-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 Roger,
On 8/27/20 14:43, Roger Marquis wrote: > Mark Thomas wrote: >> Those are all application issues. The application should shut >> itself down cleanly. Tomcat is complaining because it hasn't. > > I don't know Mark, most Java/Tomcat engineers expect an application > to shutdown when it's os/container/shell/parent shuts-down. Can > you help us understand why Tomcat is different in this respect than > say Apache httpd? Along with Mark's reply, there is also the fact that httpd doesn't really run "applications" per se. If you are using something like mod_php or CGI, then that's all ephemeral: once the request is done, the child process dies. Or, more specifically, the child process exits and that's what causes the response to be sent to the client. There is little to no notion of cross-request state in httpd. Requesting httpd to stop sends a signal to the primary httpd process which tells all its children to stop. If there is a problem with a child (e.g. it's processing a request, or stuck in some way), the primary process has to decide what to do about it. It may be able to SIGKILL it. Maybe not, depending upon process privileges (though the primary process usually runs as root, so it should be able to do that). For threaded MPMs, the primary or child process can choose what to do about killing the threads that appear stuck. The pthreads library has a pthread_cancel function which requests that the thread be stopped, but it does not guarantee anything. This is similar to Java, except that Java has gone so far as to say "the Thread.stop method should not be used" (because it is not reliable, it causes weirdness in the JVM, etc.). If you want to *kill* the application and it won't shut down on its own, SIGKILL is the answer. But that's not a great way to shut down an application /in general/ because the application might want/need to do something convenient on shutdown (flush caches, save state, etc.). The previous two paragraphs are mostly valid for both httpd AND Tomcat. The reason httpd is often "cleaner" than Tomcat sometimes is, is because of the applications running within Tomcat. httpd is really a web server, and Tomcat is an application container. Could Tomcat be more aggressive about killing applications when they aren't behaving appropriately? Maybe. But then you'd never fix your application, now would you? - -chris -----BEGIN PGP SIGNATURE----- Comment: Using GnuPG with Thunderbird - https://www.enigmail.net/ iQIzBAEBCAAdFiEEMmKgYcQvxMe7tcJcHPApP6U8pFgFAl9IInAACgkQHPApP6U8 pFi6zw//WBFH087QqzmZbgdQjPxDhZ5f5L9lQmp4VFaw+dOEkP4xNMkGCxWeTq1Z 1nmogFYsZ8vns8z1f8RJ22aDWhdFqCDDHlJkqobR/4d4wiKd0hmjm75s8NH2YeCk 2UwwlStV99n5BNu3/TBTQFyjUv2rhz8cO8tDkztFGS7avXogSm08zeeHgVIC8cWV tiGBe7QVH/PMeanGl+/1IdWQ5PmpmNpGBv5YGJMYfU9Hmul/GeNW55pLJPSxS7ll /8thgxDVK4VudnA6MGELVSht56qlEQtlekMJjSUUvagmT94yTDXd7teOagZL9U79 26EL5tOiSkE4GGPoR/jQa0kj0bNMHMUJsBJRoHDCXxQdJhPLTGZNKZM1yMgAlMnc 6D2/acg9TbO6ia0Q1qpQmh2vWUlMPdp4U8X1uP6RdKKQyyjM5Pzinw/ysktgEBpI lYSI+uz3uG0iJGzqECPaoTpTTtSqdtG68QVqU2Kgv4lHmENNHFWMDKbB3glwqfBN KLw6fCrKGG6XGdQEcgtR8GjyNNpErLcf7PzIqXtwo9bNoQWNhYF/VjjndRJTTL98 IwoEL9qHXs0hhtKHA4x7kir0OARjwXDNwuJGu9LrKX1qOtzNxUAmjckHtLDjb5m8 nWmsz2zzy1rak1t1EPVsFjfOu5kZL+++IQcXja29uZshuiPcWbI= =vc24 -----END PGP SIGNATURE----- --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
