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View Full Version : [ubuntu] Lucid and Tomcat with "too many open files"



brettermeier01
September 27th, 2010, 03:10 PM
Hi all,

our tomcat is running into problem while open files (connections)

the catalina.out logs "too many open files" after some minutes with high traffic load on the application.

a look with "lsof | grep tomcat6 | wc -l" shows "only" 1040 to 1080 open files with tomcat6

I have configured the parameters in "/etc/security/limits.conf":



56 tomcat6 soft nofile 400000
57 tomcat6 hard nofile 500000
58
59 * soft nofile 49152
60 * hard nofile 65535
as well as the "/etc/pam.d/common-session(-noninteractive)":


15 session required pam_limits.soAn "ulimit -Ha shows for the user "tomcat6":



core file size (blocks, -c) unlimited
data seg size (kbytes, -d) unlimited
scheduling priority (-e) 20
file size (blocks, -f) unlimited
pending signals (-i) 16382
max locked memory (kbytes, -l) 64
max memory size (kbytes, -m) unlimited
open files (-n) 500000
pipe size (512 bytes, -p) 8
POSIX message queues (bytes, -q) 819200
real-time priority (-r) 0
stack size (kbytes, -s) unlimited
cpu time (seconds, -t) unlimited
max user processes (-u) unlimited
virtual memory (kbytes, -v) unlimited
file locks (-x) unlimited
I dont have an idea, where the limit is set. Is there a limit in the ubuntu tomcat?

some additional infos:



dpkg -l | grep tomcat6
ii libtomcat6-java 6.0.24-2ubuntu1.2 Servlet and JSP engine -- core libraries
ii tomcat6 6.0.24-2ubuntu1.2 Servlet and JSP engine
ii tomcat6-admin 6.0.24-2ubuntu1.2 Servlet and JSP engine -- admin web applicat
ii tomcat6-common 6.0.24-2ubuntu1.2 Servlet and JSP engine -- common files
ii tomcat6-docs 6.0.24-2ubuntu1.2 Servlet and JSP engine -- documentation
ii tomcat6-examples 6.0.24-2ubuntu1.2 Servlet and JSP engine -- example web applic


uname -a
Linux web2 2.6.32-24-server #39-Ubuntu SMP Wed Jul 28 06:21:40 UTC 2010 x86_64 GNU/Linux
Thanks
Christian

BOK
December 20th, 2010, 09:00 PM
Any news on this, since we have the same issue..?
Tomcat6 is ignoring the entries in limits.conf (set to 4096 for all users):




ps wwwaux | grep tomcat6
tomcat6 16258 35.8 22.2 5191168 1823964 ? Sl 10:39 216:31 /usr/lib/jvm/java-6-sun/bin/java -Djava.util.logging.config.file=/var/lib/tomcat6/conf/logging.properties -Djava.awt.headless=true -Xms256M -Xmx4096M -XX:MaxPermSize=256M -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -DjvmRoute=xy2 -Djava.io.tmpdir=/var/tmp -Drepo.upgrade=false -Djava.util.logging.manager=org.apache.juli.ClassLo aderLogManager -Xms256M -Xmx4096M -XX:MaxPermSize=256M -Djava.endorsed.dirs=/usr/share/tomcat6/endorsed -classpath /usr/share/tomcat6/bin/bootstrap.jar -Dcatalina.base=/var/lib/tomcat6 -Dcatalina.home=/usr/share/tomcat6 -Djava.io.tmpdir=/var/tmp/tomcat6-temp org.apache.catalina.startup.Bootstrap start

# cat /proc/16258/limits
Limit Soft Limit Hard Limit Units
Max cpu time unlimited unlimited seconds
Max file size unlimited unlimited bytes
Max data size unlimited unlimited bytes
Max stack size 8388608 unlimited bytes
Max core file size 0 unlimited bytes
Max resident set unlimited unlimited bytes
Max processes unlimited unlimited processes
Max open files 1024 1024 files
Max locked memory 65536 65536 bytes
Max address space unlimited unlimited bytes
Max file locks unlimited unlimited locks
Max pending signals 16382 16382 signals
Max msgqueue size 819200 819200 bytes
Max nice priority 20 20
Max realtime priority 0 0
Max realtime timeout unlimited unlimited us


Seems that Gentoo is suffering from the same "bug":
http://forums.gentoo.org/viewtopic-t-821751-start-0.html

BOK
December 27th, 2010, 08:44 PM
The above issue is all "start-stop-daemon" related...
There seems to be a patch waiting for at least 5 years now:
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=302079

In "the meantime" a workaround / hack for us was to add these lines in /etc/init.d/tomcat6:

ulimit -Hn 16384
ulimit -Sn 16384