thread-dump

问题 I am surprised to discover that somehow, recently, jstack stopped working on newer JDK 8. I am not sure around which release this happened but I do get: 36649: Unable to open socket file: target process not responding or HotSpot VM not loaded The -F option can be used when the target process is not responding ps -Af|grep 36649 conflue+ 36649 1 62 08:14 ? 00:48:28 /usr/lib/jvm/java-8-oracle/bin/java -Djava.util.logging.config.file=/opt/atlassian/confluence/conf/logging.properties -Djava.util

问题 Is there a possibility that kill -3 / quit PID prints nothing i.e. an empty thread dump? We heard a story from a support engineer and was wondering if some experts could validate. This is on Java 6_26 on RHEL 5 回答1: I have only seen this when the server redirects to stdout, like JBoss, and stdout has been redirected to /dev/null because whoever set up the server thought that everything going to stdout was already going to a named log file. 回答2: The console output of JVM thread dump on some

问题 The question is around the discussion "Multiple Java threads seemingly locking same monitor". In our application, we are facing similar issue. Sometimes the application is running extremely slow. Multiple thread dumps have been captured. The thread dumps indicate that 2/3 threads have acquired the same lock object at the same point of time and are in the BLOCKED state. Other threads (10 to 20 in number at different point of time) are BLOCKED while waiting for the very same lock object. Pseudo

问题 My thread TP-Processor27 is waiting, tells me a thread dump. Usually WAITING (on object monitor) lines are immediately followed by a waiting on <0x09c34480> or similar line. But not in the dump below. In such cases, can I know on which id is the wait? "TP-Processor27" daemon prio=10 tid=0x00002aab91c88800 nid=0x58d7 in Object.wait() [0x0000000050d01000] java.lang.Thread.State: WAITING (on object monitor) at java.lang.Object.wait(Native Method) at java.lang.Object.wait(Object.java:485) at org

问题 I sometimes have to look at thread dumps from a Tomcat server. However, this is a very slow process as my application uses thread pools with a couple of hundred threads. Most of the thread dumps I look at include the same stack trace for many of the threads as they are idle waiting for work. Are there any tools which would parse a thread dump and only show me the unique stack traces along with a count of the number of threads in each state? This would allow me to quickly ignore the tens or

问题 I am continuing my path to deep understanding of Java Thread. Unfortunately my Java Certification didn't cover that part, so the only way of learning is to post a series of dumb questions. With so many years of Java Development, I am sometimes wondering how much I still have to learn :-) In particular my attention is now with the reference handler thread. "Reference Handler" daemon prio=10 tid=0x02da3400 nid=0xb98 in Object.wait() [0x0302f000] java.lang.Thread.State: WAITING (on object

问题 I am continuing my path to deep understanding of Java Thread. Unfortunately my Java Certification didn't cover that part, so the only way of learning is to post a series of dumb questions. With so many years of Java Development, I am sometimes wondering how much I still have to learn :-) In particular my attention is now with the reference handler thread. "Reference Handler" daemon prio=10 tid=0x02da3400 nid=0xb98 in Object.wait() [0x0302f000] java.lang.Thread.State: WAITING (on object

问题 Is there away to take a thread dump from Tomcat. I want to monitor the running threads on Tomcat at a certain time. Note: I was doing that on Web logic but i don't know how it cab be done on Tomcat. 回答1: If you use Linux, you can send a kill -3 [pid of your tomcat] and it will dump all current threads in the catalina.out. 回答2: There is a simple way to monitor tomcat threads and do a dump. Start tomcat with the folowing java options : -Dcom.sun.management.jmxremote.port=<some free port> -Dcom

问题 Is there away to take a thread dump from Tomcat. I want to monitor the running threads on Tomcat at a certain time. Note: I was doing that on Web logic but i don't know how it cab be done on Tomcat. 回答1: If you use Linux, you can send a kill -3 [pid of your tomcat] and it will dump all current threads in the catalina.out. 回答2: There is a simple way to monitor tomcat threads and do a dump. Start tomcat with the folowing java options : -Dcom.sun.management.jmxremote.port=<some free port> -Dcom

问题 This is similar to Java thread dump: BLOCKED thread without "waiting to lock ...". Basically, I am seeing a BLOCKED thread but it has the lock it is waiting for: "pool-1-thread-60" prio=10 tid=0x00007fbf10017000 nid=0x210 waiting for monitor entry [0x00007fbed64e3000] java.lang.Thread.State: BLOCKED (on object monitor) at org.apache.log4j.Category.callAppenders(Category.java:204) - locked <0x0000000742444ad0> (a org.apache.log4j.Logger) at org.apache.log4j.Category.forcedLog(Category.java:391