How to solve java.lang.OutOfMemoryError: unable to create new native thread?

Products	Versions
TIBCO ActiveMatrix BusinessWorks	-
Not Applicable	-

Description

Resolution:

Check Your Thread Stack Size :

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The first thing you might try in the checklist is reducing the stack size. The JVM has an interesting implementation, by which the more memory is allocated for the heap (not necessarily used by the heap), the less memory available in the stack, and since threads are made from the stack, in practice this means more “memory” in the heap sense (which is usually what people talk about) results in less threads being able to run concurrently.

To reduce the stack size, add “-Xss64kb” to the JVM options. I suggest you start with 64k, try the application, then if it doesn’t work (it will fail with a Java.lang.StackOverFlowError), increase the stack to 128k, then 256k, and so on. The default stack size is 8192k so there’s a wide range to test.

Checking your OS limits.conf :

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At operating system level, Linux users you can control the amount of resources (and in particular file descriptors) you are going to use in the limits.conf file or usint the ulimit command:

# vi /etc/security/limits.conf

testuser soft nofile 4096

testuser hard nofile 10240

# ulimit -Hn

10240

In either case, if the amount of file descriptors you are allowed to use is less the number of threads you are going to create, then this could be the issue.

Checking the number of Threads created :

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How do you check the number of threads created by your application ? You can do it in at least two ways:

$ ps -p PID -lfT | wc -l

The above shell will return the number of Lightweight Processes created for a Process indicated by the PID. This should match with the Thread Dump count generated by jstack:

$ jstack -l PID | grep tid | wc -l

Once that you have counted the number of threads, then you should verify that you are not hitting system limits, specified by the kernel.pid_max limit parameter. You can check this value by executing:

$ sysctl -a | grep kernel.pid_max

kernel.pid_max = 32768

Finally, you have also to check if your OS allows you enough processes for user. This can be checked through:

ulimit -a

core file size (blocks, -c) 0

data seg size (kbytes, -d) unlimited

scheduling priority (-e) 0

file size (blocks, -f) unlimited

pending signals (-i) 515005

max locked memory (kbytes, -l) 64

max memory size (kbytes, -m) unlimited

open files (-n) 4096

pipe size (512 bytes, -p) 8

POSIX message queues (bytes, -q) 819200

real-time priority (-r) 0

stack size (kbytes, -s) 10240

cpu time (seconds, -t) unlimited

max user processes (-u) 1024

virtual memory (kbytes, -v) unlimited

file locks (-x) unlimited

The default number of process per users is 1024 by default. So adding the following to your $HOME/.profile could solve the issue:

ulimit -u 50000 (or more according to your load )

Issue/Introduction

How to solve java.lang.OutOfMemoryError: unable to create new native thread?

Environment

Product: TIBCO ActiveMatrix BusinessWorks Version: OS: All Supported Operating Systems --------------------

Additional Information

44089, 38321, 37109

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