Tomcat 8.5.29 throws EOFException with 500 Internal Server Error

Question

I'm trying to access spring endpoint in AWS-EKS environment, I'm not recreate this issue locally but in production logs we see lot 500 Internal Server Error with below EOF Exception logged at same time:

logtype: tomcat-server message: Servlet.service() for servlet [com.abc.platform.xservices.rest.abcApplication] in context with path [/something] threw exception [org.glassfish.jersey.server.ContainerException: java.io.EOFException: Unexpected EOF read on the socket] with root cause java.io.EOFException: Unexpected EOF read on the socket at org.apache.coyote.http11.Http11InputBuffer.fill(Http11InputBuffer.java:722) at org.apache.coyote.http11.Http11InputBuffer.access$300(Http11InputBuffer.java:40) at org.apache.coyote.http11.Http11InputBuffer$SocketInputBuffer.doRead(Http11InputBuffer.java:1072)

Any idea on why we see this in issue in production? Thanks.

Answer 1

It's an internal server error, which returns status code 500 in response

This may be caused by incorrect requests, but as well server code or overload may be the reason. If you have access to the server, check event logs.

See also

500 EOF when chunk header expected

Why might LWP::UserAgent be failing with '500 EOF'?

500 EOF instead of reponse status line in perl script

Apache 1.3 error - Unexpected EOF reading HTTP status - connectionreset

Error 500!

UPDATE On the other hand, if it's not response message, but a real exception, then it may be simply a bug, just like in old java And workaround may be putting getResponseCode() inside of try/catch and call second time on exception:

int responseCode = -1;
    try {
        responseCode = con.getResponseCode();
    } catch (IOException ex1) {
        //check if it's eof, if yes retrieve code again
        if (-1 != ex1.getMessage().indexOf("EOF")) {
            try {
                responseCode = con.getResponseCode();
            } catch (IOException ex2) {
                System.out.println(ex2.getMessage());
                // handle exception
            }
        } else {
            System.out.println(ex1.getMessage());
            // handle exception
        }
    }

Talking by connections number limit, read.