I'm gonna try to make a guess here :) > top - 08:20:02 up 72 days, 9:39, 4 users, load average: 6.83, 5.63, 3.16 > Tasks: 265 total, 1 running, 264 sleeping, 0 stopped, 0 zombie > Cpu(s): 0.2%us, 0.1%sy, 0.0%ni, 99.2%id, 0.5%wa, 0.0%hi, 0.0%si, 0.0%st > Mem: 12328624k total, 11382976k used, 945648k free, 123400k buffers > Swap: 4882424k total, 860k used, 4881564k free, 7565012k cached
- somewhat large load average (6.83) - but no io waiting (0.5%wa), - app is heavily used - tomcat requests take long time (sometimes takes few seconds to produce the answer). Could it be a lack of threads at apache or tomcat? On Tue, Apr 12, 2011 at 12:20 PM, André Warnier <a...@ice-sa.com> wrote: > Hi. > > I have a Linux application server running Apache + mod_jk + tomcat 5.5 (I > know that it is relatively old; and to compound the heresy, it is installed > from a Debian package). > The hardware is quite OK (quad-core fast CPU, 12 GB RAM). > > Apache is serving most of the static content, and passing some requests to > Tomcat via AJP. Tomcat runs basically a single application, but this > webapp, although itself quite small, can be heavily used : it is an > interface to a text retrieval system (a kind of database specialised for > textual data), and some of the searches made by users can take several > seconds to come back with results, which may themselves be several pages of > data. > > I can access the host remotely via SSH and via HTTP, and have full control > of it. > But it is a productive customer server, so there are limits to what I can > do. > > I am having performance issues with that system : users at times complain > that "they cannot access the application", and I see things like this in a > "top" display : > > top - 08:20:02 up 72 days, 9:39, 4 users, load average: 6.83, 5.63, 3.16 > Tasks: 265 total, 1 running, 264 sleeping, 0 stopped, 0 zombie > Cpu(s): 0.2%us, 0.1%sy, 0.0%ni, 99.2%id, 0.5%wa, 0.0%hi, 0.0%si, > 0.0%st > Mem: 12328624k total, 11382976k used, 945648k free, 123400k buffers > Swap: 4882424k total, 860k used, 4881564k free, 7565012k cached > > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND > 2023 tomcat55 20 0 627m 184m 9344 S 333 1.5 32:00.47 jsvc > 5396 root 20 0 832m 610m 9224 S 100 5.1 12:32.43 java > 1 root 20 0 10316 760 624 S 0 0.0 0:33.14 init > > (where I presume that if tomcat is showing 333% CPU usage, it is because it > is running on multiple cores; the second task visible above is the interface > to the search engine). > > Anyway, my question is : > > Considering all the above, which would be the easiest/quickest way of > starting to figure out what this tomcat is doing, and where the > system/application bottleneck might be ? > > My preference would be in an easy tool to install and run, to first get a > rough idea, and then maybe select more specific tools to examine one or the > other area more in-depth. > Or maybe I can just first add some command-line switches to the JVM running > tomcat, to give me more information in the logs ? > > (My workstation is Windows XP, and I can install anything I want on it.) > > Additional details : > > Platform : (Linux 64-bit) > # uname -a > Linux vogon2 2.6.26-2-amd64 #1 SMP Thu Nov 25 04:30:55 UTC 2010 x86_64 > GNU/Linux > > Tomcat and Java : > > Using CATALINA_BASE: /usr/share/tomcat5.5 > Using CATALINA_HOME: /usr/share/tomcat5.5 > Using CATALINA_TMPDIR: /usr/share/tomcat5.5/temp > Using JRE_HOME: /usr/lib/jvm/java-6-sun > Server version: Apache Tomcat/5.5 > Server built: Oct 15 2008 12:57:44 > Server number: 5.5.26.0 > OS Name: Linux > OS Version: 2.6.26-2-amd64 > Architecture: amd64 > JVM Version: 1.6.0_22-b04 > JVM Vendor: Sun Microsystems Inc. > vogon2:/usr/share/tomcat5.5/bin# > > Tomcat is started as : > tomcat55 2023 2021 6 Apr11 ? 00:31:58 /usr/bin/jsvc -user tomcat55 > -cp > /usr/share/java/commons-daemon.jar:/usr/share/tomcat5.5/bin/bootstrap.jar > -outfile SYSLOG -errfile SYSLOG -pidfile /var/run/tomcat5.5.pid > -Djava.awt.headless=true -Xms128M -Xmx128M > -Djava.endorsed.dirs=/usr/share/tomcat5.5/common/endorsed > -Dcatalina.base=/var/lib/tomcat5.5 -Dcatalina.home=/usr/share/tomcat5.5 > -Djava.io.tmpdir=/var/lib/tomcat5.5/temp > -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager > -Djava.util.logging.config.file=/var/lib/tomcat5.5/conf/logging.properties > org.apache.catalina.startup.Bootstrap > > (which I don't think is a lot of heap space, which may be a problem here. > But before I change it, I'd like to know why I change it; the server.xml > settings are pretty much the standard issue, all defaults for threads > etc..). > > Apache and mod_jk : > > Apache/2.2.9 (Debian) DAV/2 mod_jk/1.2.26 mod_apreq2-20051231/2.6.0 > mod_perl/2.0.4 Perl/v5.10.0 configured > > Thanks in advance for any recommendation > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org > For additional commands, e-mail: users-h...@tomcat.apache.org > > -- Why? Because YES! --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
