Tags
jvm tuning jstat jhat jmap gc
Env
- Spring Cloud Greenwich
- Spring Boot 2.1.5
- Java HotSpot(TM) 64-Bit Server VM (build 25.181-b13, mixed mode)
- STS (Spring Tool Suite) 4.1.1
- MackBook Pro Mojave
Objective
- Minimize Full GC, down to 0 if possible
Prerequisites
-
Build a jar
mvn -B -DskipTests clean package
Baseline - default jvm settings
-
Run
java -jar discovery-center-0.0.1-SNAPSHOT.jar -
jstat -gc
S0C S1C S0U S1U EC EU OC OU MC MU CCSC CCSU YGC YGCT FGC FGCT GCT 7168.0 8192.0 7160.1 0.0 494080.0 332080.5 82944.0 15609.6 46760.0 4 4845.5 6312.0 5953.5 12 0.063 2 0.118 0.181 -
Timing
5.814 = 2019-06-25 22:32:57.974 - 2019-06-25 22:33:03.788
1st try: still 1 FGC
-
Run
java -jar -Xms768m -Xmx768m -Xmn700m -XX:SurvivorRatio=10 -XX:+PrintGCDetails -XX:MetaspaceSize=50M discovery-center-0.0.1-SNAPSHOT.jar -
jstat
S0C S1C S0U S1U EC EU OC OU MC MU CCSC CCSU YGC YGCT FGC FGCT GCT 59392.0 59392.0 0.0 0.0 598016.0 264071.9 69632.0 23958.9 51200.0 48840.8 7040.0 6531.4 4 0.122 1 0.192 0.313 -
Timing
5.542 = 2019-06-25 22:46:48.423 - 2019-06-25 22:46:53.965
2nd try: 0 Full GC
-
Run
java -jar -Xms768m -Xmx768m -Xmn700m -XX:SurvivorRatio=10 -XX:+PrintGCDetails -XX:MetaspaceSize=80M discovery-center-0.0.1-SNAPSHOT.jar -
jstat
S0C S1C S0U S1U EC EU OC OU MC MU CCSC CCSU YGC YGCT FGC FGCT GCT 59392.0 59392.0 0.0 24209.6 598016.0 204594.4 69632.0 104.0 51584.0 49021.5 7040.0 6555.6 3 0.127 0 0.000 0.127 -
Timing
5.166 = 2019-06-25 22:57:28.061 - 2019-06-25 22:57:33.227
Heap dump
-
cmds
jmap -dump:format=b,file=discovery-center.dump $java-pid jhat -port 8888 discovery-center.dump
-
GUI Tools
Eclipse MAT, jconsole, jvisualvm, visualvm