JAVA
Quick Tips
Stream (Java 8)
Check JVM default Heap size, Xmx and Xms
java -XX:+PrintFlagsFinal -version | egrep '(InitialHeapSize|MaxHeapSize)'
jstat
jstat -gcutil $PID 250 7
jstat utility attaches to PID, takes 7 samples at 250-millisecond intervals
jstat (Java8)
cd /usr/lib/jvm/java-1.8.0-openjdk.x86_64/bin
./jstat -gc $PID 1000
./jstat -gccapacity $PID 1000
Reference
- Java SE 6 Virtual Machine Garbage Collection Tuning
- Monitoring Java Garbage Collection Using jstat
- jstack
- Using top and jstack to find the Java thread that is hogging the CPU
- Analyzing Java Memory
- The jstat Utility
- Java Memory Model – Memory Management in Java
- Tuning Garbage Collection with Sun JDK
- Tune your JVM
- JVM Parameter SurvivorRatio
- JDK之jstat的用法
- [Java] 關於 Garbage Collection 的二三事(一)
- Java 8: From PermGen to Metaspace