RE: creating a instance of a servlet: takes too long!!
why is that my servlet when the first time is invoked, it takes about 30 seconds or more to start when the servlets that came in tomcat are instantaneous? After the servlet container instantiated and initialized my servlet, all the following requests are very fast. Is there any advice for what we should do and don't do in init() method? Well, one option for a solution is set your servlet to load on startup and have all your initialization done at startup so that these elements are already initialized before the first request even comes. How can I benchmark the time of instantiation of my servlet and the time of my init method? I would just put in some logging code and find out where exactly the time is being taken up in your servlet(if indeed this is where it is actually munching clock cycles). --- Michael Wentzel Software Developer Software As We Think - http://www.aswethink.com
RE: creating a instance of a servlet: takes too long!!
Really it depends upon what you are doing in your init method. I have several servlets that load almost instantly, but don't do anything in their constructor or init methods. The only thing that you should do in your init method is to call super.init at the beginning. If you want to move the time it takes to initialize, you could use the web.xml's load-on-startup tag (see the spec for more details) to load the servlet at Tomcat startup. You servlet should stay in memory until its shutdown - Tomcat keeps a reference to the servlet, thus preventing it from being garbage collected. The only reason, I believe, that a servlet is unloaded during the middle of Tomcat execution is a newer version is detected on disk. Randy -Original Message- From: pedro salazar [mailto:[EMAIL PROTECTED]] Sent: Friday, July 06, 2001 5:02 AM To: [EMAIL PROTECTED] Subject: creating a instance of a servlet: takes too long!! Greetings, why is that my servlet when the first time is invoked, it takes about 30 seconds or more to start when the servlets that came in tomcat are instantaneous? After the servlet container instantiated and initialized my servlet, all the following requests are very fast. Is there any advice for what we should do and don't do in init() method? I just initialize some properties and a connection pool Well is it possible that my servlet container at any time my may shutdown my servlet to release memory, and another time it will be requested to start again and take another time too long to start, correct? How can I benchmark the time of instantiation of my servlet and the time of my init method? System configuration: -Tomcat 3.2.1 -JDK 1.3 -Linux RedHat 6.2 [kernel 2.2.18] -PII400Mhz 256Mbytes thanks. -- psalazar/
Re: creating a instance of a servlet: takes too long!!
Friday, July 06, 2001, 5:01:37 AM, [EMAIL PROTECTED] wrote: ps Greetings, ps why is that my servlet when the first time is invoked, it takes about 30 ps seconds or more to start when the servlets that came in tomcat are ps instantaneous? After the servlet container instantiated and initialized my ps servlet, all the following requests are very fast. Is there any advice for ps what we should do and don't do in init() method? I just initialize some ps properties and a connection pool ps Well is it possible that my servlet container at any time my may shutdown my ps servlet to release memory, and another time it will be requested to start ps again and take another time too long to start, correct? ps How can I benchmark the time of instantiation of my servlet and the time of ps my init method? ps System configuration: ps -Tomcat 3.2.1 ps -JDK 1.3 ps -Linux RedHat 6.2 [kernel 2.2.18] ps -PII400Mhz 256Mbytes ps thanks. ps -- ps psalazar/
Re: creating a instance of a servlet: takes too long!!
If your servlet has changed and needs to be recompiled, then using jikes instead of javac will save a lot of time. Friday, July 06, 2001, 5:01:37 AM, [EMAIL PROTECTED] wrote: ps Greetings, ps why is that my servlet when the first time is invoked, it takes about 30 ps seconds or more to start when the servlets that came in tomcat are ps instantaneous? After the servlet container instantiated and initialized my ps servlet, all the following requests are very fast. Is there any advice for ps what we should do and don't do in init() method? I just initialize some ps properties and a connection pool ps Well is it possible that my servlet container at any time my may shutdown my ps servlet to release memory, and another time it will be requested to start ps again and take another time too long to start, correct? ps How can I benchmark the time of instantiation of my servlet and the time of ps my init method? ps System configuration: ps -Tomcat 3.2.1 ps -JDK 1.3 ps -Linux RedHat 6.2 [kernel 2.2.18] ps -PII400Mhz 256Mbytes ps thanks. ps -- ps psalazar/
RE: creating a instance of a servlet: takes too long!!
The connection pool could cause your problem. If it initiates many database connections, it is normal even if your db server was on the same machine than your app server, for it to take a few seconds per connection. Fred -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] Sent: Friday, July 06, 2001 9:18 AM To: [EMAIL PROTECTED] Subject: Re: creating a instance of a servlet: takes too long!! If your servlet has changed and needs to be recompiled, then using jikes instead of javac will save a lot of time. Friday, July 06, 2001, 5:01:37 AM, [EMAIL PROTECTED] wrote: ps Greetings, ps why is that my servlet when the first time is invoked, it takes about 30 ps seconds or more to start when the servlets that came in tomcat are ps instantaneous? After the servlet container instantiated and initialized my ps servlet, all the following requests are very fast. Is there any advice for ps what we should do and don't do in init() method? I just initialize some ps properties and a connection pool ps Well is it possible that my servlet container at any time my may shutdown my ps servlet to release memory, and another time it will be requested to start ps again and take another time too long to start, correct? ps How can I benchmark the time of instantiation of my servlet and the time of ps my init method? ps System configuration: ps -Tomcat 3.2.1 ps -JDK 1.3 ps -Linux RedHat 6.2 [kernel 2.2.18] ps -PII400Mhz 256Mbytes ps thanks. ps -- ps psalazar/
Re: creating a instance of a servlet: takes too long!!
pedro salazar wrote: Greetings, why is that my servlet when the first time is invoked, it takes about 30 seconds or more to start when the servlets that came in tomcat are instantaneous? After the servlet container instantiated and initialized my servlet, all the following requests are very fast. Is there any advice for what we should do and don't do in init() method? I just initialize some properties and a connection pool Well is it possible that my servlet container at any time my may shutdown my servlet to release memory, and another time it will be requested to start again and take another time too long to start, correct? How can I benchmark the time of instantiation of my servlet and the time of my init method? System configuration: -Tomcat 3.2.1 -JDK 1.3 -Linux RedHat 6.2 [kernel 2.2.18] -PII400Mhz 256Mbytes thanks. -- psalazar/ Hi :-) one of the ways is like the following: in WEB-INF/web.xml, add the following into the servlet-declaration of MyServlet: ... load-on-startup1/load-on-startup ... now MyServlet will be loaded/initialized when TC startup. Bo June 06, 2001
Re: creating a instance of a servlet: takes too long!!
There's another reason for this and it has to do with the java.security.SecureRandom class. From what I can tell, tomcat uses this class to generate a seed value for the session ID. The first request for a SecureRandom value (eg. new SecureRandom().nextLong()) can take many, many seconds to complete. After the first usage however, it returns immediately. I'm not sure what goes on when SecureRandom initializes but that seems to be where the slow down occurs. As a work around, you could create a low priority thread that instantiates a SecureRandom calls nextLong() then exits, and have this thread get launched by the init() method of a servlet that gets preloaded. This solution worked for me. Regards, Pete. Thus spake pedro salazar [EMAIL PROTECTED] on Fri, 6 Jul 2001 10:01:37 +0100: PS Greetings, PS PS why is that my servlet when the first time is invoked, it takes about 30 PS seconds or more to start when the servlets that came in tomcat are PS instantaneous? After the servlet container instantiated and initialized my PS servlet, all the following requests are very fast. Is there any advice for PS what we should do and don't do in init() method? I just initialize some PS properties and a connection pool PS Well is it possible that my servlet container at any time my may shutdown my PS servlet to release memory, and another time it will be requested to start PS again and take another time too long to start, correct? PS PS How can I benchmark the time of instantiation of my servlet and the time of PS my init method? PS PS System configuration: PS -Tomcat 3.2.1 PS -JDK 1.3 PS -Linux RedHat 6.2 [kernel 2.2.18] PS -PII400Mhz 256Mbytes PS PS thanks. PS -- PS psalazar/ PS PS
Re: creating a instance of a servlet: takes too long!!
Bo Xu wrote: pedro salazar wrote: Greetings, why is that my servlet when the first time is invoked, it takes about 30 seconds or more to start when the servlets that came in tomcat are instantaneous? After the servlet container instantiated and initialized my servlet, all the following requests are very fast. Is there any advice for what we should do and don't do in init() method? I just initialize some properties and a connection pool Well is it possible that my servlet container at any time my may shutdown my servlet to release memory, and another time it will be requested to start again and take another time too long to start, correct? How can I benchmark the time of instantiation of my servlet and the time of my init method? System configuration: -Tomcat 3.2.1 -JDK 1.3 -Linux RedHat 6.2 [kernel 2.2.18] -PII400Mhz 256Mbytes thanks. -- psalazar/ Hi :-) one of the ways is like the following: in WEB-INF/web.xml, add the following into the servlet-declaration of MyServlet: ... load-on-startup1/load-on-startup ... now MyServlet will be loaded/initialized when TC startup. Bo June 06, 2001 Hi :-) I forgot the following: with TC4.0-b5, when load-on-startup1/load-on-startup, I remember: - MyServlet is loaded, i.e.: One Class object of MyServlet is made - One instance of MyServlet is made, this instance is for that sevlet-declaration which you set load-on-startup1/load-on-startup for - init(...) method of this instance is invoked, then, for example, your DBconnectionPool is initialized But: you must use That servlet-name/servlet-mapping to invoke MyServlet, otherwise, another instance of MyServlet will be made, and its init(...) will Still be invoked, i.e.: the first time will Still be slow. and it is possible that container will invoke int(...)/destroy() more than one time. Bo July 06, 2001
RE: creating a instance of a servlet: takes too long!!
Note that a good deal of this time might be spent in HttpServletRequest.getSession(): the 3.2.1 implementation is much slower than the 3.2.2 version. You might want to time your calls and, if that's where the slow-down is, upgrade to 3.2.2. -- Bill K. -Original Message- From: pedro salazar [mailto:[EMAIL PROTECTED]] Sent: Friday, July 06, 2001 2:02 AM To: [EMAIL PROTECTED] Subject: creating a instance of a servlet: takes too long!! Greetings, why is that my servlet when the first time is invoked, it takes about 30 seconds or more to start when the servlets that came in tomcat are instantaneous? After the servlet container instantiated and initialized my servlet, all the following requests are very fast. Is there any advice for what we should do and don't do in init() method? I just initialize some properties and a connection pool Well is it possible that my servlet container at any time my may shutdown my servlet to release memory, and another time it will be requested to start again and take another time too long to start, correct? How can I benchmark the time of instantiation of my servlet and the time of my init method? System configuration: -Tomcat 3.2.1 -JDK 1.3 -Linux RedHat 6.2 [kernel 2.2.18] -PII400Mhz 256Mbytes thanks. -- psalazar/
