io-buffer-size

Syntax

io-buffer-size = number_of_bytes

Description

Positive integer value that indicates the buffer size, in bytes, for low-level reads from and writes to a client.

Options

number_of_bytes

Positive integer value that indicates the buffer size, in bytes, for low-level reads from and writes to a client.

The minimum value is 1. WebSEAL does not impose a maximum value.

A small value (for instance, 10 bytes) can hurt performance by causing frequent calls to the low-level read/write APIs. Up to a certain point, larger values improve performance because they correspondingly reduce the calls to the low-level I/O functions.

However, the low-level I/O functions might have their own internal buffers, such as the TCP send and receive buffers. When io-buffer-size exceeds the size of those buffers, there is no longer any performance improvement because those functions read only part of the buffer at the time.

Reasonable values for io-buffer-size range from 1 - 16 kB. Values smaller than this range causes calling the low-level I/O functions too frequently. Values larger than this range wastes memory. A 2 MB I/O buffer size uses 4 MB for each worker thread that communicates with the client, since there is an input and output buffer.

Usage

This stanza entry is required.

Default value

4096