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Diffstat (limited to 'doc/imudp.html')
| -rw-r--r-- | doc/imudp.html | 31 |
1 files changed, 29 insertions, 2 deletions
diff --git a/doc/imudp.html b/doc/imudp.html index a8dbca31..c84b7f9c 100644 --- a/doc/imudp.html +++ b/doc/imudp.html @@ -36,6 +36,16 @@ is provided by the platform. Most useful to select "fifo" for real-time processing under Linux (and thus reduce chance of packet loss). <li><b>SchedulingPriority</b> <number><br> Scheduling priority to use. +<li><b>batchSize</b> <number><br> +This parameter is only meaningful if the system support recvmmsg() (newer Linux +OSs do this). The parameter is silently ignored if the system does not support +it. If supported, it sets the maximum number of UDP messages that can be obtained +with a single OS call. For systems with high UDP traffic, a relatively high batch +size can reduce system overhead and improve performance. However, this parameter +should not be overdone. For each buffer, max message size bytes are statically +required. Also, a too-high number leads to reduced efficiency, as some structures +need to be completely initialized before the OS call is done. We would suggest to not +set it above a value of 128, except if experimental results show that this is useful. </ul> <p><b>Input Parameters</b>:</p> <ul> @@ -75,6 +85,17 @@ are defined for a single input and each of the inputnames shall be unique. Note that there currently is no differentiation between IPv4/v6 listeners on the same port. </li> +<li><b>rcvbufSize</b> [size] - (available since 7.5.3) +This request 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). </ul> <b>Caveats/Known Bugs:</b> <ul> @@ -91,6 +112,13 @@ user account. input(type="imudp" port="514") </textarea> +<p>The following sample is mostly equivalent to the first one, but request a +larger rcvuf size. Note that 1m most probably will not be honored by the OS +until the user is sufficiently privileged.</p> +<textarea rows="3" cols="60">module(load="imudp") # needs to be done just once +input(type="imudp" port="514" rcvbufSize="1m") +</textarea> + <p>In the next example, we set up three listeners at ports 10514, 10515 and 10516 and assign a listner name of "udp" to it, followed by the port number: </p> @@ -110,7 +138,6 @@ input(type="imudp" port=["10514","10515","10516"] inputname="" inputname.appendPort="on") </textarea> - <p><b>Legacy Configuration Directives</b>:</p> <p>Multiple receivers may be configured by specifying $UDPServerRun multiple times. @@ -129,7 +156,7 @@ equivalent to: SchedulingPolicy <li>$IMUDPSchedulingPriority <number> Available since 4.7.4+, 5.7.3+, 6.1.3+.<br> equivalent to: SchedulingPriority </ul> -<p><b>Sample:</b></p> +<p><b>Legacy Sample:</b></p> <p>This sets up an UPD server on port 514:<br> </p> <textarea rows="3" cols="60">$ModLoad imudp # needs to be done just once |