Tomcat 7 throwing frequent java.net.SocketException: Connection reset

Question

I am using Tomcat 7 and am getting frequent connection reset errors,

org.apache.coyote.http11.Http11Processor - Error parsing HTTP request header

java.net.SocketException: Connection reset
    at java.net.SocketInputStream.read(SocketInputStream.java:189)
    at java.net.SocketInputStream.read(SocketInputStream.java:121)
    at org.apache.coyote.http11.InternalInputBuffer.fill(InternalInputBuffer.java:516)
    at org.apache.coyote.http11.InternalInputBuffer.fill(InternalInputBuffer.java:501)
    at org.apache.coyote.http11.InternalInputBuffer.parseRequestLine(InternalInputBuffer.java:98)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:931)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
    at java.lang.Thread.run(Thread.java:722)

and at times, though not frequently "Unexpected EOF read on the socket",

org.apache.coyote.http11.Http11Processor - Error parsing HTTP request header

java.io.EOFException: Unexpected EOF read on the socket
    at org.apache.coyote.http11.InternalInputBuffer.parseRequestLine(InternalInputBuffer.java:99)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:931)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
    at java.lang.Thread.run(Thread.java:722)

From what i have read through, both seem to indicate that the client might have possibly abruptly closed the connection, while the server is reading it, resulting into a reset and/or EOF.

Are there any other reasons anyone can think of or have encountered. Also if both exceptions originate from the same problem, how is the frequency so varied, i get about 100 connection resets to say 5 EOF's.

Thanks

If tomcat is exposed to the internet it might also be due to some worms/port scanner that attacks random IPs. You could investigate by checking the tomcat access log and the origin IP. Monitoring tools (nagios and others) use sometimes poor check that just open/close a socket to check service availability, it can result in this kind of log messages. — nomoa, Oct 29 '14 at 10:44

score 2 · Accepted Answer · answered Nov 03 '14 at 05:59

More investigations and Wireshark dumps reveal, other than the actual load, 2 other things, show up, one is the load balancer which does a regular heartbeat check and another is a network monitoring script that again does a frequent pings.

So these seem to be the ones pinging and breaking the connections. So when we were monitoring a passive server which is again behind the LB and would too get pinged by the network monitoring script, but no production load. It too showed up the same exceptions that we saw on the active server with load. That confirmed the above observations. So one we can either ignore these or alter the monitoring script to wait for the responses from the server.

Tomcat 7 throwing frequent java.net.SocketException: Connection reset

1 Answers1