problems with too many ssl_read and ssl_write errors

[David Bowers via openssl-users]

  *   We have a server that has around  2025 clients connected at any instant.
  *   Our application creates a Server /Listener socket that then is converted 
into a Secure socket using OpenSSL library. This is compiled and built in a 
Windows x64 environment.  We also built the OpenSSL for the Windows. The 
Listener socket is created with a default backlog of 500. The Accept socket is 
non-blocking socket and waits for connections
  *   Every Client makes a regular blocking connection to the Server. The 
Server accepts the connection after which the Client socket is converted to a 
secure socket using the OpenSSL Library.
  *   The connections are coming at a rate of about 10 connections /second ?  
Not sure about this number.
  *   We are able to connect to all the clients in a few minutes and it stays 
like that for some time.  There constant exchange of messages between 
Server(COS) and clients without issues.
  *   The application logic is to keep trying to connect every timeout.
  *   After maybe a few hours/days we see the clients dropping connections.  
The logs indicate the SSL_Read or SSL_Write on the Server fails for a client 
with SSL_Error number 5 (SSL_ERROR_SYSCALL) and the equivalent Windows error of 
WSATimeOut.  We then observe the WSAECONNRESET as the Client closed connection. 
 We see this behavior for multiple sites.
  *   The number of Clients disconnected starts increasing and we see the logs 
in the Client where the server refuses any more connections form Clients 
(10061- WSAECONNREFUSED) There is nothing to indicate this state in the server 
logs. Our theory is the backlog is filled and Server refusing further 
connections.
  *   We are trying to find why we get the SSL_Read/SSL_Write Error as it a 
Blocking socket. We cannot use to a non-blocking socket due to platform and 
application limitation