XMF Configuration Parameters

The Extended Message Facility (XMF) component manages communication between the current coserver and all other coservers of Extended Parallel Server.

Depending on the size of the data to transfer to another coserver, the XMF chooses the appropriate buffer (SBUFFER, LBUFFER, or HBUFFER) to use. The XMF configuration parameters are used to set the buffer size on each coserver. In general, you should not change the default values of these configuration parameters.

For more information about XMF, refer to the chapter on monitoring data flow between coservers in your IBM Informix: Performance Guide.

Configuration Parameter

Description

ASYNCRQT

Specifies the number of outstanding receive requests used for each large endpoint on a coserver when you configure large communications buffers to send and receive data between coservers. See ASYNCRQT.

HBUFFER

Sets the huge buffer size. The default value for HBUFFER is 48 kilobytes.

LBUFFER

Sets the large buffer size. The default value for LBUFFER is 8 kilobytes.

SBUFFER

Sets the small buffer size. The default value for SBUFFER is 1 kilobyte.

SENDEPDS

Specifies the number of send endpoints per CPU virtual processor when you configure communications buffers to send and receive data between coservers. See SENDEPDS.