影响因素
jvm配置 -Xms -Xmx -Xss

-Xss
the stack size for each thread

-Xmx1024m -Xms1024m  -Xss128k

jcmd 15611 VM.flags -all

intx ThreadStackSize  = 1024    {pd product}


系统限制

max_user_process（ulimit -u）

/proc/sys/kernel/pid_max
/proc/sys/kernel/thread-max
/proc/sys/vm/max_map_count


cat /proc/sys/kernel/pid_max
32768  (32K)
ulimit -u
7282
cat /proc/sys/vm/max_map_count
65530

cat /proc/sys/kernel/thread-max
cat: /proc/sys/kernel/thread-max: 没有那个文件或目录





MaxThreadCountTest

https://gitee.com/dyyx/hellocode/blob/master/src/MaxThreadCountTest.java


java MaxThreadCountTest
java.lang.OutOfMemoryError: unable to create new native thread

java  -Xss128k MaxThreadCountTest
The stack size specified is too small, Specify at least 228k

java  -Xss256k MaxThreadCountTest


java MaxThreadCountTest
java.lang.OutOfMemoryError: unable to create new native thread
8005


ulimit -u
10000
ulimit -u 60000
-bash: ulimit: max user processes: 无法修改 limit 值: 不允许的操作

sudo ulimit -n 65535
sudo: ulimit: command not found

用以下方式修改 !!!

sudo sh -c "ulimit -u 60000 && exec su $LOGNAME"

ulimit is a shell builtin like cd, not a separate program. 
sudo looks for a binary to run, but there is no ulimit binary, which is why you get the error message. 
You need to run it in a shell.



/opt/jdk1.8.0_171/bin/java  MaxThreadCountTest
 
java.lang.OutOfMemoryError: unable to create new native thread
63541





 jvm参数查看  
 Linux常用优化设置