Database Administrator's Guide

COMPATIBILITY TCPIP_CHECK_DEAD_CLIENTS

COMPATIBILITY TCPIP_CHECK_DEAD_CLIENTS

With the COMPATIBILITY TCPIP_CHECK_DEAD_CLIENTS keyword in the Server configuration, the FairCom DB Server uses an older method to detect when a TCP/IP client has dropped, using the interval set by the DEAD_CLIENT_INTERVAL keyword. Every time interval, the client connection socket is rechecked to ensure that it is still a valid communications channel. If a connection is found to be invalid, the Server terminates the connection.

The FairCom DB Server normally recognizes when a client disconnects. However, the Server relies on a chain of events controlled by the operating system to recognize the disconnection. The client computer must notify the Server host computer that the connection has been dropped. For example: When a user closes an application, the socket is closed by the operating system, which sends a message to the Server host machine. However, if the network connection is temporarily interrupted or if the client machine is powered down suddenly, this message is not sent and the Server host machine can’t recognize that the client connection has dropped.

See Also:

• SESSION_TIMEOUT under Miscellaneous Control
  

  SESSION_TIMEOUT <seconds>

  The SESSION_TIMEOUT option forces TCP/IP connections to be removed after the specified number of seconds has elapsed without activity. This option has been verified on Windows, Linux, and Mac OS X.

  History

  In V11 and later:

  For 64-bit FairCom DB servers, a timeout allows each thread to detect and perform its own disconnection in case of a timeout.

  • If SESSION_TIMEOUT is negative, it is ignored.
  • If SESSION_TIMEOUT is less than 5, it is set to 5 so that the minimum SESSION_TIMEOUT value is 5 seconds.

  In V11.6.1 and later, SESSION_TIMEOUT also applies to SQL connections.

  Default: No timeout

• DEAD_CLIENT_INTERVAL