Shell代码 1.#启动tomcat 2../catalina.sh start 3. 4.#关闭tomcat 5../catalina.sh stop #启动tomcat ./catalina.sh start #关闭tomcat ./catalina.sh stop
往往一个工程,开发一段时间后,会发现./catalina.sh stop关闭不了tomcat,而必须使用kill -9 <pid> 这样的强制命令去
杀死tomcat,这么做当然可以,但是手法不是那么的优雅
在tomat未被./catalina stop关闭的情况下,导致误以为tomcat已经关闭成功的哥们 会在更新完代码后,./catalina start一下,于是在服务器中就产生了2个tomcat的实例,log混乱,不知所措,ps 一看,大吃一惊,而后每次都用kill -9 <pid> 才放心。
其实不用那样,一般关闭不了的情况,是由于程序员自己在tomcat中开启了新的线程,而且未设置成daemon,造成的主线程不能退出.
怎么发现工程里到底哪里开启的新的非守护线程呢,其实jdk提供了jstack工具,可以帮助我们分析
查看方法很简单
$JAVA_HOME/bin/jstack <pid>
pid是指进程ID, 用ps -ef|grep tomcat 就可以查看到:
Shell代码 1.[root@localhost bin]# ps -ef|grep tomcat 2.root 1513 1 2 23:41 pts/1 00:00:01 /usr/local/share/java/jdk1.6.0_25/bin/java -Djava.util.logging.config.file=/opt/apache-tomcat-6.0.32/conf/logging.properties -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -Djava.endorsed.dirs=/opt/apache-tomcat-6.0.32/endorsed -classpath /opt/apache-tomcat-6.0.32/bin/bootstrap.jar -Dcatalina.base=/opt/apache-tomcat-6.0.32 -Dcatalina.home=/opt/apache-tomcat-6.0.32 -Djava.io.tmpdir=/opt/apache-tomcat-6.0.32/temp org.apache.catalina.startup.Bootstrap start 3.root 1544 1462 0 23:42 pts/1 00:00:00 grep --color=auto tomcat [root@localhost bin]# ps -ef|grep tomcat root 1513 1 2 23:41 pts/1 00:00:01 /usr/local/share/java/jdk1.6.0_25/bin/java -Djava.util.logging.config.file=/opt/apache-tomcat-6.0.32/conf/logging.properties -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -Djava.endorsed.dirs=/opt/apache-tomcat-6.0.32/endorsed -classpath /opt/apache-tomcat-6.0.32/bin/bootstrap.jar -Dcatalina.base=/opt/apache-tomcat-6.0.32 -Dcatalina.home=/opt/apache-tomcat-6.0.32 -Djava.io.tmpdir=/opt/apache-tomcat-6.0.32/temp org.apache.catalina.startup.Bootstrap start root 1544 1462 0 23:42 pts/1 00:00:00 grep --color=auto tomcat
这里看到的进程ID是 1513
调用jstack查看:
Shell代码 1.[root@localhost bin]# jstack 1513 2.2011-07-12 23:44:00 3.Full thread dump Java HotSpot(TM) Client VM (20.0-b11 mixed mode, sharing): 4. 5."Attach Listener" daemon prio=10 tid=0xb41d7c00 nid=0x606 waiting on condition [0x00000000] 6. java.lang.Thread.State: RUNNABLE 7. 8."TP-Monitor" daemon prio=10 tid=0xb41d6400 nid=0x5fa in Object.wait() [0xb3e0b000] 9. java.lang.Thread.State: TIMED_WAITING (on object monitor) 10. at java.lang.Object.wait(Native Method) 11. - waiting on <0x87143720> (a org.apache.tomcat.util.threads.ThreadPool$MonitorRunnable) 12. at org.apache.tomcat.util.threads.ThreadPool$MonitorRunnable.run(ThreadPool.java:565) 13. - locked <0x87143720> (a org.apache.tomcat.util.threads.ThreadPool$MonitorRunnable) 14. at java.lang.Thread.run(Thread.java:662) 15. 16."TP-Processor4" daemon prio=10 tid=0xb41d4c00 nid=0x5f9 runnable [0xb3e5c000] 17. java.lang.Thread.State: RUNNABLE 18. at java.net.PlainSocketImpl.socketAccept(Native Method) 19. at java.net.PlainSocketImpl.accept(PlainSocketImpl.java:408) 20. - locked <0x87124770> (a java.net.SocksSocketImpl) 21. at java.net.ServerSocket.implAccept(ServerSocket.java:462) 22. at java.net.ServerSocket.accept(ServerSocket.java:430) 23. at org.apache.jk.common.ChannelSocket.accept(ChannelSocket.java:311) 24. at org.apache.jk.common.ChannelSocket.acceptConnections(ChannelSocket.java:668) 25. at org.apache.jk.common.ChannelSocket$SocketAcceptor.runIt(ChannelSocket.java:879) 26. at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:690) 27. at java.lang.Thread.run(Thread.java:662) [root@localhost bin]# jstack 1513 2011-07-12 23:44:00 Full thread dump Java HotSpot(TM) Client VM (20.0-b11 mixed mode, sharing): "Attach Listener" daemon prio=10 tid=0xb41d7c00 nid=0x606 waiting on condition [0x00000000] java.lang.Thread.State: RUNNABLE "TP-Monitor" daemon prio=10 tid=0xb41d6400 nid=0x5fa in Object.wait() [0xb3e0b000] java.lang.Thread.State: TIMED_WAITING (on object monitor) at java.lang.Object.wait(Native Method) - waiting on <0x87143720> (a org.apache.tomcat.util.threads.ThreadPool$MonitorRunnable) at org.apache.tomcat.util.threads.ThreadPool$MonitorRunnable.run(ThreadPool.java:565) - locked <0x87143720> (a org.apache.tomcat.util.threads.ThreadPool$MonitorRunnable) at java.lang.Thread.run(Thread.java:662) "TP-Processor4" daemon prio=10 tid=0xb41d4c00 nid=0x5f9 runnable [0xb3e5c000] java.lang.Thread.State: RUNNABLE at java.net.PlainSocketImpl.socketAccept(Native Method) at java.net.PlainSocketImpl.accept(PlainSocketImpl.java:408) - locked <0x87124770> (a java.net.SocksSocketImpl) at java.net.ServerSocket.implAccept(ServerSocket.java:462) at java.net.ServerSocket.accept(ServerSocket.java:430) at org.apache.jk.common.ChannelSocket.accept(ChannelSocket.java:311) at org.apache.jk.common.ChannelSocket.acceptConnections(ChannelSocket.java:668) at org.apache.jk.common.ChannelSocket$SocketAcceptor.runIt(ChannelSocket.java:879) at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:690) at java.lang.Thread.run(Thread.java:662)
其中看到"Attach Listener" daemon prio=10 tid=0xb41d7c00 nid=0x606 waiting on condition [0x00000000]
java.lang.Thread.State: RUNNABLE
这行,最前变的"Attach Listener" 是线程名, 紧跟其后的 daemon是线程的守护状态,
其中主线程不是daemon的,所以是这样:
"main" prio=10 tid=0xb6d05000 nid=0x5ea runnable [0xb6ee9000] java.lang.Thread.State: RUNNABLE at java.net.PlainSocketImpl.socketAccept(Native Method) at java.net.PlainSocketImpl.accept(PlainSocketImpl.java:408) - locked <0x871644a8> (a java.net.SocksSocketImpl) at java.net.ServerSocket.implAccept(ServerSocket.java:462) at java.net.ServerSocket.accept(ServerSocket.java:430) at org.apache.catalina.core.StandardServer.await(StandardServer.java:431) at org.apache.catalina.startup.Catalina.await(Catalina.java:676) at org.apache.catalina.startup.Catalina.start(Catalina.java:628) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:289) at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:414)
在"main" 后没有daemon,看到这样的线程状态,顺藤摸瓜,找到对应new Thread的地方setDaemon(true)就可以,痛痛快快的./catalina stop了 :)