From: Evan Hunt Date: Mon, 17 May 2021 16:34:08 +0000 (-0700) Subject: clarify buffer size options X-Git-Tag: v9.17.14~53^2 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=05985f68891c304a6161f27475f5b48d41d2b600;p=thirdparty%2Fbind9.git clarify buffer size options the documentation for {udp,tcp}-{send,receive}-buffer options was not complete. also revised for grammar. --- diff --git a/doc/arm/reference.rst b/doc/arm/reference.rst index 073ec17cd73..e8c348846c2 100644 --- a/doc/arm/reference.rst +++ b/doc/arm/reference.rst @@ -3586,22 +3586,26 @@ Tuning milliseconds. ``tcp-recv-buffer``; ``udp-recv-buffer`` - These options control the operating system receiving network buffer sizes for - TCP and UDP respectively. Buffering on the operating system level can - prevent packet drops during short spikes, but if the value is set too large - it could clog up a running server with outstanding queries that have already - timeouted. The default is ``0`` which means to use the operating system - default value. The operating system caps the maximum value that the user can - set here. + These options control the operating system's receive buffer sizes + (``SO_RCVBUF``) for TCP and UDP sockets respectively. Buffering at + the operating system level can prevent packet drops during brief load + spikes, but if the value is set too high, it could clog a running server + with outstanding queries that have already timed out. The default is + ``0``, which means the operating system's default value should be used. + The minimum configurable value is ``4096``; any nonzero value lower than + that will be silently raised. The maximum value is determined by the + kernel, and values exceeding the maximum will be silently reduced. ``tcp-send-buffer``; ``udp-send-buffer`` - These options control the operating system sending network buffer sizes for - TCP and UDP respectively. Buffering on the operating system level can - prevent packet drops during short spikes, but if the value is set too large - it could clog up a running server with outstanding queries that have already - timeouted. The default is ``0`` which means to use the operating system - default value. The operating system caps the maximum value that the user can - set here. + These options control the operating system's send buffer sizes + (``SO_SNDBUF``) for TCP and UDP sockets respectively. Buffering at the + operating system level can prevent packet drops during brief load + spikes, but if the value is set too high, it could clog a running server + with outstanding queries that have already timed out. The default is + ``0``, which means the operating system's default value should be used. + The minimum configurable value is ``4096``; any nonzero value lower than + that will be silently raised. The maximum value is determined by the + kernel, and values exceeding the maximum will be silently reduced. .. _builtin: