I need a way to be able to trigger full GC from a linux console script on ubuntu. I know this is extremely bad practice but without going into too much detail this keeps my server running, This is only meant for 1 or 2 days while I fix the actual problem, so I don't have to wake up in the night and perform manual GC through jconsole or jvisualvm.
我需要一种能够从ubuntu上的linux控制台脚本触发完整GC的方法。我知道这是非常糟糕的做法，但没有太多细节，这使我的服务器保持运行，这只是在我解决实际问题的1或2天，所以我不必在夜间醒来并执行通过jconsole或jvisualvm手动GC。
Alternatively I have to make a mouse script that clicks the button every 3-4 hours or so which is even worse.
或者，我必须制作一个鼠标脚本，每3-4小时左右点击一次按钮，这更糟糕。
Please help.
请帮忙。
4 个解决方案
#1
11
If you can have your application start a JMX server (which I believe is implied from your use of jconsole/jvisualvm), then you can invoke the Memory MBean's gc operation via command-line utilities.
如果您可以让您的应用程序启动JMX服务器（我认为这是使用jconsole / jvisualvm所暗示的），那么您可以通过命令行实用程序调用Memory MBean的gc操作。
Firstly you'll need some kind of command-line JMX client. I've used this one in the past for simple command-line invocations and it worked fine. (Edit: In fact I used it just now to test out the following command, and it invoked GC successfully on a local Tomcat process)
首先，您需要某种命令行JMX客户端。我过去使用过这个用于简单的命令行调用，并且工作正常。 （编辑：事实上我刚刚用它来测试以下命令，并在本地Tomcat进程上成功调用了GC）
Then you'll need to work out the command to trigger garbage collection. I think this should work (you'll of course need to change hosts/ports/credentials as appropriate):
然后你需要找出命令来触发垃圾收集。我认为这应该可行（您当然需要根据需要更改主机/端口/凭据）：
java -jar cmdline-jmxclient-X.X.jar - localhost:8081 java.lang:type=Memory gc
Finally, you can schedule invocation of this command via cron or equivalent.
最后，您可以通过cron或等效计划调用此命令。
Voila!
瞧！
#2
7
If you have oracle jvm 1.7, you can use jcmd to list the jvm PIDs, and then jcmd <pid> GC.run to GC.
如果你有oracle jvm 1.7，你可以使用jcmd列出jvm PID，然后使用jcmd
jcmd <pid> help will show you what other commands are available.
jcmd
#3
3
jcmd <pid> GC.run
Example:
例：
jcmd 20350 GC.run
#4
-2
It's not bad practice, it is impossible - even for the java application being executed by the JVM. There is a gc() call available but even it is only a hint to the JVM to run garbage collection. From the console, there is normally no way to influence the JVM while it is running.
实践并不坏 - 这是不可能的 - 即使是由JVM执行的Java应用程序也是如此。有一个gc（）调用可用，但即使它只是一个提示JVM运行垃圾收集。从控制台，通常无法在JVM运行时影响它。
Some has asked this question for the Windows platform, see question How to request JVM garbage collection (not from code) when run from Windows command-line
有些人已经为Windows平台提出了这个问题，请参阅问题从Windows命令行运行时如何请求JVM垃圾回收（而不是代码）
You might check out the JVM arguments for stack/heap sizes (both min and max). There are lots of tweaks you can do in that area but they are mostly specific to the JVM you are using.
您可以查看堆栈/堆大小（最小和最大）的JVM参数。您可以在该区域进行大量调整，但它们主要针对您正在使用的JVM。
JVM performance tuning for large applications
针对大型应用程序的JVM性能调优
#1
11
If you can have your application start a JMX server (which I believe is implied from your use of jconsole/jvisualvm), then you can invoke the Memory MBean's gc operation via command-line utilities.
如果您可以让您的应用程序启动JMX服务器（我认为这是使用jconsole / jvisualvm所暗示的），那么您可以通过命令行实用程序调用Memory MBean的gc操作。
Firstly you'll need some kind of command-line JMX client. I've used this one in the past for simple command-line invocations and it worked fine. (Edit: In fact I used it just now to test out the following command, and it invoked GC successfully on a local Tomcat process)
首先，您需要某种命令行JMX客户端。我过去使用过这个用于简单的命令行调用，并且工作正常。 （编辑：事实上我刚刚用它来测试以下命令，并在本地Tomcat进程上成功调用了GC）
Then you'll need to work out the command to trigger garbage collection. I think this should work (you'll of course need to change hosts/ports/credentials as appropriate):
然后你需要找出命令来触发垃圾收集。我认为这应该可行（您当然需要根据需要更改主机/端口/凭据）：
java -jar cmdline-jmxclient-X.X.jar - localhost:8081 java.lang:type=Memory gc
Finally, you can schedule invocation of this command via cron or equivalent.
最后，您可以通过cron或等效计划调用此命令。
Voila!
瞧！
#2
7
If you have oracle jvm 1.7, you can use jcmd to list the jvm PIDs, and then jcmd <pid> GC.run to GC.
如果你有oracle jvm 1.7，你可以使用jcmd列出jvm PID，然后使用jcmd
jcmd <pid> help will show you what other commands are available.
jcmd
#3
3
jcmd <pid> GC.run
Example:
例：
jcmd 20350 GC.run
#4
-2
It's not bad practice, it is impossible - even for the java application being executed by the JVM. There is a gc() call available but even it is only a hint to the JVM to run garbage collection. From the console, there is normally no way to influence the JVM while it is running.
实践并不坏 - 这是不可能的 - 即使是由JVM执行的Java应用程序也是如此。有一个gc（）调用可用，但即使它只是一个提示JVM运行垃圾收集。从控制台，通常无法在JVM运行时影响它。
Some has asked this question for the Windows platform, see question How to request JVM garbage collection (not from code) when run from Windows command-line
有些人已经为Windows平台提出了这个问题，请参阅问题从Windows命令行运行时如何请求JVM垃圾回收（而不是代码）
You might check out the JVM arguments for stack/heap sizes (both min and max). There are lots of tweaks you can do in that area but they are mostly specific to the JVM you are using.
您可以查看堆栈/堆大小（最小和最大）的JVM参数。您可以在该区域进行大量调整，但它们主要针对您正在使用的JVM。
JVM performance tuning for large applications
针对大型应用程序的JVM性能调优