Unexpected end of file from server

[BerksanAtes]

Describe the bug

Web service requests that are going trough proxy(IHS) with a low KeepAliveTimeout(3), fails with "java.net.SocketException: Unexpected end of file from server" for Liberty versions 2.0.0.8 and later.

Steps:

1. Requester sends a web service request
2. Keep alive timeout at the proxy is 3 seconds.
3. In 3 seconds, the proxy sends to a FIN packet to the requester.
4. If the requester sends another request just before the FIN packet, the request fails with "java.net.SocketException: Unexpected end of file from server"

Topology:

WebService requester/wlp --- forward proxy(IHS) --- WebService provider/wlp

If there is a stack trace, please include the FULL stack trace (without any [internal classes] lines in it). To find the full stack trace, you may need to check in $WLP_OUTPUT_DIR/messages.log

Caused by: java.net.SocketException: Unexpected end of file from server
        at sun.net.www.http.HttpClient.parseHTTPHeader(HttpClient.java:884)
        at sun.net.www.http.HttpClient.parseHTTP(HttpClient.java:709)
        at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1619)
        at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1524)
        at java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:491)
        at org.apache.cxf.transport.http.URLConnectionHTTPConduit$URLConnectionWrappedOutputStream$2.run(URLConnectionHTTPConduit.java:424)
        at org.apache.cxf.transport.http.URLConnectionHTTPConduit$URLConnectionWrappedOutputStream$2.run(URLConnectionHTTPConduit.java:420)
        at java.security.AccessController.doPrivileged(AccessController.java:747)
        at org.apache.cxf.transport.http.URLConnectionHTTPConduit$URLConnectionWrappedOutputStream.getResponseCode(URLConnectionHTTPConduit.java:420)
        at org.apache.cxf.transport.http.HTTPConduit$WrappedOutputStream.doProcessResponseCode(HTTPConduit.java:1659)
        at org.apache.cxf.transport.http.HTTPConduit$WrappedOutputStream.handleResponseInternal(HTTPConduit.java:1687)
        at org.apache.cxf.transport.http.HTTPConduit$WrappedOutputStream.handleResponse(HTTPConduit.java:1632)
        at org.apache.cxf.transport.http.HTTPConduit$WrappedOutputStream.close(HTTPConduit.java:1424)
        ... 41 more

Steps to Reproduce

1. Have Web Service consumer and provider on different Liberty servers
2. Configure IHS(IBM HTTP Server) as a forward proxy.
3. Set KeepAliveTimeout to 3
4. Set Listen port same as http.proxyPort at the client side
5. Start IHS and liberty
6. Open a new terminal window and run the tcpdump command.
7. Send a request curl to invoke Web Service consumer
8. After the request is completed, IHS will send back a FIN packet to client in 3 seconds.
9. Send another request by curl. This will fail on wlp 22.0.0.8 or later.

Expected behavior

Web Service should run trough proxy with success.

Diagnostic information:

• OpenLiberty Version: 22.0.0.8 and above
• Affected feature(s) : jaxws-2.2
• Java Version : Java(TM) SE Runtime Environment (8.0.6.5 - pap6480sr6fp5-20200111_02(SR6 FP5))
• server.xml configuration
• If it would be useful, upload the messages.log file found in $WLP_OUTPUT_DIR/messages.log

Additional context