Resolution for “No buffer space available (maximum connections reached?): JVM_Bind” issue

I hit this issue recently which occurred on only one windows 7 host. The error was caused by this hard to guess reason (http://support.microsoft.com/kb/196271). The default number of ephemeral TCP ports is 5000. Sometimes this number may become less if the server has too many active client connections due to which the ephemeral TCP ports are all used up and in this case no more can be allocated to a new client connection request resulting in the below issue (for a Java application):

Caused by: java.net.SocketException: No buffer space available (maximum connections reached?): JVM_Bind

    at java.net.PlainSocketImpl.socketBind(Native Method)

    at java.net.PlainSocketImpl.bind(PlainSocketImpl.java:365)

    at java.net.Socket.bind(Socket.java:577)

    at com.sun.net.ssl.internal.ssl.BaseSSLSocketImpl.bind(BaseSSLSocketImpl.java:95)

    at com.sun.net.ssl.internal.ssl.SSLSocketImpl.bind(SSLSocketImpl.java:45)

    at com.sun.net.ssl.internal.ssl.SSLSocketImpl.<init>(SSLSocketImpl.java:399)

    at com.sun.net.ssl.internal.ssl.SSLSocketFactoryImpl.createSocket(SSLSocketFactoryImpl.java:123)

    at org.apache.commons.httpclient.contrib.ssl.EasySSLProtocolSocketFactory.createSocket(EasySSLProtocolSocketFactory.java:183)

    at org.apache.commons.httpclient.HttpConnection.open(HttpConnection.java:707)

    at org.apache.commons.httpclient.MultiThreadedHttpConnectionManager$HttpConnectionAdapter.open(MultiThreadedHttpConnectionManager.java:1361)

    at org.apache.commons.httpclient.HttpMethodDirector.executeWithRetry(HttpMethodDirector.java:387)

    at org.apache.commons.httpclient.HttpMethodDirector.executeMethod(HttpMethodDirector.java:171)

    at org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:397)

The resolution is to open the registry editor and locate the registry subkey:HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters and add a new entry as shown below:
or
Ctrl+r --> Enter regedit  --->Choose HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters and add below entry
(Right click on window choose  new -->DWORD(32 bit) values) and enter below values

Value Name: MaxUserPort
Value Type: DWORD
Value data: 65534