Java Startup command optimization

Java-xms256m-xmx1024m-xss256k-jar Doors.jar > Doorlog.txt 2>&1 &

Problem description

The Java program throws the java.lang.OutOfMemoryError:unable to create new native thread as follows:

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2. Java.lang.OutOfMemoryError:unable to create new native thread
4. At Java.lang.Thread.start0 (Native Method)
6. At Java.lang.Thread.start (Thread.java:691)
8. At Java.util.concurrent.ThreadPoolExecutor.addWorker (Threadpoolexecutor.java:949)
10. At Java.util.concurrent.ThreadPoolExecutor.processWorkerExit (Threadpoolexecutor.java:1017)
12. At Java.util.concurrent.ThreadPoolExecutor.runWorker (Threadpoolexecutor.java:1163)
14. At Java.util.concurrent.threadpoolexecutor$worker.run (Threadpoolexecutor.java:615)
16. At Java.lang.Thread.run (Thread.java:722)

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1. caused By:java.lang.OutOfMemoryError
2. At Java.util.zip.ZipFile.open (Native Method)
3. At Java.util.zip.zipfile.<init> (Zipfile.java:214)
4. At Java.util.zip.zipfile.<init> (Zipfile.java:144)
5. At Java.util.jar.jarfile.<init> (Jarfile.java:153)
6. At Java.util.jar.jarfile.<init> (Jarfile.java:117)

From the JVM level to solve

Reduce the size of the thread stack

The JVM default thread stack size is 1024, so that when threads cause native virtual memory to be exhausted, it is actually sufficient when the size of the thread stack is 128K or 256K, so if we explicitly specify thread Stack is 128K or 256K, specific use-Xss，例如在JVM启动的JVM_OPT中添加如下配置

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1. -xss128k

Reduce the size of the initial allocation of the heap or PermGen

If the JVM starts with the following configuration in the Jvm_opt

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1. -xms1303m-xmx1303m-xx:permsize=256m-xx:maxpermsize=256m

We can delete or reduce the configuration of the initialization minimum value, as follows

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1. -xms256m-xmx1303m-xx:permsize=64m-xx:maxpermsize=256m

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1. -xmx1303m-xx:maxpermsize=256m

升级JVM到最新的版本

The latest version of the JVM generally does better in memory optimization, and upgrading the JVM to the latest version may alleviate the problem of testing

从操作系统层面去解决 使用64位操作系统

如果使用32位操作系统遇到unable to create new native thread，建议使用64位操作系统

Increase the OS's limit on threads

Set Nofile and Nproc in the Linux operating system, specific edits/etc/security/limits.conf添加如下：

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1. Soft Nofile 2048
2. Hard Nofile 8192

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1. Soft Nproc 2048
2. Hard Nproc 8192

If you are using red Hat Enterprise Linux 6, edit/etc/security/limits.d/90-nproc.conf，添加如下配置：

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1. # cat/etc/security/limits.d/90-nproc.conf
2. * Soft Nproc 1024
3. Root Soft Nproc Unlimited
5. User-nproc 2048

Java Startup command optimization