Gc 日志不打印

Question

I pass the below value to jvms hosted on Jboss:

                            <option value="-XX:+PrintGCDetails"/>
                           <option value="-XX:+PrintGCTimeStamps"/>
                           <option value="-XX:+PrintGCDateStamps"/>
                           <option value="-XX:+UseGCLogFileRotation"/>
                           <option value="-XX:NumberOfGCLogFiles=50"/>
                           <option value="-XX:GCLogFileSize=50M"/>
                           <option value="-Xloggc:=/some/path/gc-%t.log"/>

But I dont' see any files with gc* under /some/path/ location.

I use JDK 8

Answer 1

The last option looks wrong, the = character does not belong there, so it should be:

                       <option value="-Xloggc:/some/path/gc-%t.log"/>

Please note that the option dependes on the JDK/JRE version:

• JDK up to version 8: -Xloggc:LOG_FILE_PATH
• JDK since version 9: -Xlog:gc:LOG_FILE_PATH , see https://openjdk.java.net/jeps/158