Graylog2-server: Buffer size warning for Netty inputs

[hc4]

Problem description

Got this line in logs for all my Netty TCP inputs (Syslog and Beats)
[NettyTransport] receiveBufferSize (SO_RCVBUF) for input ... should be 1048576 but is 212992.

What does it mean? Should I set buffer size in input settings to 212992 (default is 1048576)?

Environment

• Graylog Version: 2.0.1

[joschi]

@hc4 That's because your operating system doesn't allow the Java process to increase the socket receive buffer to be increased to 1 MB (1048576 bytes).

You can either reduce the receive buffer size in your input configuration or increase the limit on the operating system level.

See Graylog2/documentation#26 for an explanation.

[hc4]

Maybe there is should be better message?
For example:
requested receiveBufferSize is 1048576, but system allowed only 212992.

Or maybe even better - make this check in UI, when applying Input configuration.