# RcvBufSize

Requests specific socket receive buffer size; disables auto-tuning.

This parameter applies to imudp: UDP Syslog Input Module.

Name:

  RcvBufSize

Scope:

  input

Type:

  size

Default:

  input=0

Required?:

  no

Introduced:

  7.3.9

## Description

This requests a socket receive buffer of specific size from the operating system. It is an expert parameter, which should only be changed for a good reason. Note that setting this parameter disables Linux auto-tuning, which usually works pretty well. The default value is 0, which means “keep the OS buffer size unchanged”. This is a size value. So in addition to pure integer values, sizes like `256k`, `1m` and the like can be specified. Note that setting very large sizes may require root or other special privileges. Also note that the OS may slightly adjust the value or shrink it to a system-set max value if the user is not sufficiently privileged. Technically, this parameter will result in a `setsockopt()` call with `SO_RCVBUF` (and `SO_RCVBUFFORCE` if it is available). (Maximum Value: 1G)

Examples:

    module(load="imudp") # needs to be done just once
    input(type="imudp" port="514" rcvbufSize="1m")

## Input usage

    input(type="imudp" RcvBufSize="...")

## See also

See also imudp: UDP Syslog Input Module.

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