Increase “Open Files Limit” for Traccar

Content
1. Error Log 
2. How to add some command for Linux system

1. Error Log 
I’m facing this kind problem when there are many Traccar client for androids has been keep sending the data to the server. It caused the Linux system to print this error log like below:

	Exception in thread "pool-4-thread-1" java.lang.InternalError: java.io.FileNotFoundException: /usr/java/jdk1.8.0_60/jre/lib/ext/cldrdata.jar (Too many open files)
	at sun.misc.URLClassPath$JarLoader.getResource(URLClassPath.java:1003)
	at sun.misc.URLClassPath.getResource(URLClassPath.java:212)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:365)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:362)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:361)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:411)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	at java.util.ResourceBundle$RBClassLoader.loadClass(ResourceBundle.java:503)
	at java.util.ResourceBundle$Control.newBundle(ResourceBundle.java:2640)
	at java.util.ResourceBundle.loadBundle(ResourceBundle.java:1501)
	at java.util.ResourceBundle.findBundle(ResourceBundle.java:1465)
	at java.util.ResourceBundle.getBundleImpl(ResourceBundle.java:1361)
	at java.util.ResourceBundle.getBundle(ResourceBundle.java:845)
	at java.util.logging.Level.computeLocalizedLevelName(Level.java:265)
	at java.util.logging.Level.getLocalizedLevelName(Level.java:324)
	at java.util.logging.SimpleFormatter.format(SimpleFormatter.java:165)
	at java.util.logging.StreamHandler.publish(StreamHandler.java:211)
	at java.util.logging.ConsoleHandler.publish(ConsoleHandler.java:116)
	at java.util.logging.Logger.log(Logger.java:738)
	at java.util.logging.Logger.doLog(Logger.java:765)
	at java.util.logging.Logger.logp(Logger.java:1041)
	at org.jboss.netty.logging.JdkLogger.warn(JdkLogger.java:80)
	at org.jboss.netty.channel.socket.nio.AbstractNioSelector.run(AbstractNioSelector.java:340)
	at org.jboss.netty.channel.socket.nio.NioServerBoss.run(NioServerBoss.java:42)
	at org.jboss.netty.util.ThreadRenamingRunnable.run(ThreadRenamingRunnable.java:108)
	at org.jboss.netty.util.internal.DeadLockProofWorker$1.run(DeadLockProofWorker.java:42)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:745)
	Caused by: java.io.FileNotFoundException: /usr/java/jdk1.8.0_60/jre/lib/ext/cldrdata.jar (Too many open files)
	at java.util.zip.ZipFile.open(Native Method)
	at java.util.zip.ZipFile.<init>(ZipFile.java:219)
	at java.util.zip.ZipFile.<init>(ZipFile.java:149)
	at java.util.jar.JarFile.<init>(JarFile.java:166)
	at java.util.jar.JarFile.<init>(JarFile.java:103)
	at sun.misc.URLClassPath$JarLoader.getJarFile(URLClassPath.java:893)
	at sun.misc.URLClassPath$JarLoader.access$700(URLClassPath.java:756)
	at sun.misc.URLClassPath$JarLoader$1.run(URLClassPath.java:838)
	at sun.misc.URLClassPath$JarLoader$1.run(URLClassPath.java:831)
	at java.security.AccessController.doPrivileged(Native Method)
	at sun.misc.URLClassPath$JarLoader.ensureOpen(URLClassPath.java:830)
	at sun.misc.URLClassPath$JarLoader.getResource(URLClassPath.java:1001)
	... 31 more

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2. How to add some command for Linux system
In Traccar Server Web, I had configured some configurations but it still caused the same problem but after I read the document in Traccar’s Site I found the Solution.

By default Traccar runs from root user account as a daemon (service), so you have to check limits for the root user. On most systems by default, the limit is around 1024 connections.

To increase the limit add following lines to "/etc/security/limits.conf":

root soft  nofile 50000

root hard  nofile 50000

Make sure you use number higher than your number of devices because when device reconnects it might consume two or even more connection for some period of time.

You type these comment to check your default value, it so small:

Command for Hard Limit

ulimit -Hn

Command for Soft Limit

ulimit -Sn

Below is the output from my server, it is the default value so you have to change it in order avoid open file limit on your server.

To change your configuration on your Linux system, please copy 2 lines of code below into file "limits.conf"  
Use this command: vi /etc/security/limits.conf to open the file and add these lines:

root soft  nofile 50000

root hard  nofile 50000

To check if it is effective or not, you have to log out from your remote and remote to it again and then type the old command :

ulimit -Hn

ulimit -Sn

result: