be terse to save space. You could register the tag names so
open source changes would conform. If you did that then format changes
to the human readable output could be separate. You wouldn't have to be
as sensitive to breaking scripts.
Just a thought. I'm probably not the first one to suggest this.
-----Original Message-----
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Today's Topics:
1. PrintGCStats (Naas, Dave)
2. Re: PrintGCStats (Peter B. Kessler)
----------------------------------------------------------------------
Message: 1
Date: Mon, 3 Dec 2007 10:57:30 -0600
From: "Naas, Dave" <naasd at cboe.com>
Subject: PrintGCStats
To: <hotspot-gc-dev at openjdk.java.net>
Message-ID:
<4BD174404CF4A34C98322DC926CF862B2289F2 at MSMAIL.cboent.cboe.com>
Content-Type: text/plain; charset="iso-8859-1"
Regarding the posting from Oct 26, 2007:
http://mail.openjdk.java.net/pipermail/hotspot-gc-dev/2007-October/00006
4.html
where Mr. Kessler states:
quote
> > I'll see if we can get an updated version of PrintGCStats
out to replace the ancient one available at
> >
<http://java.sun.com/developer/technicalArticles/Programming/turbo/>
> > That should give you the kinds of statistics you are asking
for.
> > ... peter
unquote
I was wondering if a new version of PrintGCStats and PrintGCFixup will
indeed be made available or if we should proceed with our own updates to
handle new jdk releases, etc.??
A specific, recent example is jdk 1.6 with the -XX:PrintFLSStatistics
flag. We have found that this setting prevents the current PrintGCStats
from properly parsing ParNew data and thus doesn't generate the
Promotion stats (Promo.csv file). The following snippet shows how the
ParNew line is now split (shown in bold), thanks to the
-XX:PrintFLSStatistics:
========================================================================
========================================================================
======
{Heap before GC invocations=0 (full 0):
par new generation total 305088K, used 277376K [0x2f800000,
0x43d00000, 0x43d00000)
eden space 277376K, 100% used [0x2f800000, 0x406e0000, 0x406e0000)
from space 27712K, 0% used [0x406e0000, 0x406e0000, 0x421f0000)
to space 27712K, 0% used [0x421f0000, 0x421f0000, 0x43d00000)
concurrent mark-sweep generation total 2739200K, used 0K [0x43d00000,
0xeb000000, 0xeb000000)
concurrent-mark-sweep perm gen total 131072K, used 14913K [0xeb000000,
0xf3000000, 0xfb000000)
8.746: [GC Before GC:
Statistics for BinaryTreeDictionary:
------------------------------------
Total Free Space: 701235200
Max Chunk Size: 701235200
Number of Blocks: 1
Av. Block Size: 701235200
Tree Height: 1
Before GC:
Statistics for BinaryTreeDictionary:
------------------------------------
Total Free Space: 0
Max Chunk Size: 0
Number of Blocks: 0
Tree Height: 0
8.746: [ParNew
Desired survivor size 14188544 bytes, new threshold 1 (max 4)
- age 1: 15763640 bytes, 15763640 total
- age 2: 56 bytes, 15763696 total
: 277376K->15474K(305088K), 0.5657873 secs]
277376K->15474K(3044288K)After GC:
Statistics for BinaryTreeDictionary:
------------------------------------
Total Free Space: 701218816
Max Chunk Size: 701218816
Number of Blocks: 1
Av. Block Size: 701218816
Tree Height: 1
After GC:
Statistics for BinaryTreeDictionary:
------------------------------------
Total Free Space: 0
Max Chunk Size: 0
Number of Blocks: 0
Tree Height: 0
, 0.5668866 secs] [Times: user=0.34 sys=1.07, real=0.57 secs]
========================================================================
========================================================================
======
Thank you,
Dave
David Naas
Chicago Board Options Exchange
312-786-7222
------------------------------
Message: 2
Date: Mon, 03 Dec 2007 10:19:41 -0800
From: "Peter B. Kessler" <Peter.Kessler at Sun.COM>
Subject: Re: PrintGCStats
To: "Naas, Dave" <naasd at cboe.com>
Cc: hotspot-gc-dev at openjdk.java.net
Message-ID: <475448BD.3030401 at Sun.COM>
Content-Type: text/plain; format=flowed; charset=ISO-8859-1
It looks like the most recent PrintGCFixup (and PrintGCStats
and CompareGCStats) is "posted" in
http://permalink.gmane.org/gmane.comp.java.openjdk.hotspot.gc.devel/51
You have to join all the lines that got wrapped (sigh).
Sometimes you have to run PrintGCFixup more than once to
get it to remove things so that it can see other things
to remove. Though, in your case, running it twice doesn't
help remove the output of PrintFLSStatistics. It does look
like if you add a cleaner for PrintFLSStatistics, you'll
have to run PrintGCFixup at least twice, since that output
gets in the way of the removal of the PrintTenuringDistribution
flag.
PrintGCFixup and friends look like a prime candidate for putting
in hotspot/tools/ and letting people make improvements. If you
wanted to contribute your addition for removing PrintFLSStatistics,
I'm sure we could find someone here to sponsor it.
... peter
Naas, Dave wrote:
> Regarding the posting from Oct 26, 2007:
http://mail.openjdk.java.net/pipermail/hotspot-gc-dev/2007-October/00006
4.html
> where Mr. Kessler states:
> quote
> > > I'll see if we can get an updated version of PrintGCStats
out to replace the ancient one available at
> > >
<http://java.sun.com/developer/technicalArticles/Programming/turbo/>
> > > That should give you the kinds of statistics you are asking
for.
> > > ... peter
> unquote
>
> I was wondering if a new version of PrintGCStats and PrintGCFixup will
indeed be made available or if we should proceed with our own updates to
handle new jdk releases, etc.??
>
> A specific, recent example is jdk 1.6 with the -XX:PrintFLSStatistics
flag. We have found that this setting prevents the current PrintGCStats
from properly parsing ParNew data and thus doesn't generate the
Promotion stats (Promo.csv file). The following snippet shows how the
ParNew line is now split (shown in bold), thanks to the
-XX:PrintFLSStatistics:
>
>
========================================================================
========================================================================
======
> {Heap before GC invocations=0 (full 0):
> par new generation total 305088K, used 277376K [0x2f800000,
0x43d00000, 0x43d00000)
> eden space 277376K, 100% used [0x2f800000, 0x406e0000, 0x406e0000)
> from space 27712K, 0% used [0x406e0000, 0x406e0000, 0x421f0000)
> to space 27712K, 0% used [0x421f0000, 0x421f0000, 0x43d00000)
> concurrent mark-sweep generation total 2739200K, used 0K [0x43d00000,
0xeb000000, 0xeb000000)
> concurrent-mark-sweep perm gen total 131072K, used 14913K
[0xeb000000, 0xf3000000, 0xfb000000)
> 8.746: [GC Before GC:
> Statistics for BinaryTreeDictionary:
> ------------------------------------
> Total Free Space: 701235200
> Max Chunk Size: 701235200
> Number of Blocks: 1
> Av. Block Size: 701235200
> Tree Height: 1
> Before GC:
> Statistics for BinaryTreeDictionary:
> ------------------------------------
> Total Free Space: 0
> Max Chunk Size: 0
> Number of Blocks: 0
> Tree Height: 0
> 8.746: [ParNew
> Desired survivor size 14188544 bytes, new threshold 1 (max 4)
> - age 1: 15763640 bytes, 15763640 total
> - age 2: 56 bytes, 15763696 total
> : 277376K->15474K(305088K), 0.5657873 secs]
277376K->15474K(3044288K)After GC:
> Statistics for BinaryTreeDictionary:
> ------------------------------------
> Total Free Space: 701218816
> Max Chunk Size: 701218816
> Number of Blocks: 1
> Av. Block Size: 701218816
> Tree Height: 1
> After GC:
> Statistics for BinaryTreeDictionary:
> ------------------------------------
> Total Free Space: 0
> Max Chunk Size: 0
> Number of Blocks: 0
> Tree Height: 0
> , 0.5668866 secs] [Times: user=0.34 sys=1.07, real=0.57 secs]
>
========================================================================
========================================================================
======
>
> Thank you,
> Dave
>
> David Naas
> Chicago Board Options Exchange
> 312-786-7222
>
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