You are viewing a plain text version of this content. The canonical link for it is here.
Posted to users@tomcat.apache.org by Randhir Singh <ra...@sterlite.com> on 2014/05/03 14:36:12 UTC
RE: How to monitor performance of tomcat
Thanks a lot for your detailed reply.
The JAVA_OPTS variable in $CATALINA_HOME/bin/startup.sh has the value as:
JAVA_OPTS="$JAVA_OPTS -Xms1303m -Xmx1303m -XX:MaxPermSize=256m
-Dcwom.bl.ip=127.0.0.1
-Dcwom.bl.port=1399"
I checked for free space on the VM instance with Red Hat Linux as the OS on
which the Tomcat is hosted with a total memory of 19 GB, I found that there
is around 8 GB of free space in the server.
As per your inputs, I am planning to increase the memory allocation for Heap
size and PermGen size to almost double as below:
JAVA_OPTS="$JAVA_OPTS -Xms2048m -Xmx2048m -XX:MaxPermSize=512m
-Dcwom.bl.ip=127.0.0.1
-Dcwom.bl.port=1399"
I hope, this should avoid the hang-up issues where Tomcat does not seem to
respond.
I plan to implement this in the UAT environment at first and see how it
goes.
Regards
-----Original Message-----
From: Jeffrey Janner [mailto:Jeffrey.Janner@PolyDyne.com]
Sent: Monday, April 28, 2014 7:39 PM
To: 'Randhir Singh'
Subject: RE: How to monitor performance of tomcat
> -----Original Message-----
> From: Randhir Singh [mailto:randhir.singh@sterlite.com]
> Sent: Monday, April 28, 2014 5:47 AM
> To: Jeffrey Janner; Tomcat Users List
> Subject: RE: How to monitor performance of tomcat
>
> Thanks for your valuable inputs. I am a bit of a novice to this. When
> this problem happens, it is quite a loss of face in front of the users
> who are widely spread geographically. I checked the catalina.out logs
> on the 2 days that the problem happened on 23rd & 25th April, the
> findings are as below:
>
> 23rd April '14:
>
> The catalina.out log showed the message like,
> ----------------------------------------------------------------------
> -
> ----------------------------------------------------------------------
> -
> ---------
> Caused by: org.jboss.remoting.InvocationFailureException: Socket timed
> out.
> Waited 300000 milliseconds for response while calling on
> InvokerLocator [socket://<hostname of our
> machine>:4173/?invokerDestructionDelay=5000&timeout=300000]; nested
> exception is:
> java.net.SocketTimeoutException: Read timed out
> ----------------------------------------------------------------------
> -
> ----------------------------------------------------------------------
> -
> ---------
>
> 3 times among other exceptions in a span of around 2 minutes.
>
> 25th April '14:
>
> The errors captured in the logs were like,
> ----------------------------------------------------------------------
> -
> ----------------------------------------------------------------------
> -
> ---------
> java.lang.OutOfMemoryError: GC overhead limit exceeded
This error specifically means that the JVM is basically spending all of its
time doing garbage collection and not really getting any significant amount
of memory back for its efforts. The end user experiences this usually as a
hung system. It might eventually come back or it might end up with a
different, more severe, OOM error.
There are lots of various causes for this: too small memory allocation; too
much load; an activity generating a lot of objects, most of which persist
for a long time; memory leaks; or a combination of the above.
How to address it?
a) Profile what parts of the app are being used with this occurs and have
the dev team look at what could be causing the problem. There might be a
better way to perform the action requested.
b) Increase the available memory (double it or more). This is only a
band-aid and you may still have the problem, but less often. Have the dev
team look for memory leaks.
c) Anyone else with ideas?
Jeff
> ----------------------------------------------------------------------
> -
> ----------------------------------------------------------------------
> -
> ---------
>
> 4 times among other exceptions in a span of around 2 minutes.
>
> Requesting a reply on this.
>
> Regards
__________________________________________________________________________
Confidentiality Notice: This Transmission (including any attachments) may
contain information that is privileged, confidential, and exempt from
disclosure under applicable law. If the reader of this message is not the
intended recipient you are hereby notified that any dissemination,
distribution, or copying of this communication is strictly prohibited.
If you have received this transmission in error, please immediately reply to
the sender or telephone (512) 343-9100 and delete this transmission from
your system.
--
*STL Disclaimer:*
The content of this message may be legally privileged and confidential and
are for the use of the intended recipient(s) only. It should not be read,
copied and used by anyone other than the intended recipient(s). If you have
received this message in error, please immediately notify the sender,
preserve its confidentiality and delete it. Before opening any attachments
please check them for viruses and defects. No employee or agent is
authorised to conclude any binding agreement on behalf of Sterlite
Technologies Limited with another party by email without express written
confirmation by authorised person. Visit us at www.sterlitetechnologies.com
Please consider environment before printing this email !
---------------------------------------------------------------------
To unsubscribe, e-mail: users-unsubscribe@tomcat.apache.org
For additional commands, e-mail: users-help@tomcat.apache.org
Re: How to monitor performance of tomcat
Posted by André Warnier <aw...@ice-sa.com>.
Randhir Singh wrote:
> Hi,
>
> I increased the Heap & PermGen memory as per trail mail but the performance
> seemed to deteriorate. On the day I increased the memory in the morning,
> the system hung 3 times in the day whereas the maximum times it has got
> hang before is 2 times in a day. I changed the memory settings for Heap &
> PermGen back to before when it hung again the next day, I reverted to the
> old memory values.
>
> The catalina.out showed the entries like below when I monitored it twice
> after the system hung with the new memory values:
>
> --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
>
> [ 22-May-2014 03:15:40 ] [ TRACE ] [http-30080-56] [ CHECK SESSION ] :
> Inside doInit Method
> May 22, 2014 3:16:14 PM org.zkoss.zk.ui.impl.UiEngineImpl handleError:1351
> SEVERE: >>org.zkoss.zk.ui.UiException:
> org.jboss.remoting.InvocationFailureException: Socket timed out. Waited
> 300000 milliseconds for response while calling on InvokerLocator [socket://
> bssossapp01.snl.com:4173/?invokerDestructionDelay=5000&timeout=300000];
> nested exception is:
> java.net.SocketTimeoutException: Read timed out
>>> org.jboss.remoting.InvocationFailureException: Socket timed out. Waited
> 300000 milliseconds for response while calling on InvokerLocator [socket://
> bssossapp01.snl.com:4173/?invokerDestructionDelay=5000&timeout=300000];
> nested exception is:
> java.net.SocketTimeoutException: Read timed out
>>> java.net.SocketTimeoutException: Read timed out
>>> at java.net.SocketInputStream.socketRead0(Native Method)
>
> --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
>
> I would be eager to respond in case of any clarification.
>
> Requesting a reply to resolve this as the attempt to resolve this by
> increasing Heap & PermGen memory has failed. I have worked on this issue a
> lot and have been trying to interact with the experts on the forum.
>
> Regards
>
Hi.
I am jumping in here in the middle, and have not followed the previous correspondence.
(Which is hard anyway, considering that you keep on top-posting).
(And I do not know Jboss at all, so maybe I am misinterpreting all of this).
But if I go by what you are mentioning above - and despite the apparent subject - it looks
to me as follows :
- the application (not part of any Tomcat code per se) is trying to connect to, and read
from, some (for Tomcat) external server
- and that external service is not responding, within the timeout set for this connection
(300,000 ms = 5 minutes)
- thus you see the above exceptions happening
So it is a bit hard from there, to figure out what the Tomcat Heap and Permgen sizes (or
Tomcat performance for that matter) have to do with this.
Intuitively, I would tend to think that if you give more memory to Tomcat to play with,
then maybe it tries to handle more simultaneous requests that cause more of these external
connections to be opened, all of them ultimately failing because the external server does
not respond.
Should you not look at what causes the external server to be slow to respond, first of all ?
---------------------------------------------------------------------
To unsubscribe, e-mail: users-unsubscribe@tomcat.apache.org
For additional commands, e-mail: users-help@tomcat.apache.org
Re: How to monitor performance of tomcat
Posted by Randhir Singh <ra...@sterlite.com>.
Hi,
I increased the Heap & PermGen memory as per trail mail but the performance
seemed to deteriorate. On the day I increased the memory in the morning,
the system hung 3 times in the day whereas the maximum times it has got
hang before is 2 times in a day. I changed the memory settings for Heap &
PermGen back to before when it hung again the next day, I reverted to the
old memory values.
The catalina.out showed the entries like below when I monitored it twice
after the system hung with the new memory values:
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
[ 22-May-2014 03:15:40 ] [ TRACE ] [http-30080-56] [ CHECK SESSION ] :
Inside doInit Method
May 22, 2014 3:16:14 PM org.zkoss.zk.ui.impl.UiEngineImpl handleError:1351
SEVERE: >>org.zkoss.zk.ui.UiException:
org.jboss.remoting.InvocationFailureException: Socket timed out. Waited
300000 milliseconds for response while calling on InvokerLocator [socket://
bssossapp01.snl.com:4173/?invokerDestructionDelay=5000&timeout=300000];
nested exception is:
java.net.SocketTimeoutException: Read timed out
>>org.jboss.remoting.InvocationFailureException: Socket timed out. Waited
300000 milliseconds for response while calling on InvokerLocator [socket://
bssossapp01.snl.com:4173/?invokerDestructionDelay=5000&timeout=300000];
nested exception is:
java.net.SocketTimeoutException: Read timed out
>>java.net.SocketTimeoutException: Read timed out
>> at java.net.SocketInputStream.socketRead0(Native Method)
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
I would be eager to respond in case of any clarification.
Requesting a reply to resolve this as the attempt to resolve this by
increasing Heap & PermGen memory has failed. I have worked on this issue a
lot and have been trying to interact with the experts on the forum.
Regards
On Wed, May 21, 2014 at 6:01 PM, Randhir Singh
<ra...@sterlite.com>wrote:
> Hi,
>
> There is a correction as JAVA_OPTS variable is defined in catalina.sh
> under $CATALINA_HOME/bin and we use $CATALINA_HOME/bin/startup.sh to start
> tomcat. $CATALINA_HOME/bin/startup.sh has the code like below ,
>
>
> ----------------------------------------------------------------------------------------------------------------------------------------------
> PRGDIR=`dirname "$PRG"`
> EXECUTABLE=catalina.sh
>
> # Check that target executable exists
> if $os400; then
> # -x will Only work on the os400 if the files are:
> # 1. owned by the user
> # 2. owned by the PRIMARY group of the user
> # this will not work if the user belongs in secondary groups
> eval
> else
> if [ ! -x "$PRGDIR"/"$EXECUTABLE" ]; then
> echo "Cannot find $PRGDIR/$EXECUTABLE"
> echo "The file is absent or does not have execute permission"
> echo "This file is needed to run this program"
> exit 1
> fi
> fi
>
> ----------------------------------------------------------------------------------------------------------------------------------------------
>
> I had changed catalina.sh in our development environment like a week back
> and want to implement it in the production environment but I got this
> doubt. I feel catalina.sh is invoked by startup.sh but am not sure. I have
> already taken downtime for production tomorrow but I got this doubt whether
> changing the
>
> JAVA_OPTS="$JAVA_OPTS -Xms1303m -Xmx1303m -XX:MaxPermSize=256m
> -Dcwom.bl.ip=127.0.0.1 -Dcwom.bl.port=1399" to
>
> JAVA_OPTS="$JAVA_OPTS -Xms2048m -Xmx2048m
> -XX:MaxPermSize=512m -Dcwom.bl.ip=127.0.0.1 -Dcwom.bl.port=1399"
>
> in catalina.sh would have the affect of increasing the heap & Permgen
> memory in Tomcat.
>
> I hope my query is clear as am quite anxious as I have a downtime
> scheduled tomorrow.
>
> Requesting a reply on priority.
>
>
> <ra...@sterlite.com> wrote:
>
>> Thanks a lot for your detailed reply.
>>
>> The JAVA_OPTS variable in $CATALINA_HOME/bin/startup.sh has the value as:
>>
>> JAVA_OPTS="$JAVA_OPTS -Xms1303m -Xmx1303m -XX:MaxPermSize=256m
>> -Dcwom.bl.ip=127.0.0.1
>> -Dcwom.bl.port=1399"
>>
>> I checked for free space on the VM instance with Red Hat Linux as the OS
>> on
>> which the Tomcat is hosted with a total memory of 19 GB, I found that
>> there
>> is around 8 GB of free space in the server.
>>
>> As per your inputs, I am planning to increase the memory allocation for
>> Heap
>> size and PermGen size to almost double as below:
>>
>> JAVA_OPTS="$JAVA_OPTS -Xms2048m -Xmx2048m -XX:MaxPermSize=512m
>> -Dcwom.bl.ip=127.0.0.1
>> -Dcwom.bl.port=1399"
>>
>> I hope, this should avoid the hang-up issues where Tomcat does not seem to
>> respond.
>>
>> I plan to implement this in the UAT environment at first and see how it
>> goes.
>>
>> Regards
>>
>> -----Original Message-----
>> From: Jeffrey Janner [mailto:Jeffrey.Janner@PolyDyne.com]
>> Sent: Monday, April 28, 2014 7:39 PM
>> To: 'Randhir Singh'
>> Subject: RE: How to monitor performance of tomcat
>>
>> > -----Original Message-----
>> > From: Randhir Singh [mailto:randhir.singh@sterlite.com]
>> > Sent: Monday, April 28, 2014 5:47 AM
>> > To: Jeffrey Janner; Tomcat Users List
>> > Subject: RE: How to monitor performance of tomcat
>> >
>> > Thanks for your valuable inputs. I am a bit of a novice to this. When
>> > this problem happens, it is quite a loss of face in front of the users
>> > who are widely spread geographically. I checked the catalina.out logs
>> > on the 2 days that the problem happened on 23rd & 25th April, the
>> > findings are as below:
>> >
>> > 23rd April '14:
>> >
>> > The catalina.out log showed the message like,
>> > ----------------------------------------------------------------------
>> > -
>> > ----------------------------------------------------------------------
>> > -
>> > ---------
>> > Caused by: org.jboss.remoting.InvocationFailureException: Socket timed
>> > out.
>> > Waited 300000 milliseconds for response while calling on
>> > InvokerLocator [socket://<hostname of our
>> > machine>:4173/?invokerDestructionDelay=5000&timeout=300000]; nested
>> > exception is:
>> > java.net.SocketTimeoutException: Read timed out
>> > ----------------------------------------------------------------------
>> > -
>> > ----------------------------------------------------------------------
>> > -
>> > ---------
>> >
>> > 3 times among other exceptions in a span of around 2 minutes.
>> >
>> > 25th April '14:
>> >
>> > The errors captured in the logs were like,
>> > ----------------------------------------------------------------------
>> > -
>> > ----------------------------------------------------------------------
>> > -
>> > ---------
>> > java.lang.OutOfMemoryError: GC overhead limit exceeded
>>
>> This error specifically means that the JVM is basically spending all of
>> its
>> time doing garbage collection and not really getting any significant
>> amount
>> of memory back for its efforts. The end user experiences this usually as
>> a
>> hung system. It might eventually come back or it might end up with a
>> different, more severe, OOM error.
>> There are lots of various causes for this: too small memory allocation;
>> too
>> much load; an activity generating a lot of objects, most of which persist
>> for a long time; memory leaks; or a combination of the above.
>> How to address it?
>> a) Profile what parts of the app are being used with this occurs and have
>> the dev team look at what could be causing the problem. There might be a
>> better way to perform the action requested.
>> b) Increase the available memory (double it or more). This is only a
>> band-aid and you may still have the problem, but less often. Have the dev
>> team look for memory leaks.
>> c) Anyone else with ideas?
>> Jeff
>>
>> > ----------------------------------------------------------------------
>> > -
>> > ----------------------------------------------------------------------
>> > -
>> > ---------
>> >
>> > 4 times among other exceptions in a span of around 2 minutes.
>> >
>> > Requesting a reply on this.
>> >
>> > Regards
>>
>> __________________________________________________________________________
>> Confidentiality Notice: This Transmission (including any attachments) may
>> contain information that is privileged, confidential, and exempt from
>> disclosure under applicable law. If the reader of this message is not the
>> intended recipient you are hereby notified that any dissemination,
>> distribution, or copying of this communication is strictly prohibited.
>>
>> If you have received this transmission in error, please immediately reply
>> to
>> the sender or telephone (512) 343-9100 and delete this transmission from
>> your system.
>>
>
>
--
*STL Disclaimer:*
The content of this message may be legally privileged and confidential and
are for the use of the intended recipient(s) only. It should not be read,
copied and used by anyone other than the intended recipient(s). If you have
received this message in error, please immediately notify the sender,
preserve its confidentiality and delete it. Before opening any attachments
please check them for viruses and defects. No employee or agent is
authorised to conclude any binding agreement on behalf of Sterlite
Technologies Limited with another party by email without express written
confirmation by authorised person. Visit us at www.sterlitetechnologies.com
Please consider environment before printing this email !
Re: How to monitor performance of tomcat
Posted by Randhir Singh <ra...@sterlite.com>.
Thanks Ognjen for your reply. My reply was intended to 2 different people
hence it repeated but anyway I would try to take care on this.
So now it is clear from your answer that catalina.sh is called from
startup.sh in a default installation.
Regards
On Thu, May 22, 2014 at 3:59 AM, Ognjen Blagojevic <
ognjen.d.blagojevic@gmail.com> wrote:
> Randhir,
>
> On 21.5.2014 14:31, Randhir Singh wrote:
>
>> I had changed catalina.sh in our development environment like a week back
>> and want to implement it in the production environment but I got this
>> doubt. I feel catalina.sh is invoked by startup.sh but am not sure. I have
>> already taken downtime for production tomorrow but I got this doubt
>> whether
>> changing the
>>
>
> 1. Don't post the same message twice. It makes volunteers on the list
> waste their time.
>
> 2. Don't top post. Bottom posting is the standard on this list.
>
> 3. Don't "request"/ People are volunteering here.
>
> 4. In default Tomcat instalation, catalina.sh is called from startup.sh.
>
> 5. Regardless of do you call startup.sh or catalina.sh, environment
> variables have the same meaning: JAVA_OPTS is used on Tomcat startup and
> Tomcat shutdown, while CATALINA_OPTS is only used on Tomcat startup. If you
> place -Xms2048m in JAVA_OPTS it will reserve 2 GB on Tomcat startup, and
> another 2 GB when you invoke Tomcat shutdown. That is waste of memory. Use
> CATALINA_OPTS instead.
>
> 6. It is not recommended to modify startup.sh or catalina.sh ever. All
> environment variables should be set in the file bin/setenv.sh.
>
> 7. (5.) and (6.) were already pointed out by Chris. Please read answers on
> the list carefully to show that you respect resources volunteers are
> allocating for you for free.
>
> 8. You may invoke "ps -fHA | grep Bootstrap" after you start Tomcat, to
> see if your CATALINA_OPTS reached JVM call.
>
> -Ognjen
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: users-unsubscribe@tomcat.apache.org
> For additional commands, e-mail: users-help@tomcat.apache.org
>
>
--
*STL Disclaimer:*
The content of this message may be legally privileged and confidential and
are for the use of the intended recipient(s) only. It should not be read,
copied and used by anyone other than the intended recipient(s). If you have
received this message in error, please immediately notify the sender,
preserve its confidentiality and delete it. Before opening any attachments
please check them for viruses and defects. No employee or agent is
authorised to conclude any binding agreement on behalf of Sterlite
Technologies Limited with another party by email without express written
confirmation by authorised person. Visit us at www.sterlitetechnologies.com
Please consider environment before printing this email !
Re: How to monitor performance of tomcat
Posted by Ognjen Blagojevic <og...@gmail.com>.
Randhir,
On 21.5.2014 14:31, Randhir Singh wrote:
> I had changed catalina.sh in our development environment like a week back
> and want to implement it in the production environment but I got this
> doubt. I feel catalina.sh is invoked by startup.sh but am not sure. I have
> already taken downtime for production tomorrow but I got this doubt whether
> changing the
1. Don't post the same message twice. It makes volunteers on the list
waste their time.
2. Don't top post. Bottom posting is the standard on this list.
3. Don't "request"/ People are volunteering here.
4. In default Tomcat instalation, catalina.sh is called from startup.sh.
5. Regardless of do you call startup.sh or catalina.sh, environment
variables have the same meaning: JAVA_OPTS is used on Tomcat startup and
Tomcat shutdown, while CATALINA_OPTS is only used on Tomcat startup. If
you place -Xms2048m in JAVA_OPTS it will reserve 2 GB on Tomcat startup,
and another 2 GB when you invoke Tomcat shutdown. That is waste of
memory. Use CATALINA_OPTS instead.
6. It is not recommended to modify startup.sh or catalina.sh ever. All
environment variables should be set in the file bin/setenv.sh.
7. (5.) and (6.) were already pointed out by Chris. Please read answers
on the list carefully to show that you respect resources volunteers are
allocating for you for free.
8. You may invoke "ps -fHA | grep Bootstrap" after you start Tomcat, to
see if your CATALINA_OPTS reached JVM call.
-Ognjen
---------------------------------------------------------------------
To unsubscribe, e-mail: users-unsubscribe@tomcat.apache.org
For additional commands, e-mail: users-help@tomcat.apache.org
Re: How to monitor performance of tomcat
Posted by Randhir Singh <ra...@sterlite.com>.
Hi,
There is a correction as JAVA_OPTS variable is defined in catalina.sh under
$CATALINA_HOME/bin and we use $CATALINA_HOME/bin/startup.sh to start
tomcat. $CATALINA_HOME/bin/startup.sh has the code like below ,
----------------------------------------------------------------------------------------------------------------------------------------------
PRGDIR=`dirname "$PRG"`
EXECUTABLE=catalina.sh
# Check that target executable exists
if $os400; then
# -x will Only work on the os400 if the files are:
# 1. owned by the user
# 2. owned by the PRIMARY group of the user
# this will not work if the user belongs in secondary groups
eval
else
if [ ! -x "$PRGDIR"/"$EXECUTABLE" ]; then
echo "Cannot find $PRGDIR/$EXECUTABLE"
echo "The file is absent or does not have execute permission"
echo "This file is needed to run this program"
exit 1
fi
fi
----------------------------------------------------------------------------------------------------------------------------------------------
I had changed catalina.sh in our development environment like a week back
and want to implement it in the production environment but I got this
doubt. I feel catalina.sh is invoked by startup.sh but am not sure. I have
already taken downtime for production tomorrow but I got this doubt whether
changing the
JAVA_OPTS="$JAVA_OPTS -Xms1303m -Xmx1303m -XX:MaxPermSize=256m
-Dcwom.bl.ip=127.0.0.1 -Dcwom.bl.port=1399" to
JAVA_OPTS="$JAVA_OPTS -Xms2048m -Xmx2048m
-XX:MaxPermSize=512m -Dcwom.bl.ip=127.0.0.1 -Dcwom.bl.port=1399"
in catalina.sh would have the affect of increasing the heap & Permgen
memory in Tomcat.
I hope my query is clear as am quite anxious as I have a downtime scheduled
tomorrow.
Requesting a reply on priority.
<ra...@sterlite.com> wrote:
> Thanks a lot for your detailed reply.
>
> The JAVA_OPTS variable in $CATALINA_HOME/bin/startup.sh has the value as:
>
> JAVA_OPTS="$JAVA_OPTS -Xms1303m -Xmx1303m -XX:MaxPermSize=256m
> -Dcwom.bl.ip=127.0.0.1
> -Dcwom.bl.port=1399"
>
> I checked for free space on the VM instance with Red Hat Linux as the OS on
> which the Tomcat is hosted with a total memory of 19 GB, I found that there
> is around 8 GB of free space in the server.
>
> As per your inputs, I am planning to increase the memory allocation for
> Heap
> size and PermGen size to almost double as below:
>
> JAVA_OPTS="$JAVA_OPTS -Xms2048m -Xmx2048m -XX:MaxPermSize=512m
> -Dcwom.bl.ip=127.0.0.1
> -Dcwom.bl.port=1399"
>
> I hope, this should avoid the hang-up issues where Tomcat does not seem to
> respond.
>
> I plan to implement this in the UAT environment at first and see how it
> goes.
>
> Regards
>
> -----Original Message-----
> From: Jeffrey Janner [mailto:Jeffrey.Janner@PolyDyne.com]
> Sent: Monday, April 28, 2014 7:39 PM
> To: 'Randhir Singh'
> Subject: RE: How to monitor performance of tomcat
>
> > -----Original Message-----
> > From: Randhir Singh [mailto:randhir.singh@sterlite.com]
> > Sent: Monday, April 28, 2014 5:47 AM
> > To: Jeffrey Janner; Tomcat Users List
> > Subject: RE: How to monitor performance of tomcat
> >
> > Thanks for your valuable inputs. I am a bit of a novice to this. When
> > this problem happens, it is quite a loss of face in front of the users
> > who are widely spread geographically. I checked the catalina.out logs
> > on the 2 days that the problem happened on 23rd & 25th April, the
> > findings are as below:
> >
> > 23rd April '14:
> >
> > The catalina.out log showed the message like,
> > ----------------------------------------------------------------------
> > -
> > ----------------------------------------------------------------------
> > -
> > ---------
> > Caused by: org.jboss.remoting.InvocationFailureException: Socket timed
> > out.
> > Waited 300000 milliseconds for response while calling on
> > InvokerLocator [socket://<hostname of our
> > machine>:4173/?invokerDestructionDelay=5000&timeout=300000]; nested
> > exception is:
> > java.net.SocketTimeoutException: Read timed out
> > ----------------------------------------------------------------------
> > -
> > ----------------------------------------------------------------------
> > -
> > ---------
> >
> > 3 times among other exceptions in a span of around 2 minutes.
> >
> > 25th April '14:
> >
> > The errors captured in the logs were like,
> > ----------------------------------------------------------------------
> > -
> > ----------------------------------------------------------------------
> > -
> > ---------
> > java.lang.OutOfMemoryError: GC overhead limit exceeded
>
> This error specifically means that the JVM is basically spending all of its
> time doing garbage collection and not really getting any significant amount
> of memory back for its efforts. The end user experiences this usually as a
> hung system. It might eventually come back or it might end up with a
> different, more severe, OOM error.
> There are lots of various causes for this: too small memory allocation; too
> much load; an activity generating a lot of objects, most of which persist
> for a long time; memory leaks; or a combination of the above.
> How to address it?
> a) Profile what parts of the app are being used with this occurs and have
> the dev team look at what could be causing the problem. There might be a
> better way to perform the action requested.
> b) Increase the available memory (double it or more). This is only a
> band-aid and you may still have the problem, but less often. Have the dev
> team look for memory leaks.
> c) Anyone else with ideas?
> Jeff
>
> > ----------------------------------------------------------------------
> > -
> > ----------------------------------------------------------------------
> > -
> > ---------
> >
> > 4 times among other exceptions in a span of around 2 minutes.
> >
> > Requesting a reply on this.
> >
> > Regards
>
> __________________________________________________________________________
> Confidentiality Notice: This Transmission (including any attachments) may
> contain information that is privileged, confidential, and exempt from
> disclosure under applicable law. If the reader of this message is not the
> intended recipient you are hereby notified that any dissemination,
> distribution, or copying of this communication is strictly prohibited.
>
> If you have received this transmission in error, please immediately reply
> to
> the sender or telephone (512) 343-9100 and delete this transmission from
> your system.
>
--
*STL Disclaimer:*
The content of this message may be legally privileged and confidential and
are for the use of the intended recipient(s) only. It should not be read,
copied and used by anyone other than the intended recipient(s). If you have
received this message in error, please immediately notify the sender,
preserve its confidentiality and delete it. Before opening any attachments
please check them for viruses and defects. No employee or agent is
authorised to conclude any binding agreement on behalf of Sterlite
Technologies Limited with another party by email without express written
confirmation by authorised person. Visit us at www.sterlitetechnologies.com
Please consider environment before printing this email !