JVM_性能优化案例:调整堆大小提高服务的吞吐量

调整堆大小提高服务的吞吐量

修改tomcatJVM配置
生产环境下，Tomcat并不建议直接在catalina.sh里配置变量，而是写在与catalina同级目录（bin目录）下的setenv.sh里。

初始配置
setenv.sh文件中写入（大小根据自己情况修改）：setenv.sh内容如下：

export CATALINA_OPTS="$CATALINA_OPTS -Xms30m"
export CATALINA_OPTS="$CATALINA_OPTS -XX:SurvivorRatio=8"
export CATALINA_OPTS="$CATALINA_OPTS -Xmx30m"
export CATALINA_OPTS="$CATALINA_OPTS -XX:+UseParallelGC"
export CATALINA_OPTS="$CATALINA_OPTS -XX:+PrintGCDetails"
export CATALINA_OPTS="$CATALINA_OPTS -XX:MetaspaceSize=64m"
export CATALINA_OPTS="$CATALINA_OPTS -XX:+PrintGCDateStamps"
export CATALINA_OPTS="$CATALINA_OPTS -Xloggc:/opt/module/apache-tomcat-8.5.88/logs"

查看日志
其中存在大量的Full GC日志，查看一下我们Jmeter汇总报告

发现触发了一次gc

接下来我们测试另外一组数据，增加初始化和最大内存：

export CATALINA_OPTS="$CATALINA_OPTS -Xms120m"
export CATALINA_OPTS="$CATALINA_OPTS -XX:SurvivorRatio=8"
export CATALINA_OPTS="$CATALINA_OPTS -Xmx120m"
export CATALINA_OPTS="$CATALINA_OPTS -XX:+UseParallelGC"
export CATALINA_OPTS="$CATALINA_OPTS -XX:+PrintGCDetails"
export CATALINA_OPTS="$CATALINA_OPTS -XX:MetaspaceSize=64m"
export CATALINA_OPTS="$CATALINA_OPTS -XX:+PrintGCDateStamps"
export CATALINA_OPTS="$CATALINA_OPTS -Xloggc:/opt/module/apache-tomcat-8.5.88/logs"

发现没有触发gc