tomcat中的错误“打开的文件太多” [英] Error in tomcat "too many open files"
问题描述
我有一个在tomcat上运行的应用程序，有时我有以下错误：
I have an application running on tomcat and sometimes I have the error below:
SEVERE: Socket accept failed
java.net.SocketException: Too many open files
at java.net.PlainSocketImpl.socketAccept(Native Method)
at java.net.AbstractPlainSocketImpl.accept(AbstractPlainSocketImpl.java:398)
at java.net.ServerSocket.implAccept(ServerSocket.java:522)
at java.net.ServerSocket.accept(ServerSocket.java:490)
at org.apache.tomcat.util.net.DefaultServerSocketFactory.acceptSocket(DefaultServerSocketFactory.java:60)
at org.apache.tomcat.util.net.JIoEndpoint$Acceptor.run(JIoEndpoint.java:216)
at java.lang.Thread.run(Thread.java:722)
....
SEVERE: Error processed default web.xml named conf/web.xml at /local/myApp/apache-tomcat/conf/web.xml
java.io.FileNotFoundException: /local/myApp/apache-tomcat/conf/web.xml (Too many open files)
at java.io.FileInputStream.open(Native Method)
at java.io.FileInputStream.<init>(FileInputStream.java:138)
at org.apache.catalina.startup.ContextConfig.getWebXmlSource(ContextConfig.java:1838)
at org.apache.catalina.startup.ContextConfig.getGlobalWebXmlSource(ContextConfig.java:1745)
at org.apache.catalina.startup.ContextConfig.getDefaultWebXmlFragment(ContextConfig.java:1418)
at org.apache.catalina.startup.ContextConfig.webConfig(ContextConfig.java:1253)
at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:878)
at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:369)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119)
at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5269)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.StandardContext.reload(StandardContext.java:3926)
at org.apache.catalina.loader.WebappLoader.backgroundProcess(WebappLoader.java:426)
at org.apache.catalina.core.ContainerBase.backgroundProcess(ContainerBase.java:1345)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1530)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1540)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1540)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.run(ContainerBase.java:1519)
at java.lang.Thread.run(Thread.java:722)
我检查打开文件的限制，它是1024但是当我用lsof检查应用程序的打开文件数量接近200时，如果没有达到限制，为什么会这样呢？
我应该增加限额吗？有没有其他理由得到这个错误？
让服务再次正常运行的唯一方法就是重新启动tomcat，还有另一种方法可以恢复正常吗？
I check the limits of the open files and it's 1024 but when I check the number of open files of the application with lsof it's nearly 200, why this happen if it does not reach the limit? Should I increase the limit? Is there any other reason to get this error? The only way to get the service running correctly again, it's restarting the tomcat, is there another way of getting back to normal?
提前致谢。
编辑：
这是处理doPost方法的servlet，一开始我没有关闭每一个流，可以吗是吗？我添加了finally语句：
EDIT: Here is the servlet which process the doPost method, at the beginning I didn't close every stream, could it be that? I added the finally statement for doing that:
InputStream is = null;
DataInputStream dis = null;
OutputStream os = null;
DataOutputStream dos = null;
String paramName = "";
try {
os = response.getOutputStream();
is = request.getInputStream();
dis = new DataInputStream(is);
dos = new DataOutputStream(os);
.....
}catch (Throwable e) {
LOGGER.error(e.getMessage());
} finally {
if (dis != null) {
dis.close();
}
else if(is != null) {
is.close();
}
if (dos != null) {
dos.close();
}
else if( os != null) {
os.close();
}
}
EDIT2：
在做了一些测试之后，我意识到如果我首先关闭DataInputStream然后关闭InputStream，我会在通信的另一部分得到消息之前的数字（我不知道为什么）。我改变了关闭流的顺序，似乎一切都没问题。但我仍然有问题。有什么想法吗？
After making some testing I realize that if I close first the DataInputStream and then the InputStream, I get in the other part of the communication a number before the message(I don't know why). I changed the order of closing the stream and it seems that everything it's ok. But I still have the problem. Any idea?
finally {
if(is != null) {
try {
is.close();
} catch (IOException e) {
LOGGER.error(e.getMessage());
}
}
if (dis != null) {
try {
dis.close();
} catch (IOException e) {
LOGGER.error(e.getMessage());
}
}
if(os != null) {
try {
os.close();
} catch (IOException e) {
LOGGER.error(e.getMessage());
}
}
if (dos != null) {
try {
dos.close();
} catch (IOException e) {
LOGGER.error(e.getMessage());
}
}
}
推荐答案
执行以下操作以获取tomcat7的pid（例如1234）
Do the following to get the pid, say 1234, of tomcat7
ps aux |grep tomcat7
然后执行
cat / proc / 1234 / limits 读取如下行：
最大打开文件16384 16384个文件
这些是Tomcat允许的最大打开文件数。要增加它，请按照以下说明操作
These are the maximum number of open files that are allowed by Tomcat. To increase it, follow the instructions below
这篇关于tomcat中的错误“打开的文件太多”的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
