On 17.08.2017 11:21, Fady Haikal wrote:
Team,
Please i need some help her
Maybe start here ? http://lmgtfy.com/?q=analyse+tomcat+heap+dump
(and this looks like it might help you :
http://docs.oracle.com/javase/7/docs/technotes/tools/share/jhat.html)
To restate the obvious :
- this list here is manned by volunteers, who donate their time trying to help people who
have problems with Tomcat, and who are doing their best, but
- the list works best with people who also help themselves
- we do not have access to your system, and we do not know your applications
- we can only try to help, on the base of the information which you provide
- there are 3 (possible) components to your problem :
a) the Java JVM which runs Tomcat
b) Tomcat itself, which runs your applications
c) the applications themselves
Of these :
a) is controlled entirely by you, and is in fact the one which ultimately uses all that
memory (but we do not know why either). Below you are showing the startup parameters of
the JVM. They are not the default settings. So where do these parameters come from, and do
you understand them ? (if you don't, you first need help with Java, not with Tomcat)
b) That is really the focus of this list. And we know that Tomcat, by itself, does not
use 60GB or 10GB of memory, nor anywhere near it
c) we know nothing about, but it is likely that it is something there, which causes
Tomcat (and Java) to use all that memory
And about (c), maybe it is normal that it/they use this gigantic amount of memory. Maybe
one of the applications allocates some gigantic array of data over time. Maybe one of
these applications is really badly programmed and causes enormous "memory leaks". How
would we know ? Are these your applications ? If not, have you contacted the people
responsible for these applications, and described your problem to them ?
(because again, with 99& probability, that is where the problem is)
Try to collect some more specific data, and when you have it, post it here, and maybe
someone will have an idea. But as it is, the only thing known so far is that on your
system, the Java JVM which runs tomcat is using up a lot of memory, increasingly over
time, and that it ends up crashing with an OOM.
That is not enough information for us to be able to help you.
If you are desperate and in a hurry, maybe you need first to find a Java JVM specialist,
who can help you poinpoint the problem more specifically.
Regards,
On Thu, Aug 17, 2017 at 9:46 AM, Fady Haikal <fadyhai...@gmail.com> wrote:
@Suvendu,
I took a heap dump from Java VisualVM but honestly i didnt know how i
should analyse it, please some help here
also please find below the java configuration i used:
-XX:PermSize=10240m
-XX:MaxPermSize=10240m
-XX:ReservedCodeCacheSize=512m
-XX:+UseParNewGC
-XX:+UseConcMarkSweepGC
-XX:+CMSParallelRemarkEnabled
-XX:TargetSurvivorRatio=90
Initial and Max Memory Pool: 100000MB
Regards,
Fady
On Wed, Aug 16, 2017 at 5:46 PM, Suvendu Sekhar Mondal <suv3...@gmail.com>
wrote:
Hi Fady,
On Aug 16, 2017 7:04 PM, "Fady Haikal" <fadyhai...@gmail.com> wrote:
Dear Team,
I'm facing an issue that tomcat from task manager is consuming around 60
GB
of memory while from Oracle Java Mission Control is showing maximum 10 GB
(Attached screenshots), and from time to time the server hang due to
insufficent memory.
can you please advise why the above is showing like that? and why the
memory of the server is not reducing?
Tomcat Version: 8.0.30
JDK: 1.7.0_67
I couldn't find the screenshot. Anyway​, the issue you mentioned is very
interesting. Usually I saw some difference(in MB) between task manager
data
and JMC data...but not like this. Can you please let us know about the
Java Heap, Permgen and thread stack size configuration?
For starter, I will suggest to take a heap dump and look into it. It will
show you which objects are live and holding the memory. Also it will be
awesome if you can enable Native Memory Tracking for your TC instance.
Thanks!
Suvendu
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