diff options
| author | Susant Sahani <susant@redhat.com> | 2014-08-14 23:06:12 +0530 |
|---|---|---|
| committer | Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl> | 2014-08-14 19:55:44 -0400 |
| commit | cc567c9beace114554f7e7f50c3a5181cc44a07d (patch) | |
| tree | 749ee36446a80a0ad710c73f7677c3719fbbb277 /man | |
| parent | 209e9dcd7b2f23b68ff93bf20fad025bc03219ac (diff) | |
socket: Add support for TCP defer accept
TCP_DEFER_ACCEPT Allow a listener to be awakened only when data
arrives on the socket. If TCP_DEFER_ACCEPT set on a server-side
listening socket, the TCP/IP stack will not to wait for the final
ACK packet and not to initiate the process until the first packet
of real data has arrived. After sending the SYN/ACK, the server will
then wait for a data packet from a client. Now, only three packets
will be sent over the network, and the connection establishment delay
will be significantly reduced.
Diffstat (limited to 'man')
| -rw-r--r-- | man/systemd.socket.xml | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/man/systemd.socket.xml b/man/systemd.socket.xml index 5efb398b0..448390583 100644 --- a/man/systemd.socket.xml +++ b/man/systemd.socket.xml @@ -546,6 +546,47 @@ </varlistentry> <varlistentry> + <term><varname>DeferAccept=</varname></term> + + <listitem><para>Takes time (in + seconds) as argument. If set, the + listening process will be awakened + only when data arrives on the socket, + and not immediately when connection is + established. When this option is set, + the + <constant>TCP_DEFER_ACCEPT</constant> + socket option will be used (see + <citerefentry><refentrytitle>tcp</refentrytitle><manvolnum>7</manvolnum></citerefentry>), + and the kernel will ignore initial ACK + packets without any data. The argument + specifies the approximate amount of + time the kernel should wait for + incoming data before falling back to + the normal behaviour of honouring + empty ACK packets. This option is + beneficial for protocols where the + client sends the data first (e.g. + HTTP, in contrast to SMTP), because + the server process will not be woken + up unnecessarily before it can take + any action. + </para> + + <para>If the client also uses the + <constant>TCP_DEFER_ACCEPT</constant> + option, the latency of the initial + connection may be reduced, because the + kernel will send data in the final + packet establishing the connection + (the third packet in the "three-way + handshake").</para> + + <para>Disabled by default.</para> + </listitem> + </varlistentry> + + <varlistentry> <term><varname>ReceiveBuffer=</varname></term> <term><varname>SendBuffer=</varname></term> <listitem><para>Takes an integer |