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Posted to users@tomcat.apache.org by Harish S Rathod <ha...@gmail.com> on 2008/11/14 19:53:12 UTC
Question regarding Tomcat memory
Hi,
To make our tomcat heap size memory to 8 GB we have set the below=20
settings echo $CATALINA_OPTS -Xms8192M -Xmx8192M -Xss1024K=20
-XX:PermSize=3D64m -XX:MaxPermSize=3D256m -Dfile.encoding=3DCp1252 Please=20
suggest is this ok ? as we are observing the maximum heap size memory for=20
tomcat gets a reduced bit to around 7756736K and it keeps flucatating. Is=
=20
this the normal behaviour?.
The OS we are using is Linux 8.
Re: Question regarding Tomcat memory
Posted by Christopher Schultz <ch...@christopherschultz.net>.
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Chuck,
Caldarale, Charles R wrote:
> I don't know how log4j determines that value
AFAIK, Log4j doesn't have any memory-specific memory info logging. The
user has to do it themselves. I suspect they are simply using
System.getRuntime() and then printing values from there.
- -chris
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RE: Question regarding Tomcat memory
Posted by "Caldarale, Charles R" <Ch...@unisys.com>.
> From: Harish S Rathod [mailto:harishjss2002@gmail.com]
> Subject: Re: Question regarding Tomcat memory
>
> -Xms8192M -Xmx8192M -Xss1024K -XX:PermSize=64m -XX:MaxPermSize=256m
> -Dfile.encoding=Cp1252
That's what I surmised.
> Please suggest is this ok ?
As long as you have the RAM to hold that much heap (plus the other memory required by the process), it should be o.k. If you don't have at least 9 GB of RAM, you're going to be paging like mad, which will absolutely kill performance.
Again, setting -Xss is usually pointless. I would set PermSize to the same value as MaxPermSize, just to avoid unnecessary expansion and contraction of the PermGen.
> - Well we are using 64 bit JDK
Which one?
> - We are prinitng the heap mem using Log 4J utitiy in the
> apllication logs.
I don't know how log4j determines that value; what is shown by JConsole or LambdaProbe? (The latter can be found at www.lambdaprobe.org.)
- Chuck
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Re: Question regarding Tomcat memory
Posted by Harish S Rathod <ha...@gmail.com>.
Hi,
Sorry the content of the mail was bit messed up ,i have corrected the
settings wordings please read the below text
To make our tomcat heap size memory to 8 GB we have set the below
settings
-Xms8192M -Xmx8192M -Xss1024K -XX:PermSize=64m -XX:MaxPermSize=256m
-Dfile.encoding=Cp1252
Please suggest is this ok ? as we are observing the maximum heap size memory
for
tomcat gets a reduced bit to around 7756736K and it keeps flucatating.Is
this normal behaviour
The OS we are using is Linux 8.
- Well we are using 64 bit JDK
- We are prinitng the heap mem using Log 4J utitiy in the apllication logs.
On Sat, Nov 15, 2008 at 4:01 AM, Caldarale, Charles R <
Chuck.Caldarale@unisys.com> wrote:
> > From: Harish S Rathod [mailto:harishjss2002@gmail.com]
> > Subject: Question regarding Tomcat memory
>
> First, use a different mailer or send only in plain text; whatever you're
> using is encoding even standard ASCII characters like "=".
>
> > To make our tomcat heap size memory to 8 GB we have set the below=20
>
> How much RAM and swap space do you have on the system? What JVM are you
> using? To go over 1.8 GB you need a 64-bit JVM.
>
> > $CATALINA_OPTS -Xms8192M -Xmx8192M -Xss1024K=20
>
> Setting -Xss is usually not useful, unless your application is very, very
> strange.
>
> > as we are observing the maximum heap size memory for
> > tomcat gets a reduced bit to around 7756736K and it
> > keeps flucatating.
>
> What are you using to do the "observing"? When I run JConsole targeting a
> JVM with the exact settings you specify, it says this about the heap:
>
> Committed: 8,039,104 kbytes
> Max: 8,039,104 kbytes
>
> This is on a SuSE 10 system, with JDK 1.6.0_07, in server mode.
>
> - Chuck
>
>
> THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY
> MATERIAL and is thus for use only by the intended recipient. If you received
> this in error, please contact the sender and delete the e-mail and its
> attachments from all computers.
>
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>
>
RE: Question regarding Tomcat memory
Posted by "Caldarale, Charles R" <Ch...@unisys.com>.
> From: Harish S Rathod [mailto:harishjss2002@gmail.com]
> Subject: Question regarding Tomcat memory
First, use a different mailer or send only in plain text; whatever you're using is encoding even standard ASCII characters like "=".
> To make our tomcat heap size memory to 8 GB we have set the below=20
How much RAM and swap space do you have on the system? What JVM are you using? To go over 1.8 GB you need a 64-bit JVM.
> $CATALINA_OPTS -Xms8192M -Xmx8192M -Xss1024K=20
Setting -Xss is usually not useful, unless your application is very, very strange.
> as we are observing the maximum heap size memory for
> tomcat gets a reduced bit to around 7756736K and it
> keeps flucatating.
What are you using to do the "observing"? When I run JConsole targeting a JVM with the exact settings you specify, it says this about the heap:
Committed: 8,039,104 kbytes
Max: 8,039,104 kbytes
This is on a SuSE 10 system, with JDK 1.6.0_07, in server mode.
- Chuck
THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY MATERIAL and is thus for use only by the intended recipient. If you received this in error, please contact the sender and delete the e-mail and its attachments from all computers.
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