-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 Konstantin,
On 4/24/20 11:27, Konstantin Kolinko wrote: > пт, 24 апр. 2020 г. в 05:25, Christopher Schultz > <ch...@christopherschultz.net>: >> >> -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 >> >> Rafael, >> >> On 4/23/20 17:18, Rafael Oliveira wrote: >>> I does not happen every time, but it happens, actually it >>> happened twice during a couple of deployments and only in one >>> instance of several that I have. >>> >>> I could not reproduce in a safe and close environment, I got >>> this error in a server with multiple users and multiple tasks >>> and concurred environment. >>> >>> The point is raise a question is this echo $! > "CATALINA_PID" >>> the best approach to get the PID? >> >> It's literally the only way to do it. >> >> $! doesn't get you the PID of some random other process that was >> recently started. It's exactly what it says it is: the PID of the >> last process that was backgrounded by the currently-executing >> script. >> >> If your pid-file contains the wrong PID, it's probably because >> something overwrite overwrote it after it was >> initially-generated. >> >> If you try to start Tomcat twice, for example, like this: >> >> $ CATALINA_HOME/bin/startup.sh [...] $ cat $CATALINA_PID 1234 $ >> CATALINA_HOME/bin/startup.sh [...] $ cat $CATALINA_PID 2345 $ ps >> -ef | grep "catalina.base=$CATALINA_HOME" 1234 >> >> The startup script will always overwrite the PID file because it >> can't tell if it's going to fail (which it will, since the >> shutdown port is already bound to the first-launched instance). >> >> In the case above, the PID-file is clobbered by the second >> process while the first process continues to run (and be the >> correct process id). There isn't much to be done about that >> without resorting to drastic measures, such as having Tomcat >> write its own PID file after it starts up (enough), and getting >> the PID from Java isn't super-straightforward until Java 9. :( > > 1. I do not know what version of Tomcat the OP is using, but the > current catalina.sh has some protection from double runs: > > ps -p $PID >/dev/null 2>&1 if [ $? -eq 0 ] ; then echo "Tomcat > appears to still be running with PID $PID. Start aborted." echo "If > the following process is not a Tomcat process, remove the PID file > and try again:" ps -f -p $PID exit 1 else > > There is some time window between this check and the launch of > Java process (when the PID file is being written out), so there > will always be a race condition here. Yes, but it fails-safe. That is, Tomcat will not start if it thinks another Tomcat is already running. If there is a race, a second attempt to start Tomcat will likely succeed. > 2. If one does not like how Tomcat forks a separate shell process > for a java executable, it is possible to start it with "catalina.sh > run". In this case java is started in the same process (and no PID > file is being written) and all control over this process should be > done in your own code YMMV. > > 3. Tomcat can be configured as a service (daemon) and started with > Apache Commons Daemon executable (jsvc). jsvc knows how to manage > a PID file. See daemon.sh for an example. > >> and getting the PID from Java isn't super-straightforward until >> Java 9. :( > > 4. With our own cat's food: Tomcat-Native has the method: > > org.apache.tomcat.jni.Stdlib.getpid() Interesting, although that does require that tcnative is available. - -chris -----BEGIN PGP SIGNATURE----- Comment: Using GnuPG with Thunderbird - https://www.enigmail.net/ iQIzBAEBCAAdFiEEMmKgYcQvxMe7tcJcHPApP6U8pFgFAl6jF6IACgkQHPApP6U8 pFgzhRAApf5Rzn/0n8S2gCKorMlHftPWSo9BUoYkHBAqlMpYzIzVIxvpxujPBC5n P1/ifE+VqK98G6nkEKuJwQI3IZXNvd8zW3x6/rcVKhHG/0d81rYw2AeAxbAt4cUS JqQqwpbInOl0dpcWnkQic2KnjJP+qI25DGL0U3Rsx3J9T8tfQ11Dv9AIlepAO4uu KXgcs2JGlwv6vOzV2MkFuw6/0LkrDV4jlV1uYJFHj9CopO9x1ofNGupu6WjtlqiM FbIuPudmus8tmPP/TZ3lSjuj2Aw2kVq+7vBgsKLAVo/KIXifTP7DXXdiI4J2hcdG su+806PDsuEDwOKyMuWXhKzn2TuE+UVyxYMMTu1VrbX3GlIxPszjswpQgFAvLbNj GEQNarV18E/Ni6Zvw4PM1jJiMtcKyoPxUcVWbBkwDrMcqymPLdWrZEp/lBrwMsw6 XQHLzqHNl8ZUW6YIwd2a0VgycqJzPKVP8zfhvgUzf2NxtMzCNwckebZ4lvhD5S+T cZqCwfR+J8VNOlhB+52JLRl1aotqX5LYMI8HNwQAanfbg5e3940FeBeIZF9XZSb4 +IsVNlBdpS1bsv6yAGGrSk2drM85cHW6pBiEGhqfSfDDlm8xSURNaQLM27GWEQgD T2gbijw711xG3U3bRjoZa445IQ7ZN8phs9mA2n6eDi1WGXwM0Bs= =cdsU -----END PGP SIGNATURE----- --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
