jvm

问题 I built a simple application using Springboot.The ZGC garbage collector I use when deploying to a Linux server USES a lot of memory..I tried to limit the maximum heap memory to 500MB with Xmx500m, but the JAVA program still used more than 1GB. When I used the G1 collector, it only used 350MB.I don't know why, is this a BUG of JDK11?Or do I have a problem with my boot parameters? ####Runtime environment operating system : CentOS Linux release 7.8.2003 JDK version : jdk11 springboot version :

问题 I built a simple application using Springboot.The ZGC garbage collector I use when deploying to a Linux server USES a lot of memory..I tried to limit the maximum heap memory to 500MB with Xmx500m, but the JAVA program still used more than 1GB. When I used the G1 collector, it only used 350MB.I don't know why, is this a BUG of JDK11?Or do I have a problem with my boot parameters? ####Runtime environment operating system : CentOS Linux release 7.8.2003 JDK version : jdk11 springboot version :

问题 I am creating a docker image using below configuration. Once image is ready i want to pass JAVA_OPTS to my docker container, so it can be passed to my spring boot application. Whenever i try to bring up the container i am getting "runtime create failed: container_linux.go:348: starting container process caused "exec: \"java $JAVA_OPTS\": executable file not found in $PATH": unknown" error. Am i missing something ? Any help is really appreciated Dockerfile FROM openjdk:8-jdk-alpine LABEL

问题 I am creating a docker image using below configuration. Once image is ready i want to pass JAVA_OPTS to my docker container, so it can be passed to my spring boot application. Whenever i try to bring up the container i am getting "runtime create failed: container_linux.go:348: starting container process caused "exec: \"java $JAVA_OPTS\": executable file not found in $PATH": unknown" error. Am i missing something ? Any help is really appreciated Dockerfile FROM openjdk:8-jdk-alpine LABEL

问题 The Java memory model guarantees a happens-before relationship between an object's construction and finalizer: There is a happens-before edge from the end of a constructor of an object to the start of a finalizer (§12.6) for that object. As well as the constructor and the initialization of final fields: An object is considered to be completely initialized when its constructor finishes. A thread that can only see a reference to an object after that object has been completely initialized is

问题 The Java memory model guarantees a happens-before relationship between an object's construction and finalizer: There is a happens-before edge from the end of a constructor of an object to the start of a finalizer (§12.6) for that object. As well as the constructor and the initialization of final fields: An object is considered to be completely initialized when its constructor finishes. A thread that can only see a reference to an object after that object has been completely initialized is

问题 Is there a cheaper method call in Java 9+ which keeps its safepoint? The JVM removes safepoints at runtime to improve efficiency however this can make profiling and monitoring the code more difficult. For this reason, we deliberately add trivial calls in carefully selected places to ensure there is a safepoint present. public static void safepoint() { if (IS_JAVA_9_PLUS) Thread.holdsLock(""); // 100 ns on Java 11 else Compiler.enable(); // 5 ns on Java 8 } public static void optionalSafepoint

问题 Is there a cheaper method call in Java 9+ which keeps its safepoint? The JVM removes safepoints at runtime to improve efficiency however this can make profiling and monitoring the code more difficult. For this reason, we deliberately add trivial calls in carefully selected places to ensure there is a safepoint present. public static void safepoint() { if (IS_JAVA_9_PLUS) Thread.holdsLock(""); // 100 ns on Java 11 else Compiler.enable(); // 5 ns on Java 8 } public static void optionalSafepoint

问题 Is there a cheaper method call in Java 9+ which keeps its safepoint? The JVM removes safepoints at runtime to improve efficiency however this can make profiling and monitoring the code more difficult. For this reason, we deliberately add trivial calls in carefully selected places to ensure there is a safepoint present. public static void safepoint() { if (IS_JAVA_9_PLUS) Thread.holdsLock(""); // 100 ns on Java 11 else Compiler.enable(); // 5 ns on Java 8 } public static void optionalSafepoint

问题 I would like to know about the various options for distributing a Java application. I know that you can Distribute the Source Code and let users compile it themselves, or provide make files, etc.. Package it into a JAR, and have self extracting archives and (I'm sure, myriad other ways) I'm hoping for some explanations about the most common options (and one's I haven't thought of) and in particular, do they require a user to have a JVM, or can it be bundled with one - personally I'm not too