Re: How do I get Tomcat 7 to start up faster in Linux CentOS kernel version 2.6.18?
Thank you for all your responses and apologies for my late reply. I got pulled off of this project last week and was assigned back to java coding (my preferred state in any case). I have forwarded your replies to the manager in charge of the project and someone in his team has been looking into it so I don't have any feedback just yet. I appreciate all the suggestions from this list and am hopeful they will help us pinpoint the cause of the slow start up times. We are using Tomcat 7 to load up our application written in struts. On production sites, the startup time can be as slow as 20 minutes. When I was testing on our QA environments, I saw much faster times, around 9 to 40 seconds, so there is a disconnect there. Our QA environment is not an exact duplicate of our production site so there could be variables in there to investigate as well. Regards, Dilshad On Wed, Oct 31, 2012 at 12:19 PM, Mark Thomas ma...@apache.org wrote: On 30/10/2012 21:55, Dilshad Shahid wrote: I am experiencing a problem with slow start up times for Tomcat 7. I have done some testing by tweaking configuration parameters both on Linux CentOS kernel version 2.6.18 and on Windows 7 using this link as my primary guide: http://wiki.apache.org/tomcat/HowTo/FasterStartUp and managed only a modest improvement. The improvements seemed to result when I added metadata-complete=true attribute to the element of my WEB-INF/web.xml file and when I added the names of almost all the jars we use for our application to the tomcat.util.scan.DefaultJarScanner.jarsToSkip property in conf/catalina.properties file. Use a servlet 3.0 web.xml, set metadata-complete=true and include an empty absolute ordering section and that will disable all of the Servlet 3.0 Jar scanning. Mark - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org -- dilshad.sha...@gmail.com - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: How do I get Tomcat 7 to start up faster in Linux CentOS kernel version 2.6.18?
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Dilshad, On 11/5/12 10:28 AM, Dilshad Shahid wrote: We are using Tomcat 7 to load up our application written in struts. On production sites, the startup time can be as slow as 20 minutes. When I was testing on our QA environments, I saw much faster times, around 9 to 40 seconds, so there is a disconnect there. Our QA environment is not an exact duplicate of our production site so there could be variables in there to investigate as well. I think we can all agree that 20 minutes is unreasonable. Given that, I have two suggestions for possible problems and their solutions: 1. Lack of entropy for randomness. If you are using SSL connectors or your application uses sessions that are configured to use a SecureRandom object for session id generation (which might actually be the default these days), then your Tomcat process will need sufficient entropy to launch. This is easily identified via a thread dump. Solutions: use /dev/urandom (not recommended) or something like an Entropy Key (http://www.entropykey.co.uk/). 2. Long DNS lookup timeouts coupled with huge numbers of URL lookups. This can happen if you have lots of XML files being parsed and validated against remote DTDs or Schemas. This is easily identified via a series of thread dumps (you may be noticing a pattern, here). Solutions: fix your DNS and/or use something like XML Catalog (http://en.wikipedia.org/wiki/XML_Catalog). I have forwarded your replies to the manager in charge of the project and someone in his team has been looking into it so I don't have any feedback just yet. You could save everyone some time and spend 2 minutes investigating this yourself: it doesn't take long to launch your app a few times and then get a thread dump while it's stalled. - -chris -BEGIN PGP SIGNATURE- Version: GnuPG/MacGPG2 v2.0.17 (Darwin) Comment: GPGTools - http://gpgtools.org Comment: Using GnuPG with Mozilla - http://www.enigmail.net/ iEYEARECAAYFAlCYFhsACgkQ9CaO5/Lv0PDcFgCgpWhmixVMac3kN7YwkdDKvyws NlAAmwbt8R49kF6VcjQTSHwJJYNFPYXz =wE7G -END PGP SIGNATURE- - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: How do I get Tomcat 7 to start up faster in Linux CentOS kernel version 2.6.18?
Dilshad, On 30.10.2012 22:55, Dilshad Shahid wrote: I am experiencing a problem with slow start up times for Tomcat 7. I have done some testing by tweaking configuration parameters both on Linux CentOS kernel version 2.6.18 and on Windows 7 using this link as my primary guide: http://wiki.apache.org/tomcat/HowTo/FasterStartUp and managed only a modest improvement. Tomcat 7 itself starts blazingly fast. Even on 5-years-old-average-web-server, fresh Tomcat 7 install starts in less than 200 ms. What are your numbers? If your FRESH Tomcat 7 installations starts fast, but Tomcat 7 with your webapp(s) deployed drags, then: (a) Try setting entropy source to /dev/./urandom as the document you referenced suggest. (b) If (a) does not work for you, you will have to find out why is your webapp slow. Use a profiler to find that out. -Ognjen - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: How do I get Tomcat 7 to start up faster in Linux CentOS kernel version 2.6.18?
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Dilshad, On 10/30/12 5:55 PM, Dilshad Shahid wrote: I am experiencing a problem with slow start up times for Tomcat 7. How slow is slow? If it takes long enough to take a thread dump, please take one or more thread dumps to see what the JVM is doing. Then we may be able to help you. - -chris -BEGIN PGP SIGNATURE- Version: GnuPG/MacGPG2 v2.0.17 (Darwin) Comment: GPGTools - http://gpgtools.org Comment: Using GnuPG with Mozilla - http://www.enigmail.net/ iEYEARECAAYFAlCRUVcACgkQ9CaO5/Lv0PDnVACfW+5RnIVWEVcgw/rNgN9HnRTN sTIAn1SRl4O1oQYvHTG6Sf4YQw4rbVaX =ucvL -END PGP SIGNATURE- - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: How do I get Tomcat 7 to start up faster in Linux CentOS kernel version 2.6.18?
On 30/10/2012 21:55, Dilshad Shahid wrote: I am experiencing a problem with slow start up times for Tomcat 7. I have done some testing by tweaking configuration parameters both on Linux CentOS kernel version 2.6.18 and on Windows 7 using this link as my primary guide: http://wiki.apache.org/tomcat/HowTo/FasterStartUp and managed only a modest improvement. The improvements seemed to result when I added metadata-complete=true attribute to the element of my WEB-INF/web.xml file and when I added the names of almost all the jars we use for our application to the tomcat.util.scan.DefaultJarScanner.jarsToSkip property in conf/catalina.properties file. Use a servlet 3.0 web.xml, set metadata-complete=true and include an empty absolute ordering section and that will disable all of the Servlet 3.0 Jar scanning. Mark - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
How do I get Tomcat 7 to start up faster in Linux CentOS kernel version 2.6.18?
I am experiencing a problem with slow start up times for Tomcat 7. I have done some testing by tweaking configuration parameters both on Linux CentOS kernel version 2.6.18 and on Windows 7 using this link as my primary guide: http://wiki.apache.org/tomcat/HowTo/FasterStartUp and managed only a modest improvement. The improvements seemed to result when I added metadata-complete=true attribute to the element of my WEB-INF/web.xml file and when I added the names of almost all the jars we use for our application to the tomcat.util.scan.DefaultJarScanner.jarsToSkip property in conf/catalina.properties file. I've also used this JAVA_OPTS in the setenv.sh file: JAVA_OPTS=$JAVA_OPTS -server -Xms1536m -Xmx1536m -XX:MaxPermSize=256m -XX:NewRatio=2 -XX:+UseParallelGC -XX:ParallelGCThreads=2 -Dsun.rmi.dgc.client.gcInterval=180 -Dsun.rmi.dgc.server.gcInterval=180 -Dorg.apache.jasper.runtime.BodyContentImpl.LIMIT_BUFFER=true but actually saw my start up times increase slightly. Our QA and production environments are on Linux CentOS so I'm hoping to get more information on improving Tomcat 7 start up times in that environment. My primary role is java developer and I don't have much system administration experience so I appreciate any input. Thank you for your time and suggestions. -- dilshad.sha...@gmail.com - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
