Configuring TCP Sockets

When attempting to handle a large number of transactions, under a scalable load, it may be necessary to increase the size of the TCP socket pool in order to avoid running out of TCP sockets. This problem can occur because your Windows system does not free the TCP socket resources quickly enough.

To increase the size of the socket pool by modifying the Windows Registry
  1. Open the Windows Registry.

  2. Open HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\TCPIP\Parameters and make the following changes:

    Add this DWORD name
    Set to
    TcpTimedWaitDelay Set to a low value, such as 1 (default: 30 seconds).
    MaxUserPort Set to a high value, such as 32768. (default: 5000).
  3. Open HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Afd\Parameters, and add the DWORD name DisableAddressSharing, set to a low value, such as 1.

Modifying TCP configurations in Solaris

In a Solaris environment, TCP/IP configuration changes are typically made using the "ndd" utility. The "ndd" utility can be used to 'get' (display) and 'set' (change) the TCP/IP driver configuration values.

To increase the size of the socket pool by modifying TCP/IP configurations in Solaris
  1. Enter the following to view the available set of commands:

    ndd /dev/tcp \?

  2. Make the following modifications:
    Change
    To
    tcp_conn_req_max_q A higher value, such as 1024
    tcp_time_wait_interval A lower value, such as 60000 or lower (the default is 240000)
    tcp_fin_wait_2_flush_interval A lower value, such as 67500 or lower (the default is 675000)
Related Topics
Bullet Configuring Your Run-time Environment
Bullet Configuring the Runtime Service
Bullet Updating MCS Server Information for Your Run-time Servers
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