We have recently upgraded Jenkins core from 1.6.2 to 2.7.2 .
From then we are regularly facing "too many open files issue " and our Jenkins Master crashes off .
From the logs we found that all the pluigns and Nodes connected are causing this , Could you kindly help us resolve this issue .

3-Oct-2016 10:15:38.940 INFO [PeriodicBackup thread] hudson.model.AsyncPeriodicWork$1.run Started PeriodicBackup
13-Oct-2016 10:15:38.941 WARNING [PeriodicBackup thread] org.jenkinsci.plugins.periodicbackup.PeriodicBackup.execute Cron is not defined.
13-Oct-2016 10:15:38.941 INFO [PeriodicBackup thread] hudson.model.AsyncPeriodicWork$1.run Finished PeriodicBackup. 1 ms
13-Oct-2016 10:16:27.845 INFO Executor #0 for NBSUAT01_FORMS : executing NBS/01_Start #207 hudson.model.Run.execute NBS/01_Start #207 main build action completed: SUCCESS
Too many open files
147 descriptors are open
#1 /appl/apache-tomcat/8.0.17/webapps/jenkins/WEB-INF/lib/commons-lang-2.6.jar by thread:Computer.threadPoolForRemoting 849 for PRD01_FORMS on Thu Oct 13 10:16:27 BST 2016
at java.util.zip.ZipFile.<init>(ZipFile.java:151)
at java.util.jar.JarFile.<init>(JarFile.java:166)
at java.util.jar.JarFile.<init>(JarFile.java:103)
at sun.net.www.protocol.jar.URLJarFile.<init>(URLJarFile.java:93)
at sun.net.www.protocol.jar.URLJarFile.getJarFile(URLJarFile.java:69)
at sun.net.www.protocol.jar.JarFileFactory.get(JarFileFactory.java:99)
at sun.net.www.protocol.jar.JarURLConnection.connect(JarURLConnection.java:122)
at sun.net.www.protocol.jar.JarURLConnection.getInputStream(JarURLConnection.java:150)
at java.net.URL.openStream(URL.java:1038)
at hudson.remoting.RemoteClassLoader$ClassLoaderProxy.fetch3(RemoteClassLoader.java:810)
at sun.reflect.GeneratedMethodAccessor1000.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at hudson.remoting.RemoteInvocationHandler$RPCRequest.perform(RemoteInvocationHandler.java:884)
at hudson.remoting.Request$2.run(Request.java:332)
at hudson.remoting.InterceptingExecutorService$1.call(InterceptingExecutorService.java:68)
at org.jenkinsci.remoting.CallableDecorator.call(CallableDecorator.java:18)
at hudson.remoting.CallableDecoratorList$1.call(CallableDecoratorList.java:21)
at jenkins.util.ContextResettingExecutorService$2.call(ContextResettingExecutorService.java:46)