On Nov 6, 2010, at 2:17 PM, Christopher Schultz wrote: >> I believe (if I heard it correctly), either Mark T. or Tim F. >> explained at ApacheCon this week that the minimum is not immediate. >> It needs to build up to that level. So, when you start Tomcat, you >> won't immediately fire up 150 threads for the executor pool, but once >>> = 150 threads are created in the process of serving requests, it >> will always keep a minimum of 150 for you. > > If that's the case, I find that surprising. I always like to avoid > violating the principle of least surprise. minSpareThreads as a name > implies to me that those spares are /always/ available, even immediately > after startup.
Chris - If you look in org.apache.catalina.core.StandardThreadExecutor, you will see that it is using a ThreadPoolExecutor. setMinSpareThreads() calls setCorePoolSize() in the ThreadPoolExecutor. If you read the javadoc for ThreadPoolExecutor, specifically the subsections labeled "Core and maximum pool sizes" and "On-demand construction", you will see that the threads are created on demand unless you use prestartCoreThread()/prestartAllCoreThreads(), which Tomcat does not. So, although it may seem surprising or even counterintuitive, all 150 will not be fired up on startup. Perhaps we could add a separate attribute on the Executor (e.g. startThreads)? Then Tomcat would have a paradigm similar to httpd's Start(Servers|Threads) and MinSpare(Servers|Threads). Any interest in such an attribute? It would be fairly simple to roll a patch for it... --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
